bluuebunny/crossref_metadata_2025 huggingface dataset:
THE EFFECT OF THYROXINE ON PERIPHERAL THYROID HORMONE METABOLISM
Authors: GOOLDEN A. W. G. , GARTSIDE JUNE M. , OSORIO C.
Published: December 2008

Blood samples obtained from normal people after an oral dose of 0·4 mg. l-thyroxine showed a depression in the uptake of [131I]tri-iodothyronine ([131I]T3) by the red cells, whereas the uptake by a resin sponge was increased. This depression did not occur when the test was carried out at 20° instead of at 37°. It was reversed when methylthiouracil, which is known to inhibit deiodination, was added to the blood in vitro. These findings are indicative of deiodination as the cause of the depression of T3-red cell (RBC) uptake. T3-RBC uptake was similarly depressed after the administration of l-tri-iodothyronine, and it was concluded that deiodination was promoted in the red cell system whenever there was an increase in the level of circulating thyroid hormone.

The radioactive product of deiodination, which may be an artifact rather than a natural metabolite, has not been identified. Analysis of plasma obtained from blood after incubation with [131I]T3 under the conditions of the T3-RBC test, has not shown any [131I]iodide other than that present as an impurity in the [131I]T3 preparation. It could be shown that the product of deiodination is bound by the red cells but is eluted from them more readily than [131I]T3. It is suggested that the fall in T3-RBC uptake after thyroxine is due to deiodination which results in the formation of some radioactive product which is eluted from the red cells in the washing procedure.
THE IN-VIVO EFFECTS OF SHEEP PITUITARY GONADOTROPHINS ON THE SECRETION OF STEROIDS BY THE AUTOTRANSPLANTED OVARY OF THE EWE
Authors: McCRACKEN J. A. , UNO A. , GODING J. R. , ICHIKAWA Y. , BAIRD D. T.
Published: December 2008

The transplanted ovary preparation in the ewe permits long-term access to both the arterial and venous sides of the ovarian circulation in the unstressed, unanaesthetized animal. However, these animals are not completely normal, as the separation of the ovary from the uterus results in ovarian cycles with a prolonged luteal phase and the infrequent manifestation of behavioural oestrus. Treatment with exogenous gonadotrophins made it possible to carry out direct infusion experiments on the transplanted ovary on a more uniform basis. The effect on ovarian blood flow and on ovarian steroid secretion following the infusion of ovine luteinizing hormone (LH), ovine follicle-stimulating hormone (FSH) or ovine prolactin directly into the arterial supply of the transplanted ovary of the ewe is described. Four infusions of each of the three ovine pituitary gonadotrophins were made into the ovary at rates varying from 0·1 μg./hr. to 1000 μg./hr. LH infusions produced an increase in both ovarian blood flow and steroid secretion at all dosage levels employed. Androstenedione showed the greatest increase (600%) in secretion rate after LH, followed by testosterone (400%), oestradiol (more than 50%) and progesterone (less than 50%). Progesterone however showed the greatest increase in terms of mass of steroid secreted. There was no measurable change in the secretion of oestrone. Ovarian blood flow increased by at least 20% (range 20–125%) within 1 hr. of beginning the LH infusion. On the other hand FSH and prolactin infused at the same or at a higher rate than LH, had essentially no effect on ovarian blood flow or steroid secretion rate. In two out of four FSH infusions there appeared to be a transient fall in progesterone secretion rate. The infusion of 0·9% NaCl solution into the ovary as a control had no effect on blood flow or on steroid secretion.
DEVELOPMENT OF GOITRE AFTER METHYLTHIOURACIL TREATMENT OF MICE WITH HYPOTHALAMIC LESIONS
Authors: MOLL J. , MARTENS E. , JANSEN H. G.
Published: December 2008

Lesions aimed at the area of the paraventricular hypothalamic nuclei were made by means of stereotaxic electrocoagulation in intact and gonadectomized mice, which were subsequently treated with methylthiouracil. Lesions could be placed with an acceptable degree of precision and with moderate postoperative mortality. Correctly placed lesions made in intact females and castrated males caused a marked inhibition of goitre development, indicating a depressed secretion of thyrotrophin. However, in intact males and spayed females inhibition of goitre formation could not be demonstrated convincingly.
THE CLEARANCE OF HOMOLOGOUS CALCITONIN
Authors: WEST T. E. T. , O'RIORDAN J. L. H. , CARE A. D.
Published: December 2008

The plasma clearance of calcitonin (TC) was studied by following the disappearance of radioactivity after intravenous injection of labelled TC, and the disappearance of bio-assayable activity after intravenous injection of unlabelled hormone. The turnover was shown to be rapid: two exponential components were involved with half times of 4–5 and 35–40 min. respectively. Similar values were obtained in experiments in which TC was infused to obtain raised, steady concentrations after which the disappearance of biologically active material was followed for up to 100 min. The normal concentration of TC in porcine peripheral plasma was calculated to be about 9 μu./ml.
OVULATION AND CORPUS LUTEUM FUNCTION IN THE LLAMA (LAMA GLAMA)
Authors: ENGLAND B. G. , FOOTE W. C. , MATTHEWS D. H. , CARDOZO ARMANDO G. , RIERA S.
Published: December 2008

Results in 53 llamas (33 mated animals and 20 controls) showed that ovulation is copulation-induced in this species. Ovulation without copulation occasionally occurred during the height of the recognized breeding season in Bolivia.

The first mating during the luteal phase (12–24 days after the preceding ovulation) resulted in ovulation in four out of ten llamas.

Determination of pituitary luteinizing hormone (LH) content showed the highest level on the day before mating (9·00 μg./mg.) and the lowest level on day 4 (6·25 μg./mg.). LH level on day 8 was significantly higher than on day 4 (7·62 μg./mg.). Corpora lutea (c.l.) were well formed on day 4 after mating (408 mg.), reached a maximum size by day 8 (1920 mg.) and rapidly decreased in size to day 16 (136 mg.). The corpus albicans remained as an entity but decreased in size to 21 mg. on day 120. Similar changes were found in c.l. histology and progesterone content. The combined results indicate that the functional life of the c.l. in a non-pregnant llama is 16 days or less.

Treatment with 25 i.u. human chorionic gonadotrophin was sufficient to cause ovulation in 50% of the animals treated.

A large (150 mg.) dose of norethandrolone did not cause morphological regression of the c.l. when measured 5 days after treatment. Treatment with 5 mg. daily for 14 days caused regression of c.l. as compared with untreated controls and animals treated with oestradiol valerate.
EFFECTS OF PROGESTERONE ON THE ELECTRICAL ACTIVITY OF THE FOREBRAIN
Authors: LINCOLN D. W.
Published: December 2008

Unit activity from the hypothalamus and EEG patterns from the cerebral cortex of rats rendered persistently oestrous by exposure to continuous illumination were analysed during the acute infusion of various progesterone preparations.

Infusion of 400 μg. of progesterone in either 0·1 ml. propylene glycol or ethanol caused dramatic changes in the spike activity of many hypothalamic units and precipitated a reproducible change in the EEG pattern. The infusion invariably caused a prolonged synchronization of the EEG, lasting 30–40 min. (i.e. an EEG pattern of large-amplitude slow waves). In addition, a period of high-amplitude high-frequency EEG waves occurred 2–4 min. after the infusion. These EEG changes were usually concurrent with any changes which occurred in the spike activity of hypothalamic units. Similar changes were observed after the infusion of the control materials, i.e. 0·1 ml. of propylene glycol or ethanol. The inclusion of progesterone did not produce changes in brain activity which were substantially different from the control infusions.

Infusion of up to 400 μg. of progesterone in propylene glycol or ethanol did not change the specific response of hypothalamic units to probing the vaginal parts of the cervix. On the other hand, this treatment frequently abolished the non-specific response (i.e. a response which is related to the period of EEG arousal) of these units for a period of 10–30 min. after infusion. The loss of the non-specific response appeared to be associated with an increase in the intensity of stimulus necessary to cause EEG arousal. This change in arousal threshold was caused, at least in part, by the action of the carrier agents.

The infusion of up to 400 μg. of progesterone in a microcrystalline form in saline caused changes in the activity of many units in the anterior hypothalamus and adjacent regions; both excitatory and inhibitory effects were observed. However, every one of these prominent changes in unit activity was associated with a prolonged period of synchronized EEG. There was no evidence to suggest that progesterone was having any selective action on the hypothalamus.
ROLE OF DEHYDROEPIANDROSTERONE AND ITS SULPHATE IN SYNTHESIS OF TESTOSTERONE BY HUMAN TESTES IN VIVO AND IN VITRO
Authors: RAHEJA M. C. , LUCIS O. J.
Published: December 2008

The synthesis of testosterone from [4-14C]dehydroepiandrosterone (DHEA) and [7α-3H]dehydroepiandrosterone sulphate (DHEA-S) by human testes in vivo and in vitro was investigated. Neither free testosterone nor free DHEA was found in a perfused testis or the spermatic venous plasma after the infusion of [7α-3H]DHEA-S into the spermatic artery in vivo, whereas 3H-labelled free DHEA, testosterone and androstenedione were isolated after incubation of testicular tissue with the same substrate in vitro. Only 14C-labelled testosterone was found in the spermatic venous effluent and in the testis after infusion of a mixture of equimolar amounts of [7α-3H]-DHEA-S and [4-14C]DHEA into the spermatic artery in vivo. Testosterone containing 3H and 14C was isolated after incubation of testicular tissue with a mixture of the two substrates in vitro.
THE DIAGNOSIS OF HYPOPITUITARISM WITH SPECIAL REFERENCE TO THE ESTIMATION OF PLASMA NON-ESTERIFIED FATTY ACIDS
Authors: WILKINSON R. , HALL R. , COOPER A. , NEWELL D. J.
Published: December 2008

Plasma non-esterified fatty acid (NEFA) levels during a standard insulin sensitivity test have been compared in hypopituitary and hospital control patients who had undergone full routine pituitary investigations. Significant impairment of the recovery of plasma NEFA levels after insulin injection was found in the hypopituitary group as a whole, but this finding was not consistent in individual cases. It is concluded that the measurement of NEFA levels is of little value in the diagnosis of mild hypopituitarism. Blood sugar levels after insulin were of no value in the diagnosis of minor degrees of hypopituitarism.

In 19 patients with mild hypopituitarism the order of frequency of deficiency of individual hormones, as judged by tests currently available, was gonadotrophins followed by growth hormone, adrenocorticotrophic hormone, thyroid-stimulating hormone, and antidiuretic hormone.
IN-VIVO ASSAY FOR HYPOTHALAMIC PROLACTIN-INHIBITING FACTOR
Authors: DANON A. , DIKSTEIN S. , SULMAN F. G.
Published: December 2008

Treatment of intact adult male rats with 10 mg. perphenazine (Trilafon)/kg. resulted in a decrease in the prolactin content of the pituitary within 1 hr. This decrease was probably due to suppression of the hypothalamic prolactin-inhibiting factor (PIF). Subsequent intracarotid infusion of neutralized acid extracts of rat hypothalamus restored the pituitary prolactin content. This effect was dose-dependent within a range of ½-2 hypothalami. Infusion of extracts of cerebral cortex failed to increase pituitary prolactin. The response to the hypothalamic extracts is considered to be specific for PIF and is proposed as an assay method for PIF.
QUANTITATIVE DETERMINATION OF IODOAMINO ACIDS IN THE THYROID GLAND OF THE PARROT-FISH (SCARUS GUACAMAIA)
Authors: MATTY A. J. , THORNBURN C. C.
Published: December 2008

A quantitative analysis of the iodoamino acids in whole dried parrot-fish thyroid gland was carried out by determination of stable 127I. Mono- and di-iodotyrosine together made up about half of the total iodoamino acids and thyroxine about a third to a half. The tri-iodothyronine content was low, about 5%. The total content of the acids increased with body weight, and there was an indication of a sex difference.
EFFECTS OF PROGESTERONE IN VITRO ON GLUCOSE AND ACETATE METABOLISM BY THE LUTEINIZED RAT OVARY
Authors: FLINT A. P. F.
Published: December 2008

Progesterone in vitro decreases the rates of glucose uptake and of acetate uptake and oxidation, of lipogenesis from acetate and of oxygen consumption, and reduces the intracellular concentrations of ATP and citrate in slices of luteinized rat ovary incubated in a bicarbonate-buffered medium. The effect on glucose uptake was shown to be due to inhibition by progesterone of the membrane transport of glucose. In view of the steroid concentrations used to elicit these effects in vitro and the known actions of steroids such as progesterone on biological membranes, these observations are thought to be due to non-physiological lytic effects.
COMPARISON OF PAPER AND THIN-LAYER RADIOCHROMATOGRAPHY FOR THE QUANTITATIVE ANALYSIS OF THYROIDAL IODOAMINO ACIDS
Authors: ENSOR JANICE M. , KENDALL-TAYLOR PAT
Published: December 2008

Paper and thin-layer radiochromatography have been applied both to the analysis of iodine-containing compounds discharged by mouse thyroid glands maintained in vitro and to their distribution in hydrolysates of the gland. The results are in close agreement. The addition of thyroid-stimulating hormone to the medium supporting the mouse thyroid glands increased the release of labelled iodothyronines.

Compared with paper, thin-layer chromatography separated thyroxine and tri-iodothyronine more effectively; there was also less deiodination and a higher degree of reproducibility and reliability.
AN ELECTROPHYSIOLOGICAL STUDY IN THE EWE OF THE TRACTS WHICH TRANSMIT IMPULSES FROM THE MAMMARY GLANDS TO THE PITUITARY STALK
Authors: RICHARD PH.
Published: December 2008

Potentials were recorded in the pituitary stalk of ewes after electrical stimulation of the inguinal nerves or dilatation of the vagina. The modifications provoked by destruction of sensory pathways at different levels in the central nervous system were studied with a view to defining the tracts which carry the impulses to the pituitary stalk. The potentials obtained with bipolar concentric electrodes were characterized by long latency and a negative wave of low amplitude and long duration. The apparent negativity of the response was due to the recording conditions. At the spinal level the tracts are bilateral but primarily contralateral. The dorsal tracts do not seem to be necessary for the transmission of impulses to the pituitary stalk and the nerve fibres are distributed diffusely in the lateral and ventral parts of the spinal cord. At the supraspinal level, the lemniscal system does not seem to be involved in this transmission. On the other hand, the passage of impulses needs the integrity of the mesencephalic reticular formation. The long latency of the responses of the pituitary stalk to electrical stimulation of the inguinal nerves was due to the transmission time of the impulses between the mesencephalic level and the pituitary stalk. This long latency does not originate in the periphery. The cause has not been determined but relay in the amygdala nuclei or in the cortex has been eliminated.

The relationship between the potentials evoked in the pituitary stalk by the stimulation of the inguinal nerves or by vaginal dilatation and the release of oxytocin is discussed.
THE GAS-LIQUID CHROMATOGRAPHY OF STEROID FORMATES; AN APPLICATION IN CONGENITAL ADRENAL HYPERPLASIA
Authors: MAKIN H. L. J.
Published: December 2008

The gas-liquid chromatography (GLC) of some C19 steroid formates has been investigated in an attempt to speed up the final stages of the estimation of the 11-oxygenation index. SE-30 was found to give the best separation of the urinary C19 steroids formed after borohydride reduction and periodate oxidation of urine. Formates, acetates, propionates, n-butyrates, valerates and trimethylsilyl ethers were examined; formate esters gave the best separation of androsterone and aetiocholanolone. Estimation of the 11-oxygenation index by GLC increases the specificity and speed of single estimations and it is suggested that this method may find use as a rapid screening test for abnormal urinary steroid patterns.
THE ROLE OF THE PARATHYROID GLANDS IN THE ABSORPTION OF CALCIUM FROM THE SMALL INTESTINE
Authors: WINTER M. , MORAVA E. , SIMON G. , SÓS J.
Published: December 2008

The absorption of calcium from duodenal and jejunal segments of the small intestine was studied in rats using an in-vivo loop technique. Previous parathyroidectomy decreased calcium absorption from both segments in rats fed a normal diet. Reduced calcium transport was greater in rats fed a calcium-deficient diet after parathyroidectomy. The slower clearance of radioactive calcium from the lumen of the intestine was not due to increased endogenous calcium excretion. Thyroidectomy, either alone or combined with parathyroidectomy, decreased calcium absorption but the effect of thyroidectomy alone requires further study. The decrease in calcium absorption after removal of the parathyroids was minimal or absent when the animals were fed a high calcium, low phosphorus, vitamin D-deficient diet or fasted 48 hr. before the experiment.
THE EFFECT OF PROLACTIN ON THE SECRETORY ACTIVITY OF THE NASAL SALT-GLAND OF THE DOMESTIC DUCK (ANAS PLATYRHYNCHOS)
Authors: PEAKER M. , PHILLIPS J. G. , WRIGHT A.
Published: December 2008

When injected intravenously, 20 i.u. ovine prolactin significantly enhanced the output of fluid from the minimally stimulated nasal salt-gland of ducks within 5 min. This effect persisted for a further 5 min. In ducks which were still producing nasal fluid 25 min. after prolactin administration, a second enhancement of secretion was observed which could be related to an indirect effect induced by a rise in the blood glucose concentration. The initial, rapid enhancement of secretion could not be attributed to changes in blood composition and it seems possible that prolactin may have a direct effect on the avian salt-gland.
BINDING OF CORTICOSTERONE IN RAT LIVER
Authors: SNART R. S. , SANYAL N. N. , AGARWAL M. K.
Published: December 2008

The binding characteristics of corticosterone by rat liver were studied by a displaceable binding technique. The binding of corticosterone to protein fractionated by gel filtration and density gradient centrifugation has been carried out as a preliminary determination of the nature of the binding sites. The results were analysed and showed three types of binding sites for corticosterone with the characteristic association constants at 0° of K1 = 1·2 × 1010, K2 = 1 × 108 and K3 = 1 × 104 1./mole. Percentage displacement of corticosterone from the nuclear fraction did not differ significantly from that from tissue or the mitochondrial-microsomal fraction. The K1 and K2 sites persisted in separated buffer-soluble fractions but were destroyed on mild heating leaving only the K3 sites.
RESPIRATORY AND ENZYMIC CHANGES IN RESPONSE TO STEROID HORMONES
Authors: DALTON T. , SNART R. S.
Published: December 2008

Changes in respiration and enzymic activity were measured in toad bladder tissue and homogenates in response to aldosterone and in rat liver tissue and homogenates in response to corticosterone. The results showed that the stimulation of target tissue may be associated with the saturation of two types of receptor sites for these hormones. The mechanism of action of both hormones is discussed in terms of a common effect on the control of respiration of the target tissue, and a second effect on the control of cellular processes such as the entry of sodium into the epithelial cells of toad bladder or increased transaminase activity in rat liver.
THE EFFECT IN VITRO OF THYROXINE, GLUCAGON, THYROTROPHIN AND ANTITHYROID DRUGS ON 'USUAL' AND 'ATYPICAL' HUMAN PLASMA CHOLINESTERASE
Authors: WHITTAKER MARY
Published: December 2008

SMUMARY

Concentrations of thyroxine above 10-7m inhibited the activity of the 'usual' and 'atypical' human plasma cholinesterase in vitro. The 'atypical' enzy mewas more readily inhibited and the ratio of the I50 atypical: I50 usual indicates that the hormone can be used as a differential inhibitor to identify the two phenotypes. Similar results were obtained with thiourea, but the action of thiouracil appeared to differ in so far as this inhibited both enzymes to the same extent. Neither glucagon nor thyroid stimulating hormone had any effect.
THE EFFECTS OF HYPOPHYSECTOMY AND TESTOSTERONE ON THE ACTIVITY OF THE SEBACEOUS GLANDS OF CASTRATED RATS
Authors: THODY A. J. , SHUSTER S.
Published: December 2008

Adult male rats which had been castrated prepuberally secreted less sebum than intact rats. When hypophysectomy followed castration there was a further decrease in sebum secretion. Treatment of the castrated and hypophysectomized castrated rats with testosterone propionate produced a large and comparable increase in the sebum secretion of both groups. Testosterone propionate also caused a marked increase in the preputial gland weight of the castrated rats, although a much smaller response occurred after hypophysectomy. The effect of hypophysectomy on the response of the sebaceous and preputial glands to testosterone is discussed.
EFFECT OF ADRENOCORTICOTROPHIC AND GROWTH HORMONES ON ALDOSTERONE PRODUCTION AND PLASMA RENIN ACTIVITY IN CHRONICALLY HYPOPHYSECTOMIZED SODIUM-DEFICIENT RATS
Authors: PALKOVITS M. , DE JONG W. , VAN DER WAL B. , DE WIED D.
Published: December 2008

Hypophysectomy abolishes the aldosterone secretory response to sodium deficiency in rats. Sodium deficiency causes a significant increase in plasma renin activity in chronically hypophysectomized rats which is of the same order as that found in intact animals.

Long-term treatment with either adrenal maintenance doses of corticotrophin (ACTH) or with growth hormone (STH) did not affect the low rate of aldosterone production of hypophysectomized rats on a sodium-deficient diet. However, ACTH and STH given simultaneously restored the aldosterone secretory response to sodium deficiency in chronically hypophysectomized rats.

The plasma renin activity of hypophysectomized rats on a sodium-deficient or a normal diet remained unaltered during treatment with either ACTH or STH or with the two hormones given simultaneously. This was also reflected in the systolic blood pressure of rats which, under the conditions used, did not change when the animals were sodium-deficient, or after hypophysectomy or hormone treatment.

These results indicate that the effect of STH, in restoring the aldosterone secretory response to sodium deficiency in the presence of adrenal maintenance doses of ACTH in chronically hypophysectomized rats, is independent of changes in the renin-angiotensin system.
EFFECT OF HYPOTHALAMIC EXTRACTS AND EXOGENOUS PROLACTIN ON REACCUMULATION OF PROLACTIN IN THE PITUITARY OF THE LACTATING RAT AFTER SUCKLING
Authors: GROSVENOR C. E. , MENA F. , MAIWEG H. , DHARIWAL A. P. S. , McCANN S. M.
Published: December 2008

The reaccumulation after suckling of prolactin by the pituitary of spayed lactating rats was significantly increased after a single s.c. injection of acidic extract of rat hypothalamus (stalk-median eminence region) given at the start of the reaccumulation period. Injection of ammonium acetate, an extract of ovine hypothalamus rich in luteinizing hormone-releasing factor (LH-RF), extract of rat occipital cortex or oxytocin was ineffective. An extract of ovine hypothalamus rich in prolactin-inhibiting factor (PIF) (0·15 ml./rat) blocked the fall in pituitary prolactin concentration induced by suckling, but in the same or higher (0·3 ml.) doses neither increased nor depressed the reaccumulation of prolactin after suckling. A single s.c. injection after suckling of 2–8 mg. ovine prolactin in each of four instances significantly increased the amount of prolactin reaccumulated by the pituitary. The level attained was equal to or greater than that resulting from injecting rat hypothalamic extract. These results suggest that the increased blood level of prolactin after suckling stimulates the reaccumulation of prolactin in the pituitary possibly indirectly via a factor or factors in the hypothalamus.
THE IDENTIFICATION OF C19-16-UNSATURATED STEROIDS AND ESTIMATION OF 17-OXOSTEROIDS IN BOAR SPERMATIC VEIN PLASMA AND URINE
Authors: GOWER D. B. , HARRISON F. A. , HEAP R. B.
Published: December 2008

C19-16-unsaturated steroids have been extracted from the urine and spermatic vein plasma of a mature boar and identified by thin-layer chromatography, gas—liquid chromatography and combined gas—liquid chromatography—mass spectrometry. 5α-Androst-16-en-3β-ol (approximately 250 μg./1.) was identified in the urinary glucuronide fraction. This compound and the 3α-epimer occurred in the spermatic vein plasma predominantly as sulphates but a small quantity of the 3α-isomer was extractable with ether prior to hydrolysis of steroid conjugates. Traces of 5,16-androstadien-3β-ol have been tentatively identified in the plasma sulphate fraction; 5α-androst-16-en-3-one occurred as free steroid. No 16-unsaturated steroids were found in the plasma glucuronide nor in urinary sulphate fractions. The latter contained an unidentified compound of similar polarity to the C19-16-unsaturated steroids.

Neutral 17-oxosteroids were measured in extracts obtained from both the urine and spermatic vein plasma. Of the dehydroepiandrosterone (DHA) in the urine 60% occurred as sulphate and 40% as glucuronide with only traces as free steroid. Androsterone and aetiocholanolone occurred only as glucuronides. In the spermatic vein plasma, DHA occurred predominantly as sulphate with small amounts as glucuronide and free steroid.
PHYSIOLOGICAL VARIATIONS IN PROLACTIN CONTENT OF THE MOUSE PITUITARY GLAND EXAMINED BY DISC ELECTROPHORESIS AND BIOASSAY
Authors: NICHOLSON PATRICIA M.
Published: December 2008

Polyacrylamide disc gel electrophoresis was used to study the prolactin content of individual and pooled mouse pituitary glands. Gels containing 15% acrylamide were found to separate prolactin from serum albumin whereas 7% acrylamide gels did not.

Changes in the width of the prolactin band were observed during pregnancy and lactation but the method was found to be unsuitable for quantitative analysis of the prolactin content of individual pituitaries.
HOMOTRANSPLANTATION OF OVARIES WITH VASCULAR ANASTOMOSES IN RABBITS: RESPONSE OF TRANSPLANTS TO HUMAN CHORIONIC GONADOTROPHIN
Authors: BETTERIDGE K. J.
Published: December 2008

A technique is described for the transplantation of ovaries in rabbits. Segments of aortae and venae cavae were included in grafts and implanted by means of the Vogelfanger-NRC blood vessel stapler into transected analogous vessels in recipients. As used ultimately, the procedure gave a survival rate of 14/18 recipients (11 with some paraplegia) and 12/14 grafts. Only one surviving graft ovulated in response to the first postoperative injection of human chorionic gonadotrophin (HCG) (50 or 100 i.u.) but follicles usually showed marked growth with or without petechial haemorrhages in their walls and then became luteinized. The response was shown to be specific for gonadotrophic stimulation and not a consequence of the operation. HCG given immediately postoperatively induced graft responses less consistently (2/6) than when injected 4 or 24 hr. later (6/7). Most recipient's own ovaries also failed to respond fully to the earlier injections. Ways in which circulatory disturbances may account for subovulatory responses are discussed. Grafts survived functionally for up to 6 days and follicles maturing after transplantation ovulated more readily in response to HCG (17 ovulations in 2/4 grafts). Beyond day 13, three grafts were rejected, no therapy being given to prolong their survival.
THE SYNTHESIS OF DNA AND RNA IN HUMAN CARCINOMATOUS ENDOMETRIUM IN SHORT-TERM INCUBATION IN VITRO AND ITS RESPONSE TO OESTRADIOL AND PROGESTERONE
Authors: NORDQVIST S.
Published: December 2008

Twenty-five endometrial carcinomas and three non-endometrial carcinomas were studied for the influence of various steroid hormones on the synthesis of DNA and RNA in short-term incubations in vitro. Endometrial carcinomas showed a dose-dependent sensitivity to progesterone in vitro, the response in both nucleic acids sometimes exceeding that of normal endometria. The mean reduction in DNA synthesis was to 46% and in RNA synthesis to 39% of the control values. Poorly differentiated carcinomas showed higher values of DNA synthesis than highly differentiated ones, as did carcinomas from younger women compared with those from older women. The response in vitro to progesterone was not correlated with these factors. Pregnenolone and a synthetic progestogen were less effective in vitro than progesterone. Oestradiol at a high concentration (20 μg/ml) in some cases significantly reduced the synthesis of both nucleic acids, possibly because of a specific 'toxic' action on the cells. No hormonal effects were observed in non-endometrial carcinomas.
COMPARISON OF TESTS OF HYPOTHALAMO-PITUITARY-ADRENOCORTICAL FUNCTION IN PITUITARY DISEASE
Authors: DOAR J. W. H. , WYNN V. , WEBB P. J.
Published: December 2008

The use of the resting plasma cortisol level, the diurnal plasma cortisol rhythm and plasma cortisol response to a maximal adrenocorticotrophic hormone (ACTH) infusion or insulin-induced hypoglycaemia as indirect tests of hypothalamo—pituitary—adrenocortical function was examined in a group of 27 patients with pituitary disease. While the first three tests provided similar information about hypothalamo—pituitary—adrenocortical function, the plasma cortisol response to insulin-induced hypoglycaemia did not provide further clinically useful information. Difficulties in interpretation of dynamic tests of hypothalamo—pituitary—adrenocortical function are discussed.
METABOLISM OF [14C]ETHYNYLOESTRADIOL IN THE BABOON
Authors: KULKARNI B. D.
Published: December 2008

The amounts of radioactivity in the plasma and in the urine of two normally cycling baboons was studied after intravenous administration of [14C]ethynyloestradiol labelled in the ethynyl side-chain. Within 6 days 76·9–83·3% of the dose was excreted in the urine; 36·4–50·9% appeared on the day of injection, and radioactivity continued to be excreted to the extent of 2·4–2·9% even on day 6. Of the urinary conjugates isolated by neutral resin chromatography, enzymic hydrolysis and solvolysis liberated 57·2–70·5% and 14% of radioactivity respectively. Paper chromatography of the β-glucuronidase-liberated fraction with an intact ethynyl group suggested the presence of at least 11 metabolites. Peaks of radioactivity were found among the more polar compounds which barely moved from the starting line, and among compounds similar in polarity to the administered steroid. The chromatographic results with the metabolites suggest that hydroxylation is an important metabolic pathway for ethynyloestradiol in the baboon.
EFFECT OF A SINGLE INJECTION OF CHLORPROMAZINE INTO INFANT MALE RATS ON SUBSEQUENT GONADOTROPHIN SECRETION
Authors: LADOSKY W. , KESIKOWSKI W. M. , GAZIRI I. F.
Published: December 2008

A single injection of 20 μg chlorpromazine/g body weight into male rats 10 days after birth accelerated spermatogenesis when the animals were 45 days old; this was not observed in rats injected on days 1, 5, 8, 12 or 15 of life. When half an ovary was grafted into the eye of rats treated on day 10, they showed a higher incidence of luteinization than ovarian grafts in rats treated at any other age. Compared with animals surgically castrated at the same age, chlorpromazine did not act as by 'pharmacological castration', but induced some alteration in the brain which promoted higher secretion of luteinizing hormone, characteristic of the female pattern of gonadotrophin control, as demonstrated by accelerated spermatogenesis and a higher degree of luteinization. These results suggest that the sexual differentiation of the brain occurs on about the 10th day of postnatal life and can be blocked by chlorpromazine.
ENTEROHEPATIC CIRCULATION OF BILIARY [4-14C]PROGESTERONE METABOLITES IN THE RABBIT
Authors: SENCIALL I. R. , THOMAS G. H.
Published: December 2008

Two rabbits were injected intravenously with [4-14C]progesterone and the bile and urine collected for 6 h. The crude bile was administered through an intraduodenal cannula to four rabbits as a single injection, and to three rabbits at a constant rate of infusion for 1·5 h. Bile and urine were collected hourly for up to 7 h. In the single injection experiments 42·3–64·4% of the radioactivity was excreted in the bile and 3·8–13·5% in the urine in 5–6 h. After constant rate infusion 35·4–64·8% and 4·7–9·5% of the radioactivity was excreted in the bile and urine respectively during 6–7 h. The hourly recovery of radioactivity in the neutral fractions of bile and urine decreased with time, whereas radioactivity not accounted for increased. Acidic metabolites represented an insignificant proportion of both biliary and urinary metabolites after enterohepatic recirculation.
THE EFFECT OF ABNORMAL MATERNAL PLASMA CALCIUM LEVELS ON THE OFFSPRING OF RATS
Authors: FAIRNEY ANGELA , WEIR A. A.
Published: December 2008

Study of the offspring from parathyroidectomized and hypercalcaemic rats showed that both high and low levels of maternal plasma calcium produced abnormalities in the offspring. Both groups of offspring had hypocalcaemia at birth which reverted to normal by the 7th day of life. All the offspring grew poorly compared with controls. The growth defect in the offspring of the hypocalcaemic rats was reversed if the offspring were reared by normal rats, and in the offspring of the hypercalcaemic rats was accompanied by abnormalities of the fur, including focal alopecia, which reverted to normal when the offspring were weaned on to a normal diet. The calcium concentration in the milk of the hypercalcaemic rats was higher than that in the milk of normal and parathyroidectomized rats.

In the rat the plasma and milk calcium levels in the mother appeared to be important in the aetiology of neonatal hypocalcaemia and growth. It is suggested that the estimation of the plasma calcium in the mother should become a routine procedure in the investigation of cases of neonatal tetany in infants.
THE EFFECTS OF AN INTRA-UTERINE DEVICE ON UTERINE CELL DIVISION AND EPITHELIAL MORPHOLOGY DURING EARLY PREGNANCY IN THE MOUSE
Authors: MARTIN L. , FINN C. A.
Published: December 2008

Intra-uterine silk threads in mice prevented the development of a normal progestational epithelium and closure of the uterine lumen on day 5 of pregnancy. It seems likely that either of these effects would prevent implantation.

The intra-uterine device (IUD) produced an abnormal type of luminal epithelium resembling somewhat the hyperplastic type produced by oestrogen treatment, and characterized by increased cytoplasmic basophilia and irregularly placed, swollen nuclei with prominent nucleoli. The IUD also increased the numbers of mitoses in the luminal epithelium. This mitogenic effect was not due simply to inhibition of the suppressive action of progesterone since mitosis was increased on day 3 when progesterone is probably not involved.

All these effects were seen in regions of the uterus remote from the site of the IUD, which suggests that they are caused by factors released into the uterine lumen. In contrast, the effects of the IUD on the glands and stroma appeared to be restricted to the immediate vicinity of the IUD.

It is suggested that IUD's might prevent implantation by stimulating the production of substances which antagonize the actions of progesterone on the uterine luminal epithelium.
AUTOTRANSPLANTATION OF THE PANCREAS IN SHEEP: INSULIN SECRETION FROM THE TRANSPLANT
Authors: BELL J. P. , SALAMONSEN L. A. , HOLLAND G. W. , ESPINER E. A. , BEAVEN D. W. , HART D. S.
Published: December 2008

A method of transplanting a part of the pancreas into an exteriorized carotid artery—jugular vein loop in the neck of the sheep is described.

Glucose and butyrate solutions were infused directly into the transplanted pancreas and shown to be powerful direct stimuli of insulin secretion by the pancreatic transplant. Patterns of insulin secretion during prolonged infusions of glucose and butyrate solutions into the pancreatic transplant are described.

One of the sheep described here died 5 months after the transplantation. The other three sheep are all surviving in healthy condition 9, 12 and 18 months respectively, after the transplantation. The transplants of these three sheep continue to secrete insulin.
UPTAKE AND LOSS OF TRITIATED OESTRADIOL BY THE ADRENAL GLAND AND BY OESTROGEN-INDUCED ADRENOCORTICAL CARCINOMA IN THE RAT
Authors: MOBBS BETTY G.
Published: December 2008

The loss of injected tritiated oestradiol from the adrenals of non-tumour-bearing rats of different endocrine status and from the adrenals and tumours of animals bearing two lines of transplantable oestrone-induced adrenocortical carcinoma has been studied. There was no evidence that adrenals from non-tumour-bearing rats behaved as 'target organs' for oestrogen as regards retention of the hormone. As compared with skeletal muscle of the same animals, one tumour line and the host adrenals behaved in a similar way to normal adrenals and did not retain oestradiol, whereas the other tumour line and host adrenals lost the hormone at a somewhat slower rate than muscle.

It is suggested that the behaviour of the host adrenals and of the transplanted tumours regarding the injected oestrogen was determined more by the hormonal environment of the tissues including the contribution made by the tumour itself, than by specific oestrogen receptors in adrenal tissue.
IDENTIFICATION OF FOUR TYPES OF STEROID BY THEIR INTERACTION WITH MINERALOCORTICOID RECEPTORS IN THE TOAD BLADDER
Authors: ALBERTI K. G. M. M. , SHARP G. W. G.
Published: December 2008

The effects of various steroids on sodium transport across the toad bladder were examined in vitro. Cortisone, alone, had no effect on sodium transport but was an antagonist of aldosterone. Cortisone was shown to bind to the two non-specific binding sites for steroids in the nucleus of the toad bladder epithelial cells when present at a concentration of 10−7m. At higher concentrations it interacted with the mineralocorticoid receptors and displaced aldosterone from these sites. Cortexolone had a weak stimulating effect on sodium transport and also antagonized the effect of aldosterone. Cortexolone, when present in excess, displaced aldosterone from its receptor sites.

Four types of steroid could be differentiated by their interaction with the mineralocorticoid receptor sites and the subsequent biological response: (a) steroids that bind to the receptors and produce the full biological effect on sodium transport; (b) steroids that do not bind and therefore are incapable of producing a response; (c) steroids that bind to the receptor sites, have no effect alone but inhibit the action of aldosterone; (d) steroids that bind to the receptor sites, produce a partial response on sodium transport and subsequently antagonize the action of aldosterone.

Multiple points of attachment are postulated for the steroid—receptor interaction.
THE IMMUNOLOGICAL PROPERTIES OF PORCINE PARATHYROID HORMONE
Authors: WOODHEAD J. S. , O'RIORDAN J. L. H.
Published: December 2008

Porcine parathyroid hormone has been isolated and purified. Its size and charge properties are similar to those of bovine and human parathyroid hormones and in a bioassay system the response to porcine hormone is parallel to that of bovine parathyroid hormone. Porcine parathyroid hormone has been labelled with 125I. The immunological properties of the porcine hormone were compared with human and bovine parathyroid hormone in a radioimmunoassay system using antisera against bovine parathyroid hormone. When labelled bovine parathyroid hormone was used as a tracer in the radioimmunoassay, porcine parathyroid hormone could be shown to differ immunologically from the hormones of the other two species. When labelled porcine hormone was used as tracer, it was displaced equally well by hormone from all three species, so that in addition to regions of difference in the molecule there are probably regions of similarity.
EARLY ACTION OF OESTROGEN ON THE INCORPORATION OF [3H]URIDINE IN THE BLASTOCYST AND UTERUS OF RAT DURING DELAYED IMPLANTATION
Authors: MOHLA SURESH , PRASAD M. R. N.
Published: December 2008

The incorporation of [3H]uridine into RNA in the blastocyst and uterus has been studied autoradiographically during delayed implantation and after treatment with oestrogen.

Minimal RNA synthesis, as judged by the accumulation of perchloric acid-precipitable isotope originating from [3H]uridine, was seen in the blastocyst during delayed implantation. Treatment with oestrogen enhanced, within 5 min, incorporation of [3H]uridine in a number of cells in all regions of the blastocyst; there was a fourfold increase in the number of grains/cell and the uptake was predominantly located in the nucleus. The number of grains/cell in the blastocyst gradually increased from fourfold at 15 and sixfold at 30 min to a maximal tenfold increase at 60 min after treatment with oestrogen.

Minimal RNA synthesis was seen in the uterus during delayed implantation. Treatment with oestrogen resulted, within 5 min, in a threefold increase in the number of labelled uterine epithelial cells and a sixfold increase in the number of grains/cell in the uterine epithelial nuclei; this level remained the same at 15, 30 and 60 min after hormone treatment. The significance of these results is discussed in relation to early action of oestrogen on the uterus and blastocyst. It is likely that activation of the delayed blastocyst may involve some mechanism which alters cell permeability.
A SOLID PHASE RADIOIMMUNOASSAY FOR OVINE PROLACTIN
Authors: McNEILLY JUDITH R.
Published: December 2008

A solid phase-antibody system is described for the radioimmunoassay of ovine prolactin. The sensitivity of the method is equal to 0·5 ng of prolactin/ml. Prolactin was measured in the serum of pregnant and lactating ewes; the levels increased at 5 weeks before parturition and then decreased during the following 3 weeks. A second peak of prolactin was observed at parturition and then the levels gradually decreased during the first 3 weeks post partum.
INDUCTION OF OVULATION IN THE GUINEA-PIG
Authors: REED MAY , HOUNSLOW W. F.
Published: December 2008

Ovulation has been induced in the cyclic guinea-pig at a time when the ovaries contain mature follicles, by a single injection of purified luteinizing hormone (LH), follicle-stimulating hormone or guinea-pig gonadotrophins from homogenates of female guinea-pig anterior pituitaries. An injection of any one of the substances given too early only caused follicular luteinization and the ova were retained, even with increased dosage. A single injection of LH in mid-dioestrus caused 'LH effects' on the follicles (destruction of the growing follicles), giving a histological picture similar to that which obtains at the time of ovulation in the untreated animal. Homogenates of anterior pituitaries taken from donor guinea-pigs 1–2 days before ovulation was due (but not at any other time in the cycle) when injected into recipients at middioestrus had similar effects on the follicles. Donor anterior pituitaries taken from guinea-pigs in which ovulation had been inhibited by daily injections of progesterone, caused ovulation in recipients with mature ovarian follicles or 'LH effects' in those in mid-dioestrus. It is suggested that in the guinea-pig there is a basal secretion of gonadotrophins during most of the cycle. A day or two before ovulation occurs and when the ovaries already contain ripe follicles, there is a marked increase in the synthesis of LH which is then released from the anterior pituitary gland and rupture of the follicles occurs.
ADRENAL STEROIDS AND THE ELECTRICAL POTENTIAL OF RAT SMALL INTESTINE IN VIVO
Authors: NOBLE H. M. , MATTY A. J.
Published: December 2008

Using a new technique for determining transmucosal electrical potential difference (p.d.) and short-circuit current (Isc.) in the rat small intestine in vivo it would appear that aldosterone had no direct effect on these parameters of intestinal activity. However, adrenalectomy decreased the Isc. while after adrenalectomy aldosterone and cortisol (hydrocortisone) restored the lowered independent and probably also the lowered dependent (hexose) Isc.
ENHANCEMENT OF ON-TIME NIDATIONS IN SUCKLING PREGNANT MICE BY THE PROXIMITY OF STRANGE MALES
Authors: BLOCH SUZANNE
Published: December 2008

Female mice, mated at the post-partum oestrus and suckling six young, were exposed to the odour of 'strange' and 'alien' males. The proximity of the males caused nidation, usually delayed during lactation, to occur on time in a great proportion of females. The results are comparable to those obtained by administration of oestrogen to suckling and non-suckling females and it is suggested that the odour of the males brings about a secretion of follicle-stimulating hormone and oestrogen. This secretion might be the cause of the olfactory pregnancy-block in non-suckling females (Bruce effect). In suckling pregnant females pregnancy is blocked in a smaller proportion than in non-suckling ones.
PROGESTERONE SYNTHESIS IN RESPONSE TO LUTEINIZING HORMONE BY RAT OVARIAN TISSUE IN VITRO
Authors: WATSON J.
Published: December 2008

A bioassay for luteinizing hormone (LH) activity is described. The method depends on progesterone synthesis by pooled, sliced rat ovarian tissue in vitro, the ovaries being obtained from immature rats pretreated with pregnant mare serum gonadotrophin.

The main advantage of the method is its increased sensitivity compared with the commonly used ovarian ascorbic acid depletion assay, its high degree of precision, and the fact that it allows the use of large numbers of well randomized samples from a small group of animals.
THE BIOASSAY OF LONG-ACTING THYROID STIMULATOR: A COMPARISON OF TWO METHODS
Authors: ENSOR JANICE M. , KENDALL-TAYLOR PAT , MUNRO D. S. , SMITH B. R.
Published: December 2008

The McKenzie (1958) assay method and an in-vitro assay method (Brown & Munro, 1967) for the determination of long-acting thyroid stimulator have been compared. Differences in the results were not great: the in-vitro method is simpler to perform and more precise. The sensitivity of the two methods is similar.

The in-vitro method, when used with antiserum to thyroid-stimulating hormone in the medium, provided a satisfactory and simple means for the assay of long-acting thyroid stimulator in the serum of thyrotoxic patients.
EFFECTS OF OVARIECTOMY OR HYPOPHYSECTOMY ON DAY ONE OF PREGNANCY ON DEVELOPMENT AND TRANSPORT OF FERTILIZED RAT EGGS
Authors: WU J. T. , DICKMANN Z. , JOHNSON D. C.
Published: December 2008

The development of fertilized eggs and their transport through the oviduct were studied in rats ovariectomized or hypophysectomized on day 1 of pregnancy. When killed on day 5 of pregnancy, 100%, 66% and 27% of the eggs were in the uterus of intact controls, ovariectomized and hypophysectomized rats, respectively. Thus both ovariectomy and hypophysectomy retarded transport of a proportion of the eggs. Ninety-nine per cent, 72% and 78% of the eggs were in the blastocyst stage in intact controls, ovariectomized and hypophysectomized rats. The remainder of the eggs were either morulae or degenerated.

Blastocysts and morulae recovered from the hypophysectomized rats were transferred to the uteri of pseudopregnant recipients: 52–57% developed into normal term foetuses compared to 57% for intact controls.

In hypophysectomized rats killed in the morning of day 6, the number of eggs recovered was greatly reduced as compared with rats killed on day 5. This loss of eggs was prevented by placing a ligature at the cervical end of the uterus in the morning of day 5. It was therefore concluded that the eggs had been expelled from the uterus into the vagina between days 5 and 6.