bluuebunny/crossref_metadata_2025 huggingface dataset:
THE CONVERSION OF PREGNENOLONE TO A MORE ACTIVE PROGESTATIONAL SUBSTANCE BY INCUBATION WITH ENDOCRINE TISSUES IN VITRO
Authors: NISSIM J. A. , ROBSON J. M.
Published: December 2008

Incubation of pregnenolone with minced beef corpora lutea resulted in conversion of the steroid to a more active progestational substance as shown by biological assay on the endometrium of the spayed rabbit. Control studies with non-incubated pregnenolone and corpus luteum incubated without steroid, injected separately and in combination, all yielded negative results.

To exclude bacterial action, experiments were repeated under sterile conditions, but without diminution in conversion activity.

Negative results were obtained when pregnenolone was incubated with spleen, liver or ovaries. The incubation of this steroid with beef adrenal and human placenta, however, resulted in active conversion.

It is noteworthy that the adrenal appears to be even more active in the conversion of pregnenolone than the corpus luteum. The association exhibited by the adrenal gland of a lower progesterone content and greater conversion activity, as compared with the corpus luteum, points to progesterone as a likely intermediate substance in the synthesis of the adrenal corticoids.
THE EFFECT OF FIGHTING ON THE ADRENALS, THYMUS AND SPLEEN OF THE VOLE (MICROTUS AGRESTIS)
Authors: CLARKE J. R.
Published: December 2008

1. An attempt has been made to put Chitty's hypothesis, which explains population cycles in the vole (Microtus agrestis) [Chitty, 1952], to an experimental test by studying the effect of fighting on these animals.

2. When strange voles are added to a cage containing a pair of 'resident' voles, the strangers are viciously attacked by the residents. As a result of these attacks there is a pronounced increase in the weight of the adrenal glands and the spleen, and a decrease in the weight of the thymus, of the strange voles. The observed weight changes in these organs were statistically significant.

3. The weight changes in the adrenals and in the thymus of the strange voles can be explained by assuming a disturbance of the adreno-pituitary system of the animals concerned. Interpretation of the increased weight of the spleen is less straightforward, but the enlargement may indicate that the weakened condition of the strange voles enabled a pathogenic organism to become invasive.
THE CLEARANCE OF INJECTED VASOPRESSIN FROM THE CIRCULATION AND ITS FATE IN THE BODY
Authors: GINSBURG M. , HELLER H.
Published: December 2008

1. The decrease of antidiuretic potency in the blood was studied in anaesthetized rats after the intravenous injection of vasopressin (100 mU/100 g) and was shown to follow an exponential course.

2. Removal of the kidneys retarded the rate of disappearance of injected vasopressin from the circulation, and so did tying of the coeliac and mesenteric arteries.

3. In rats in which the kidneys had been removed and the coeliac and mesenteric arteries had been tied, the disappearance of vasopressin was almost entirely prevented.

4. It was concluded that under the experimental conditions used, the extraction of vasopressin was almost complete after the passage of blood through the kidneys and the splanchnic vascular bed.

5. The kidneys accounted for about 50 % of the vasopressin cleared, and the splanchnic vascular area for at least 40 %.

6. The antidiuretic activity found in the urine after the intravenous injection of vasopressin into unanaesthetized rats was equivalent to 6·7 % of the dose administered.
THE ESTIMATION OF ACTH IN HUMAN PITUITARY TISSUE
Authors: TAYLOR N. R. W. , LORAINE J. A. , ROBERTSON H. A.
Published: December 2008

1. The ACTH concentration has been estimated in lyophilized pituitary tissue from five adults, seven infants and eight foetuses. Results are expressed in terms of the international standard. Adult pituitaries contain more ACTH than infantile glands, and infantile glands more than foetal ones.

2. ACTH activity was detected in foetal pituitaries at a period of gestation as early as 16 weeks.

3. The accuracy of the Sayers test was considerably improved when the time interval between hypophysectomy and assay was increased from 24 to 48 hr.
THE URINARY EXCRETION OF OESTROGENS AND PREGNANEDIOL AT THE END OF PREGNANCY, DURING LABOUR AND DURING THE EARLY PUERPERIUM
Authors: BRADSHAW T. E. T. , JESSOP W. J. E.
Published: December 2008

1. The excretion levels of oestrogen and pregnanediol have been followed in fourteen women during the last 3 weeks of pregnancy, during labour and during the first few days of the puerperium. Particular attention was paid to the period immediately before and after the onset of labour.

2. The amounts excreted during the last 3 weeks of pregnancy were high in all cases, but considerable variations were observed from day to day. During labour the values were usually lower, but there were frequent variations here also. The excretion fell to a low level within a few days following delivery.

3. There was a general tendency for the output of oestriol and total oestrogen to fall during the last 2 days before the onset of labour, and this fall was shown statistically to be highly significant on the day before onset and less significant on the previous day. However, in almost every case similar changes had been observed at earlier stages of pregnancy. In one woman the output was actually rising slightly when labour began.

4. The excretion of pregnanediol during the last 2 days of pregnancy was extremely variable, and no relationship between it and the onset of labour could be demonstrated.

5. The results obtained by other workers are discussed.
THE TOTAL AND DIFFERENTIAL CONCENTRATION OF RADIO-IODINE IN THYROID TISSUE AND ITS VARIATION WITH TIME, AS STUDIED BY AUTO-RADIOGRAPHY
Authors: NANDI S. , PODDAR R. K. , PYNE C. K.
Published: December 2008

1. Autoradiographs were made from thin thyroid sections of rats injected intraperitoneally with 20μc. 131I and killed at periods varying from 15 min to 16 days.

2. The concentrations of 131I in the thyroid sections were first deduced from G.M. counter measurements and then correlated with the average grain densities of their autoradiographs. From the observed grain densities in the colloid and cellular spaces of the thyroid follicles, the differential concentration of 131I in these sites was determined.

3. Each mm3 of thyroid tissue was found to fix about 0·1μc. in 15 min, 0·25μc. in 3 hr and 0·8μc. in 24 hr, out of the injected dose of 20μc. of 131I. The biological half-life of 131I in the thyroid was found to be 5·4 days.

4. From the knowledge of the total and differential concentrations of 131I, the partial volume of the colloid was calculated to be 66% of the whole thyroid volume, the rest being occupied by the cellular spaces. The latter was found to retain about half of the total 131I of the thyroid up to 15 min after the injection. But after 3 hr most of the 131I appeared in the colloid.
THE DEVELOPMENT WITH AGE OF HYPOTHALAMIC RESTRAINT UPON THE APPETITE OF THE RAT
Authors: KENNEDY G. C.
Published: December 2008

During a brief period after birth, while they are kept warm by the mother, young rats employ the major part of the food available to them for growth. Variations in milk supply lead to great differences in weaning weight. The amount of food the rats eat subsequently, and the rate at which they grow, depend upon the weight at weaning, that is, it is roughly exponential. In spite of their large calorie intake, heavy weanlings do not become obese, but their sexual development is markedly accelerated.

Lesions in the ventromedial nuclei of the hypothalamus of the adult rat are immediately followed by a twofold increase in the intake of food and the rapid development of obesity. Weanling rats, which already eat twice as much as adults in relation to their body weight, are unaffected by hypothalamic lesions until the age at which the intake of food normally falls. They resemble in this respect lactating adults, in whom the intake of food, already high, is not raised by hypothalamic lesions. At any age, the maximum calorie intake which has been recorded bears the same relation to body weight, about 45 kcal/100 g/day. The existence of this extra-hypothalamic restraint upon calorie intake probably explains the failure to saturate the capacity for growth, and so to produce obesity, in normal young rats. In a minority of weanling rats, hypothalamic lesions retard somatic growth, and in such rats obesity develops rapidly.
HISTOLOGICAL CHANGES IN THE ANTERIOR PITUITARY GLAND OF RATS INTOXICATED WITH BENZENE
Authors: IANNACCONE A. , CICCHELLA G.
Published: December 2008

Changes occurring in the rat anterior pituitary after daily subcutaneous injections of 0·5 ml. benzene/kg body weight for 22 days have been studied using histochemical methods.

The acidophil cells and the 'β' cells exhibit a closer relationship to the blood vessels and a reduction in their cytoplasmic granulation, associated with an increase in the chromidial substance and with enlarged and weakly stained nuclei. The most prominent change discernible in the 'δ' cells is the vesiculation of the cytoplasm, sometimes giving the typical appearance of 'signet-ring' castration cells.

These alterations have been interpreted as indicating an increased secretion of simple protein hormones (especially adrenocorticotrophic hormone) and thyrotrophic hormone by the rat pituitary, and a decreased discharge of follicle stimulating and luteinizing hormone.
AN INVESTIGATION OF THE PATHOGENESIS OF HASHIMOTO'S DISEASE BY THYROID TISSUE CULTURE
Authors: IRVINE W. J.
Published: December 2008

Human thyroid cells were grown in tissue culture in media containing normal human serum, Hashimoto serum, and rabbit sera containing antibodies to purified human thyroglobulin and to crude thyroid extract, respectively. The thyroid cells grew equally well in all media, with the exception of the rabbit serum containing antibodies to crude thyroid extract.

Intact thyroid cells obtained from tissue culture failed to fix Hashimoto antibodies in the presence of complement, whereas the constituents of disrupted thyroid cells gave a strongly positive complement-fixation test with Hashimoto serum. It is therefore suggested that the intact thyroid cell is impermeable to complement-fixing Hashimoto antibody.

The evidence afforded by the present work adds further weight to the belief that Hashimoto's disease may not be due to a simple auto-immunizing process consequent upon the interaction of thyroid antigen and the known circulating auto-antibodies. Evidence in support of an alternative hypothesis involving 'cell-bound' antibodies with disruption of the follicular basement membrane is discussed.
INCIDENCE OF SIMPLE GOITRE IN AREAS OF ENDEMIC FLUOROSIS
Authors: SIDDIQUI A. H.
Published: December 2008

The results of analyses of the mineral content of drinking water from three Indian villages with endemic fluorosis, surveyed for the incidence of thyroid enlargement, are reported.

With the possible exception of temporary thyroid enlargement encountered in pubertal subjects (type b, see text, p. 105), no relation was found between the incidence of endemic goitre and fluorine in the water supply.
A METHOD FOR THE ANALYSIS OF URINARY 17-HYDROXYCORTICOSTEROIDS
Authors: FEW J. D.
Published: December 2008

A method for the analysis of urinary 17-hydroxycorticosteroids is described. The urinary steroids are submitted, in situ, to sodium borohydride reduction, sodium periodate oxidation and mild alkaline hydrolysis. The generated 17-ketosteroids are separated by partition chromatography into 11-deoxy and 11-oxy fractions which are separately estimated by the Zimmermann reaction. By this method it is possible to estimate the urinary metabolites of cortisol without interference by corticosteroids not oxygenated at C-11.
HYPOPHYSECTOMY OF THE GOAT
Authors: COWIE A. T. , TINDAL J. S.
Published: December 2008

A technique for the surgical removal of the pituitary of the goat using the parapharyngeal approach is described and the after-care of the animals is discussed.
THE EFFECT OF 5-HYDROXYTRYPTAMINE ON PREGNANCY
Authors: LINDSAY D. , POULSON E. , ROBSON J. M.
Published: December 2008

The action of 5-hydroxytryptamine (5-HT) on pregnancy in mice has been investigated. Deleterious effects have been observed at all stages. In advanced pregnancy a single dose may kill the foetuses within half an hour.

The effect in early pregnancy can be antagonized by progesterone and by prolactin, as can the toxic effects of the drug on the experimental decidual reaction. In late pregnancy progesterone produces little, and prolactin no, reversal of the toxic action of 5-HT. It is suggested that in early pregnancy, 5-HT interferes with the hormonal mechanisms responsible for the maintenance of gestation, while later on its main toxic action is exerted directly on the uterine contents.
GENETIC AND HORMONAL INFLUENCES ON OVULATION AND IMPLANTATION IN ADULT MICE TREATED WITH GONADOTROPHINS
Authors: EDWARDS R. G. , WILSON E. D. , FOWLER RUTH E.
Published: December 2008

The innate oestrous cycle, the dose of hormone, and the strain of mouse used influence ovulation and implantation in adult mice treated with pregnant mares' serum (PMS) and human chorionic gonadotrophin (HCG). Almost all of the treated mice in some strains will mate, while those from other strains are less responsive.

Excess of hormone reduced the mating response and also suppressed ovulation through the formation of atretic corpora lutea and atretic follicles. Provided that the amount of hormone was not excessive, ovulation was induced in almost all mice of all strains irrespective of age, body weight, or stage of the oestrous cycle when treatment began. In one strain more eggs were recovered from females in metoestrus than from those in oestrus or dioestrus at the beginning of treatment, but this effect of the oestrous cycle was only found with low doses of PMS.

The proportion of mice with implanted embryos after treatment was influenced by the dose of hormone, strain differences, and the stage of the oestrous cycle when treatment began. This proportion was low after large amounts of PMS and HCG, and generally higher in strains of high natural fertility than in those of low fertility. Fewer of the mice in dioestrus, when injected with PMS, had implanted embryos than had those in oestrus or metoestrus. A strain of mice containing many acyclic females was least successful in implanting embryos.

The proportion of embryos that implanted decreased with increasing doses of hormone, apparently because of the increased competition between them for uterine sites.
IN VIVO STIMULATION BY ADRENOCORTICOTROPHIN (ACTH) OF RAT ADRENALS IN RELATION TO DIETARY FAT
Authors: SKOVSTED L. , FUNCH J. P. , DAM H.
Published: December 2008

Administration of ACTH did not change the amount or pattern of polyunsaturated fatty acids in the adrenals of rats given a fat-free diet, or diets containing hydrogenated or unhydrogenated peanut oil. The amounts in the adrenals of total polyunsaturated fatty acids, dienoic, tetraenoic, pentaenoic and hexaenoic acids decreased while trienoic acids increased in the adrenals of rats given the fat-free or hydrogenated peanut-oil diets. The secretion of corticosterone by the adrenal cortex following administration of ACTH in vivo was significantly reduced in rats maintained on a fat-free diet.
STEROIDS IN THE SEMEN OF DOGFISH (SQUALUS ACANTHIAS)
Authors: SIMPSON T. H. , WRIGHT R. S. , GOTTFRIED H.
Published: December 2008

11-Deoxycorticosterone has been found in surprisingly high concentration (ca. 500 μg./100 g.) in the semen of Squalus acanthias. Accompanying steroids are progesterone (8 μg./100 g.), androstenedione (2 μg./100 g.), dehydroepiandrosterone (2 μg./100 g.), pregnenolone (14 μg./100 g.), androsterone (< 5 μg./100 g.) and possibly aldosterone (< 1 μg./100 g.); three unidentified compounds were also detected. Only a small proportion (ca. 5%) of the 11-deoxycorticosterone is present in that portion of the semen which passes an ultrafilter. The remainder is either present as a sperm cell constituent or is bound to extracellular mucoids or proteins.
RESPONSE OF THE SUBMANDIBULAR GLAND OF THE CASTRATED MOUSE TO LOCAL AND SYSTEMIC ADMINISTRATION OF STEROIDS
Authors: BROWN-GRANT K. , TAYLOR W.
Published: December 2008

The effects of testosterone propionate (TP) and of 17α-ethyl-19 nor-testosterone (ENT) on the submandibular glands, levator ani muscles and seminal vesicles of castrated mice have been compared. ENT restores submandibular weight and histology about as well as TP but has less effect on the levator ani muscle and much less effect on the seminal vesicles. Both steroids can act directly on the submandibular gland. It is suggested that the effect on the gland may be an indication of the 'anabolic' rather than the 'androgenic' potency of the steroids, and the possible use of this response for the assay of 'anabolic' steroids is discussed.
THE EFFECT OF THYROID HORMONES IN VITRO ON THE OXYGEN CONSUMPTION OF TOAD TISSUES
Authors: THORNBURN C. C. , MATTY A. J.
Published: December 2008

Isolated tissues of the toad Bufo bufo were treated in vitro with thyroxine and triiodothyronine, and their oxygen uptake determined by conventional Warburg manometry. The respiration of the urinary bladder was stimulated by the hormones, and that of the kidney was reduced. Skin, heart, and muscle were affected to a lesser extent, the effect varying with dose and hormone.
THE INTRACELLULAR LOCALIZATION OF OESTROGEN IN RAT TISSUES
Authors: KING R. J. B. , GORDON J. , INMAN D. R.
Published: December 2008

The radioactive material in rat pituitary, liver and uterus 1 hr. after the s.c. injection of either 0·73 or 7·3 μg. [6,7-3H]oestradiol has been investigated. Oestrone and oestradiol were the only compounds detected in pituitary and uterus whereas at least six compounds were present in liver.

Cell fractionation studies have been carried out on anterior pituitary and liver from female rats which had received an injection of either 0·73 or 7·3 μg. [6,7-3H]oestradiol in vivo. Most of the tritium in the anterior pituitary was associated with the nuclear fraction whereas most of the tritium in the liver was in the soluble fraction. The uptake of [6,7-3H]oestradiol by the anterior pituitary reached a maximum ½-1 hr. after injection of the steroid and remained at this level for the next 3 hr. The intracellular distribution of this steroid at different times after injection suggests that the steroid passes into the cytoplasm and then into the nucleus.
SEQUENTIAL CHANGES IN RAT THYMUS AFTER THE SUBCUTANEOUS INJECTION OF CORTISOL
Authors: BELLAMY D. , JANSSENS P. A. , LEONARD RUTH A.
Published: December 2008

Several properties of the thymus were examined from the point of view of the mechanism of corticosteroid-induced involution. Involution, as measured by weight loss, proceeded for 3 days after a single subcutaneous injection of cortisol (3·0 mg./100 g. body wt.) into male rats. In thymus slices there was initially a transient inhibition of oxygen uptake. Other changes, namely a decreased concentration of ribonucleic acid and an increased release of protein from incubated slices, occurred later. There was no change in the degree of penetration of inulin, sucrose or sodium into incubated slices. It is thought that the results are consistent with the concept that cortisol sets in motion a set sequence of events, and that some of the changes are not dependent on the continued presence of hormone in the gland.
INTRA-UTERINE PRESSURE CHANGES DURING PREGNANCY AND PARTURITION IN RABBITS
Authors: PORTER D. G. , SCHOFIELD BRENDA M.
Published: December 2008

Small balloons attached to polyethylene tubing were inserted into either end of one uterine horn in rabbits on about the 22nd day of pregnancy. The tubing was threaded subcutaneously and brought out through an incision at the back of the neck; recordings of intra-uterine pressure changes were made up to and including parturition. There were no pressure changes which could be ascribed to contraction of the myometrium until an average of 31 hr. before delivery of the first foetus but there was considerable variation. Pressure waves recorded from the two balloons were often different in frequency and amplitude and were seldom synchronous. In none of the rabbits did one end of the horn develop 'parturient pressure' before the other and, in general, pressure at the ovarian end of the uterus was higher than at the cervical end. The rabbits could be divided into two groups: (I) those in which the onset of delivery was abrupt and preceding pressure waves were of low amplitude; (II) those in which the pressure waves increased gradually in intensity over several hours before delivery. Both the duration of delivery and the mortality rate of the foetuses were significantly greater in group II than in group I. The results in group I are consistent with the concept that in the normal rabbit parturition is initiated by a release of oxytocin. It is suggested that in group II oxytocin release failed to occur and that this failure was due to 'emotional stress' and possibly circulating adrenaline.
QUANTITATIVE ASSAY OF THE ACUTE HYPOTHALAMO-PITUITARY DEPRESSING EFFECT OF CORTICOSTEROIDS IN MAN
Authors: HEDNER L. P.
Published: December 2008

The reduction in plasma corticosteroid levels in man after administration of prednisolone, 16-methyleneprednisolone, triamcinolone and dexamethasone at four dose levels has been investigated. Homogeneous response variances and rectilinear log dose-response relationships were found for all of the preparations, thus providing a valid basis for a bioassay of the hypothalamus-pituitary depressing effect of these glucocorticosteroids. With respect to this effect, the relative potencies for the preparations in the order mentioned above were 1:0·64:1·63:17·5, and the index of precision for the log dose-response lines ranged from 0·19 to 0·39.

The requirements of the method are discussed and a comparison made with corresponding results obtained with other methods.
GENETIC VARIATION IN ADRENAL STRUCTURE: STRAIN DIFFERENCES IN QUANTITATIVE CHARACTERS
Authors: SHIRE J. G. M. , SPICKETT S. G.
Published: December 2008

Five quantitative parameters of adrenal structure have been measured for the adrenal glands of young adult mice of three inbred strains. Male and female A/Cam, CBA/FaCam and SF/Cam mice were compared in a first experiment and A and CBA males in a second. The findings in the two experiments were similar.

Significant strain differences, sex differences, and strain differences in sex difference, were found for the volume of the permanent cortex, and for the number of cells in it. There were strain differences in the volume of the cells of the zona fasciculata, and striking strain differences in the absolute and relative volume of the X-zone in female mice. Significant strain differences were also found in the volume of the medulla in males and females.

The findings are discussed in relation to the observed differences between the strains in adrenal weight, and in relation to the regulation of the size of the several zones of the cortex.
THE IMMUNOLOGICAL MEASUREMENT OF PREGNANT MARE SERUM GONADOTROPHIN
Authors: ALLEN W. R.
Published: December 2008

A quantitative haemagglutination—inhibition assay was used to measure pregnant mare serum gonadotrophin (PMSG) concentration in six Welsh Mountain pony mares and ten thoroughbred mares during early pregnancy. In both groups of animals PMSG was first detected in the serum between 35 and 41 days of gestation, the limit of sensitivity of the assay being 0·6 i.u. PMSG/ml. The levels rose sharply to reach a maximum at 55–60 days of gestation in the ponies and 60–65 days in the thoroughbreds. The highest concentrations recorded in both groups were 100–112 i.u. PMSG/ml., although one animal never produced more than 11 i.u./ml. The highest concentrations were found in the primiparous ponies. The rate of decline of the PMSG concentrations was not as great as the initial rate of increase, and in all animals PMSG had virtually disappeared from the serum by 120–130 days of gestation.

The haemagglutination-inhibition assay was evaluated as a pregnancy diagnosis test; 183 sera from 58 mares of various breeds between 41 and 87 days of gestation all gave a positive result, whereas 47 sera from non-pregnant mares, geldings and stallions gave uniformly negative results. An additional 64 sera from 23 mares between 88 and 110 days of gestation gave 62 positives, the two negative reactions being in a pony mare that showed exceptionally low concentrations of PMSG throughout pregnancy.
COLLABORATIVE STUDY OF ESTIMATES BY RADIOIMMUNOASSAY OF INSULIN CONCENTRATIONS IN PLASMA SAMPLES EXAMINED IN GROUPS OF FIVE OR SIX LABORATORIES
Authors: COTES P. MARY , MUSSETT MARJORIE V. , BERRYMAN I. , EKINS R. , GLOVER S. , HALES N. , HUNTER W. M. , LOWY CLARA , NEVILLE R. W. J. , SAMOLS E. , WOODWARD PATRICIA M.
Published: December 2008

Results of a collaborative study in which the insulin concentrations of a number of plasma samples were estimated in several laboratories are reported. They indicate that: (1) laboratories agreed on the ranking of plasma samples according to insulin content; (2) the reproducibility of replicate estimates obtained in the same assay usually overestimated the reproducibility of estimates made on different occasions; (3) values reported for the insulin concentration of the same plasma examined in each of a number of laboratories were likely to range from about one half to twice the inter-laboratory mean estimate.

Possible reasons for the variability of estimates are discussed.
THE ROLE OF THE OESTROGEN SECRETED BEFORE OESTRUS IN THE PREPARATION OF THE UTERUS FOR IMPLANTATION IN THE MOUSE
Authors: FINN C. A. , MARTIN L.
Published: December 2008

Priming of ovariectomized mice with 0·1 μg. oestradiol-17β for 3 days modified the subsequent cellular response of the uterus to oestrogen and progesterone. A single dose of oestradiol-17β (0·02 μg.), or progesterone (1 mg.), or of both hormones given simultaneously, stimulated mitosis in the epithelial cells of the endometrium (although not in the stromal cells). However, the same hormones administered to primed mice stimulated considerable stromal cell division and reduced epithelial mitosis. The maximal effect was found when both hormones were given on the 4th day after the end of priming. It is suggested that the priming of the uterus by oestrogen secreted by the ovary before mating is concerned in the abrupt change from epithelial to stromal cell division that occurs between days 3 and 4 of pregnancy, and is of importance in the sensitization of the uterus for implantation.
PITUITARIES OF SPAYED MICE OF DIFFERENT STRAINS: CYTOLOGY AND GONADOTROPHIN CONTENT
Authors: RANADIVE K. J. , KARANDE K. A.
Published: December 2008

The response to gonadectomy was shown to vary in two cancer-susceptible strains of mice, C3H/Jax and ICRC. In the strain ICRC, unlike strain C3H, adrenocortical response to gonadectomy was completely absent. The cytology of the pituitaries was studied in different age groups of these strains and the gonadotrophin content of the pituitaries after ovariectomy was determined.

A consistent increase in the number and size of the gonadotrophs accompanied by a rise in the storage of pituitary gonadotrophins was demonstrated after ovariectomy. These changes were much more pronounced and occurred earlier in strain C3H than in strain ICRC. The responses of strain ICRC closely resembled those of the cancer-resistant strain C57. It is suggested that the pituitary gonadotrophic response to gonadectomy is inadequate in strain ICRC which leads to the lack of responses from adrenal cortex and thus to the oontrol of breast cancer development.
STEROIDS OF A CHONDROSTEAN: IDENTIFICATION OF INTERRENAL TISSUE IN THE AMERICAN ATLANTIC STURGEON, ACIPENSER OXYRHYNCHUS MITCHILL, BY HISTOLOGICAL AND HISTOCHEMICAL METHODS
Authors: IDLER D. R. , O'HALLORAN M. J.
Published: December 2008

Yellow bodies scattered throughout the kidney tissue and posterior cardinal veins of the American Atlantic sturgeon Acipenser oxyrhynchus Mitchill were examined by histological and histochemical methods. Their histology resembled that of interrenal tissue, rather than that of corpuscles of Stannius.

The tissue was assayed histochemically for 3β-, 3α-, 11β-, 20β- and 20α-hydroxysteroid dehydrogenase (HSD) activity. Intense 3β-HSD activity was observed in the yellow bodies when dehydroepiandrosterone and pregnenolone were employed as substrates. Very weak 3α-HSD activity was observed with androsterone as a substrate. No 11β-HSD activity was observed with cortisol and corticosterone as substrates, and no 20α- or 20β-HSD activity when 20α- or 20β-hydroxyprogesterone respectively were employed as substrates.

These studies suggest that the yellow bodies found in the posterior cardinal veins and kidney tissue of A. oxyrhynchus Mitchill are true interrenal tissue.
STEROIDS OF A CHONDROSTEAN: IN-VITRO STEROIDOGENESIS IN YELLOW BODIES ISOLATED FROM KIDNEYS AND ALONG THE POSTERIOR CARDINAL VEINS OF THE AMERICAN ATLANTIC STURGEON, ACIPENSER OXYRHYNCHUS MITCHILL
Authors: IDLER D. R. , SANGALANG G. B.
Published: December 2008

This report presents direct evidence for steroidogenesis by chondrostean tissue. The enzymes necessary for steroid transformation and cleavage of the cholesterol sidechain are present in yellow bodies isolated from the kidneys and along the posterior cardinal veins of the Atlantic sturgeon, Acipenser oxyrhynchus Mitchill.

Yellow bodies of the Atlantic sturgeon were incubated with [16-3H]pregnenolone plus [4-14C]progesterone in vitro and cortisol was formed in yields of 54·3 and 55·1% of the 3H and 14C precursor activities, respectively. Double-labelled cortisone, corticosterone, 11-deoxycortisol, 17α-hydroxyprogesterone and progesterone were isolated as transformation products but in relatively much lower yields. 11-Deoxycorticosterone, aldosterone and 1α-hydroxycorticosterone were not detected. When yellow bodies were incubated with [7-3H]cholesterol the following labelled transformation products were isolated: pregnenolone (0·43%), progesterone (0·091%), 17α-hydroxyprogesterone (0·023%), cortisol (0·061%), cortisone (0·004%), corticosterone (0·001%) and 11-deoxycortisol (0·047%). Again, 11-deoxycorticosterone, aldosterone, and 1α-hydroxycorticosterone were not detectable. All steroid products were identified by their isopolarity with authentic steroids by repeated chromatography, and by recrystallizations of free steroids and/or derivatives, after addition of authentic radio-inert steroids, to constant 3H:14C isotope ratios.
THE EFFECTS OF PROLONGED ADMINISTRATION OF CORTISOL ON THE SKIN OF SHEEP ON DIFFERENT PLANES OF NUTRITION
Authors: CHAPMAN R. E. , BASSETT J. M.
Published: December 2008

The effects of prolonged administration of cortisol on epithelial and dermal tissues were examined in three groups of non-pregnant ewes with different food intakes. The changes observed depended on the degree of increase in plasma cortisol and in some instances on the amount of food eaten.

Successive increases in plasma cortisol up to about 3 μg/100 ml progressively inhibited the tissues in the skin of sheep on restricted food intakes, but not those in the skin of sheep which increased their intakes. In the latter, a slight increase in plasma cortisol to about 1 μg/100 ml stimulated wool production and fibre-length growth rate. Moderate increase to about 2 μg/100 ml produced temporary enlargement of sweat glands, dilatation of capillaries and an increase in the number of dermal mast cells.

Regardless of the amount of food eaten, retrogression of all epithelial and dermal components was maximal when plasma cortisol remained above about 3 μg/100 ml. Follicle inactivation and cessation of fibre-growth occurred with the formation of brush-ends on the fibres. The retrogression of the tissues occurred in spite of increased blood glucose concentrations, indicating that cortisol depressed the utilization of glucose by the skin. Keratinization of the epidermis was altered and was possibly hastened.

The rates of recovery of the different tissues after cessation of cortisol administration were variable. Follicle regeneration and commencement of fibre regrowth were the slowest. The epidermis of the sheep on restricted food intake showed an unusual thickening.

Cortisol acetate applied topically to the skin of other sheep produced changes consistent with those induced by injected cortisol.
A COMPARISON BETWEEN THE UPTAKE OF TECHNETIUM-99m AND IODINE-131 BY THE THYROID GLAND
Authors: McGILL P. E. , HARDEN R. McG. , ROBERTSON I. W. K. , SHIMMINS J.
Published: December 2008

The uptake by the thyroid gland of 99mTc has been measured 20 min after administration of a tracer dose in seven normal controls and 52 patients with thyroid disease. The mean uptake in normal subjects was 0·96 ± 0·17% of the dose, in patients with non-toxic goitre 2·87 ± 0·39% of the dose, in thyrotoxic patients 16·7 ± 1·9% of the dose and in hypothyroid patients 1·94±0·27% of the dose. The uptake of 131I administered simultaneously with 99mTc was measured after 20 min and 5 h. The 20 min 99mTc uptake correlated well with the 20 min 131I uptake, but less well with the 131I uptake at 5 h. As a test of thyroid function, 99mTc has the advantages of low radiation dose and less inconvenience for the patient if thyroid scanning is also required. However, because of the high background activity in the neck it is necessary to use an isotope scanning technique.
ADRENAL BIOGENESIS IN VIVO OF ANDROGENS AND CORTISOL IN THE GUINEA-PIG USING A CONTINUOUS INFUSION TECHNIQUE
Authors: DESHPANDE N. , CARSON PAMELA , HARLEY SHEILA
Published: December 2008

An in-situ continuous infusion technique was used to study the biogenesis of androgens and cortisol in the guinea-pig adrenal gland after the infusion of 3H- and 14C-labelled precursors of these compounds. Pregnenolone was converted to 17α-hydroxypregnenolone, progesterone, 17α-hydroxyprogesterone and cortisol. The results of infusion of a combined dose of [3H]17α-hydroxypregnenolone and [14C]progesterone indicated that the major pathway to cortisol is via 17α-hydroxypregnenolone. No conclusive proof could be obtained regarding synthesis of dehydroepiandrosterone or androst-4-ene-3,17-dione. The only androgen detected in the guinea-pig adrenal venous blood was 11β-hydroxyandrost-4-ene-3,17-dione. The major and minor biosynthetic pathways involved in the synthesis of these hormones are discussed.
EFFECT OF TESTOSTERONE ON PROTEIN SYNTHESIS AND CONTRACTILITY OF THE LEVATOR ANI MUSCLE OF THE RAT
Authors: BUREŠOVÁ M. , GUTMANN E.
Published: December 2008

The effects of testosterone on the incorporation of leucine and uridine into the proteins and RNA in vitro and on contractile properties of the levator ani muscle were studied.

After long-term preincubation of the muscle with testosterone, incorporation of the labelled precursors into RNA and proteins of the muscle increased by 33 and 78% respectively. No previous treatment in vivo was necessary to show this effect of testosterone.

The increase of incorporation of the labelled precursors into RNA and proteins, tested after preincubation with testosterone, was more pronounced after castration, and was 61 and 134% respectively. The incorporation of labelled precursors into RNA and proteins of the diaphragm muscle of the rat was not affected by preincubation with testosterone in vitro.

Long-term application of testosterone in vitro resulted in a decrease of contraction time and latency period of the levator ani muscle.
FATE OF ANDROSTA-4,16-DIEN-3-ONE AND THE ORIGIN OF 3α-HYDROXY-5α-ANDROST-16-ENE IN MAN
Authors: BROOKSBANK B. W. L. , WILSON D. A. A. , MacSWEENEY D. A.
Published: December 2008

The metabolic clearance rate (MCR) of androsta-4,16-dien-3-one (androstadienone) and the cumulative specific activity (CSA) of urinary 3α-hydroxy-5α-androst-16-ene (androstenol) were measured in two healthy men and in one healthy woman after single intravenous injections of 4-[14C]- or 7α-[3H]androstadienone. Approximate plasma production rates, calculated from the MCR and values for the endogenous androstadienone concentration in plasma pools from six male and six female donors (0·984 and 0·366 μg/l respectively), were 975 and 1341 μg/24 h for the two men and 456 μg/24 h for the woman. The 'production rates' of androstadienone calculated from the CSA of urinary androstenol were 5210, 3730 and 1070 μg/24 h respectively. It follows that urinary androstenol is not uniquely derived from circulating androstadienone and it is concluded that both steroids are secretory products. Alternative sources and precursors of urinary androstenol are discussed.

Secretion of radioisotope in the sweat appeared to occur predominantly in the axillae, but was quantitatively no greater than in previous experiments with labelled progesterone and 5-pregnenolone.
KINETIC ASPECTS OF THE DEPRESSION OF 131IODIDE CONCENTRATION BY THYROTROPHIN IN THYROID TISSUE IN VITRO
Authors: MANLEY S. W. , BOURKE J. R. , HAWKER R. W.
Published: December 2008

The changes in the kinetics of 131I131I− accumulation accompanying the thyrotrophin (TSH)-induced decrease in the tissue/medium concentration ratio (T*/M*) in propylthiouracil-blocked guinea-pig thyroid slices in vitro have been investigated. 131I− was eluted in serial 2 ml fractions from prelabelled 10 mg thyroid slices incubated for 10 h with TSH. Retrapping of 131I− from the extrafollicular space was abolished by including ClO4− in the elution medium. In the presence of ClO4−, departures from 1st order kinetics were detected by the analysis of regression of successive estimates of instantaneous exit rate, though not by the analysis of regression of logeTt*/T0*. It was predicted that initial exit data would be more representative of exit rates under equilibrium conditions. TSH gave increases in the fractional exit rate (Ktm) of similar order to those required to account for the decrease in T*/M*.

The data support the hypothesis that an increase in 131I− exit rate mediates the decrease in T*/M* induced by TSH.
BLOOD FLOW CHANGES IN THE PITUITARY NEURAL LOBE OF THE RABBIT ASSOCIATED WITH NEUROHYPOPHYSIAL HORMONE-RELEASING STIMULI
Authors: SOORIYAMOORTHY T. , LIVINGSTON A.
Published: December 2008

Blood flow rates in the posterior pituitary glands of rabbits were calculated by measuring the clearance of locally deposited 133Xe in saline detected by an externally located probe. These studies indicated that intraarterial injection of CaCl2 and central stimulation of a vagus (both hormone-releasing stimuli) caused a significant rise in blood flow, whilst during haemorrhage, also a release stimulus, the blood flow in the posterior pituitary was maintained. Pretreatment with atropine abolished the increase seen with CaCl2 and vagal stimulation and caused a significant fall in blood flow after haemorrhage. Parasympathomimetic drugs caused an increase in the flow which was also atropine-sensitive; sympathomimetic drugs and sympathetic blocking drugs caused no alteration in blood flow.

These results indicate that there is a local increase in blood flow in the posterior pituitary which is associated with hormone-releasing stimuli and which is cholinergically mediated.
CHANGES IN THE APPEARANCE OF HYPOTHALAMO-NEUROHYPOPHYSIAL NEUROSECRETORY GRANULES ASSOCIATED WITH THEIR MATURATION
Authors: CANNATA M. A. , MORRIS J. F.
Published: December 2008

The appearance of neurosecretory granules (NSG) in different parts of the hypothalamo-neurohypophysial system (paraventricular and supraoptic neurosecretory neurones and their processes within the hypothalamus and in the neural lobe) of the rat was studied after fixation at different pH's (5·0, 6·0, 7·0 or 8·0) using a triple-aldehyde mixture followed by osmium tetroxide. Differences between the areas studied were most marked at pH 8·0. At this pH a significantly greater proportion of granules retained an electron-dense core within the perikarya and adjacent processes than within the neural lobe, where only 5% of all granules remained dense-cored. At pH 8·0 comparison of NSG in paraventricular and supraoptic areas showed that a significantly higher proportion of granules remained dense-cored in the paraventricular region. This difference was particularly marked in the neurosecretory processes.

The difference in response to fixation at pH 8·0 between hypothalamus and neural lobe may reflect changes in the nature of the granule resulting from 'maturation'. If so, maturation starts within the perikaryon and proceeds as the granules pass down the axons to the neural lobe, where very few remain immature.

The differences between paraventricular and supraoptic regions might be explained as a result of faster maturation of granules containing vasopressin than those containing oxytocin.
PLASMA CORTICOSTERONE LEVELS DURING PREGNANCY IN THE MOUSE: THE RELATIVE CONTRIBUTIONS OF THE ADRENAL GLANDS AND FOETO-PLACENTAL UNITS
Authors: BARLOW SUSAN M. , MORRISON P. J. , SULLIVAN F. M.
Published: December 2008

Plasma corticosterone levels were measured throughout pregnancy and on the first day post partum in the mouse. During the first half of pregnancy plasma corticosterone levels rose from the non-pregnant value of 2·3 μg/100ml to 15·2 μg/100 ml on day 10. During the second half of pregnancy there was a sharp rise, levels reaching a peak of 138·3 μg/100ml on day 16. Following parturition there was a rapid fall to 18·3 μg/100 ml on the morning of the first day post partum. Adrenalectomy on day 15 resulted in an 80% fall in plasma corticosterone levels indicating that most of the steroid was of adrenal origin. The remaining portion of the corticosterone was found to be of foeto-placental origin, and in the chronically adrenalectomized animal this source was capable of maintaining high blood levels of corticosterone (67 μg/100 ml). The foeto-placental unit also provides the main secretory stimulus to the adrenal gland, but the mechanism by which it does this is not understood.
RADIOIMMUNOASSAY OF OESTRONE, OESTRADIOL-17α AND -17β IN BOVINE PLASMA DURING THE OESTROUS CYCLE AND LAST STAGES OF PREGNANCY
Authors: DOBSON HILARY , DEAN P. D. G.
Published: December 2008

Specific antibodies were raised against 6-(O-carboxymethyl)oxime—bovine serum albumin derivatives of oestrone, oestradiol-17α and -17β for use in radioimmunoassays to measure each unconjugated oestrogen in peripheral plasma during the bovine oestrous cycle and the last stages of pregnancy. In non-pregnant cows the concentration of oestradiol-17β increased from very low values of 5 pg/ml to 14 pg/ml at oestrus. Oestrone showed little cyclic variation with an average concentration of 4 pg/ml, whereas oestradiol-17α varied inconsistently at much higher levels between 20 and 30 pg/ml.

An increase in the concentration of each oestrogen occurred in the last 14 days of pregnancy with a rapid decrease around parturition. Oestradiol-17β increased from 400 pg/ml on Day — 14 to 1000 pg/ml on Day — 1 with values of 300 pg/ml at parturition. Similar values for oestradiol-17α were 400, 800 and 500 pg/ml with a further decrease to 300 pg/ml, 1 day post partum. Higher concentrations for oestrone were observed: 900 pg/ml on Day — 14, 2800 pg/ml Day — 1, decreasing rapidly to 500 pg/ml on the day of parturition.
EFFECT OF EXERCISE ON THE SECRETION AND METABOLISM OF CORTISOL IN MAN
Authors: FEW J. D.
Published: December 2008

Concentration and specific activity of plasma cortisol were measured for 4 h after the intravenous injection of 10 μCi [1,2-3H]cortisol into 14 normal men. Of these subjects four were resting controls; four exercised at a high work load for 1 h; four exercised at a low work load for 1 h and two received infusions of unlabelled cortisol, all beginning 1 h after the administration of [1,2-3H]cortisol.

In the high work load group plasma cortisol had increased by 12·2 ± 6·3 μg/100 ml at the 60th minute of exercise. In this group the half-life of [3H]cortisol was 31·5 ± 5·3 (s.d.) min in contrast to 74·5 ± 8·3 min for the resting controls (P < 0·001).

In the light exercise group plasma cortisol concentration tended to fall, but due to large intersubject differences this was not statistically significant. In this group the half life (t½) of [3H]cortisol was 43·8 ± 3·9 min which was also significantly different from that of the resting controls (P < 0·001).

Specific activity of plasma cortisol fell rapidly (mean t½ = 15 min) during 1 h of heavy exercise, and continued to fall to a nadir 10–30 min after exercise had ceased, finally reaching a value some 60% above the nadir 1·5–2·0 h after exercise had ceased. A similar, although exaggerated, pattern was observed in the two resting subjects into whom 5 and 4 mg respectively, of unlabelled cortisol were infused. In contrast, in the light exercise group cortisol specific activity changed only slowly (mean t½ = 151 min) but continued to fall after exercise.

In the light exercise group, during the latter part of exercise and during the first hour after exercise, the ratio [3H]cortisone: [3H]cortisol in plasma was significantly higher than the corresponding values for the resting group (P < 0·05). Even higher values for this ratio were obtained for some of the heavy exercise subjects but due to wide scatter the group was not statistically significantly different from the resting group.

These results suggest that exercise itself increases the rate of uptake of cortisol by peripheral tissues and that when the work load exceeds a critical level stimulation of the adrenal cortex results in a massive secretion of cortisol which is sufficient to raise the plasma level which in turn promotes further ingress of cortisol into the tissues. After exercise at a high work load a return of cortisol from the tissues to the plasma can be detected.
EFFECTS OF POSTPUBERTAL OESTROGEN INJECTIONS ON MITOTIC ACTIVITY OF VAGINAL AND UTERINE EPITHELIAL CELLS IN MICE TREATED NEONATALLY WITH OESTROGEN
Authors: MORI TAKAO
Published: December 2008

Cell cycles of vaginal and uterine epithelial cells were studied using [3H]thymidine autoradiography in adult ovariectomized mice given oestrogen injections neonatally. The mice were in a 'persistent-oestrous' state, showing ovary-independent, continued proliferation and cornification of the vaginal epithelium. The duration of different stages of the cell cycle could not be assessed in such mice, since the percentage of labelled mitoses failed to rise to 100%. In neonatally oestrogenized, adult mice the vaginal epithelium appeared to contain a mixed population of cells. After an oestrogen injection, almost all mitoses of vaginal epithelial cells became labelled, with a generation time of about 17 h. By contrast, the generation time was about 15 h in vaginal epithelial cells of ovariectomized 'normal' mice injected with oestrogen when adult. The uterine epithelium of neonatally oestrogenized, ovariectomized mice also consisted of a mixed population of cells.

A single oestrogen injection produced an increase in both the mitotic rate and cell number in the vaginal and uterine epithelium of ovariectomized 'normal' adults but not in neonatally oestrogenized, ovariectomized adults. These studies show that in mice given oestrogen neonatally, uterine and vaginal epithelial cells were not responsive to oestrogen or at least less sensitive to oestrogen than ovariectomized 'normal' controls.