bluuebunny/crossref_metadata_2025_split huggingface dataset:
EFFECTS OF PROGESTERONE ON THE ELECTRICAL ACTIVITY OF THE FOREBRAIN
Authors: LINCOLN D. W. 
Published: December 2008

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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.