bluuebunny/crossref_metadata_2025 huggingface dataset:
ACTION OF OESTRADIOL-17β AND CYCLIC AMP ON THE SYNTHESIS OF RNA, PHOSPHOPROTEINS AND PHOSPHOLIPIDS IN THE UTERUS OF OVARIECTOMIZED RATS IN VITRO
Authors: RAO K. N. , TALWAR G. P.
Published: December 2008

Administration of oestradiol-17β to ovariectomized rats increases the incorporation of [32P]orthophosphate into RNA, phosphoproteins and phospholipids of the uterus. Uteri taken from the ovariectomized rats pretreated with oestradiol for 1 h in vivo continued to manifest enhanced ability to incorporate 32P into RNA, phospholipids and phosphoproteins when tested in vitro. However, when oestradiol was added directly to the incubation medium, it failed to stimulate to the same extent the incorporation of [32P]orthophosphate into RNA and phosphoproteins in excised uteri from ovariectomized rats. An increase in the incorporation of 32P into phospholipids was obtained only after prolonged incubation of the excised uteri in the medium containing oestradiol.

A number of experimental approaches has been tried to reproduce more completely the in-vivo actions of oestradiol on the rat uterus in vitro. Supplementation of the medium with hormones such as insulin, progesterone and biogenic amines like adrenaline, histamine and serotonin besides oestradiol was not sufficient to attain the metabolic capacities of the uterus from animals primed with oestradiol in vivo. Oestrone was not effective. The presence of tissues such as liver, parametrial fat, adrenal glands or anterior pituitary in the incubation medium did not modify the lack of full response of ovariectomized rat uteri to oestradiol in vitro.

Studies were also extended to uteri incubated in the peritoneal cavity of ovariectomized rats instead of in synthetic media. Moreover the uteri of rats in pro-oestrus and dioestrus were also tested in vitro for their lack of full invivo-like response to oestradiol.

Cyclic 3′,5′-AMP and AMP stimulated in vitro the incorporation of [32P]orthophosphate into RNA but not into phosphoproteins and phospholipids.

Results are discussed and arguments made for the lesion possibly preventing the full development of the uterotropic action of the hormone in vitro, even though limited effects of the hormone were obtained.
LUTEINIZING HORMONE RELEASING FACTOR IN ULTRAFILTRATES OF BLOOD COLLECTED FROM THE PITUITARY STALK OF OVARIECTOMIZED RATS AND RATS SUBJECTED TO ELECTRICAL STIMULATION OF THE PREOPTIC AREA
Authors: BURGER H. G. , FINK G. , LEE V. W. K.
Published: December 2008

The presence of luteinizing hormone releasing factor (LH-RF) activity was investigated in pituitary stalk and systemic blood collected from rats ovariectomized at least 3 weeks previously, and in stalk blood from male rats in which electrodes had been implanted in the medial preoptic area of the brain. Most of the assayable luteinizing hormone (LH) present in the blood samples was eliminated by acid-ethanol extraction followed by ultrafiltration. The ultrafiltrates were injected into ovariectomized rats treated with oestrogen and progesterone, and increments in the concentration of LH in the sera of these animals, estimated by radioimmunoassay, were taken as an indication that the filtrate was able to release LH from the anterior pituitary gland. The ultrafiltrates of both the stalk and systemic plasma from the ovariectomized rats exhibited LH-RF activity as did the ultrafiltrates of blood collected from the pituitary stalk of the male rats during electrical stimulation of the preoptic area; stalk blood collected from these animals before the current was applied appeared to be inactive. The LH-RF activity of the ultrafiltrates of systemic and pituitary stalk plasma taken from ovariectomized rats was similar, and, therefore, the possibility is raised that the response of the pituitary glands in ovariectomized rats treated with oestrogen and progesterone is of an all or none type. The presence of appreciable quantities of LH-RF in the systemic plasma of ovariectomized rats may explain the discrepancy between bioassay and immunoassay estimates of LH in the plasma of these animals. The rapid increase in the concentration of serum LH and in the LH-RF activity of pituitary stalk plasma which followed stimulation of the preoptic area suggests that this region of the brain may be important in the control of the secretion of LH in the male as well as in the female animal.
THE ROLE OF THE STEROID-SENSITIVE CATION-DEPENDENT ATPASE IN HUMAN PROSTATIC TISSUE
Authors: FARNSWORTH W. E.
Published: December 2008

The purposes of this study were: (1) to determine if a (Na+ + K+)-dependent, ouabain-sensitive, androgen-responsive ATPase is present in the microsomal fraction of the human prostate as it is in the rat ventral prostate; (2) to determine the degree and nature of interaction and interdependence of the ATPase with the steroid-binding and steroid-metabolizing activities of the prostate and, also, with the histological characteristics of the gland. The results indicate that ATPase which shows particular responsiveness to 5α-dihydrotestosterone, 5α-androstane-3α,17β-diol and dehydroepiandrosterone is present. The microsomes, which contain this enzymic activity, show relatively high affinity for the active steroids and for oestradiol-17β. The intrinsic steroid-sensitive, cation-dependent ATPase activity varies widely from gland to gland in parallel with the steroid binding and 3α-hydroxysteroid dehydrogenase activity. In comparisons of the enzymatic complements of glands with different histological features, the concentration of 4-en-3-oxosteroid-5α-reductase activity in tissue showing predominantly epithelial hyperplasia was greater than that in normal or carcinomatous glands or glands with stromal hypertrophy. The possible role of the ATPase as a mediator of hormonal stimulation, and the implications of the findings to an understanding of the development of benign prostatic hypertrophy, are discussed.
BLOOD LEVELS OF OXYTOCIN IN THE FEMALE GOAT DURING COITUS AND IN RESPONSE TO STIMULI ASSOCIATED WITH MATING
Authors: McNEILLY A. S. , DUCKER H. ALISON
Published: December 2008

Blood oxytocin was assayed on the lactating guinea-pig mammary gland. Thirty-six series of serial jugular blood samples were collected from 33 oestrous female goats during normal mating and the transient appearance of oxytocin (2 to 190 μu./ml plasma) was detected in 28 of the series. Coitus did not appear to be a major stimulus for the release of oxytocin. However, oxytocin release occurred in many experiments shortly before coitus when the male was present and continued after coitus for varying times up to 16 min after the male had left the mating room. Oxytocin (9–150 μu./ml plasma) was also released during simulated mating in all six experiments carried out in six dioestrous female goats.

In a further 16 oestrous female goats, oxytocin release (7–73 μu./ml plasma) occurred in response to individual exteroceptive stimuli associated with mating and these stimuli could be classified in descending order of effectiveness in causing oxytocin release as follows: presence of another goat > smell of the male > sound of the male > sight of the male.

The results indicate that oxytocin release occurs in oestrous female goats in response to a complex of stimuli occurring during mating and that physical stimuli associated with coitus are only important in causing oxytocin release during simulated mating in dioestrous female goats.
VARIATIONS IN THE BLOOD VOLUME OF THE NEURAL AND ANTERIOR LOBES OF THE PITUITARY OF THE RAT ASSOCIATED WITH NEUROHYPOPHYSIAL HORMONE-RELEASING STIMULI
Authors: SOORIYAMOORTHY T. , LIVINGSTON A.
Published: December 2008

Measurements of the blood volume of the neural and anterior lobes of the pituitaries of rats using 51Cr-labelled erythrocytes indicated that all stimuli examined which released neurohypophysial hormones also led to a significant increase in neural lobe blood volume. The blood volume of the anterior lobe was not altered by any of these stimuli.

Experiments with parasympathetic blocking drugs indicated that this mechanism involved cholinergic pathways, a conclusion which was supported by the results of experiments with parasympathomimetic drugs. Sympathetic blockers and sympathomimetic drugs produced no appreciable effects on the blood volume responses.

It is concluded that vasodilation occurs in the neural lobe of the rat associated with stimuli which are known to release neurohypophysial hormones and that this vasodilation involves cholinergic mechanisms but that these pathways may not be identical with those responsible for hormone release.
THE SODIUM AND POTASSIUM CONCENTRATIONS IN THE UTERINE FLUID OF THE RAT AT THE TIME OF IMPLANTATION
Authors: CLEMETSON C. A. B. , KIM J. K. , MALLIKARJUNESWARA V. R. , WILDS J. H.
Published: December 2008

Rat uterine fluid Na+ and K+ concentrations were calculated from the ratio of the Na+ and K+ concentrations in uterine washings, on the assumption that the sum of Na+ and K+ (mequiv./l) is the same in blood serum and in uterine fluid. Uterine fluid volumes were likewise calculated from the total quantity of Na+ and K+ washed out of the uterine horn.

The mean uterine fluid volume was 7·6 μl per horn and the mean potassium concentration was 45·8 mequiv./l on day 6 of normal pregnancy. Both oophorectomy alone on day 2 and oophorectomy followed by daily injections of progesterone, cause a marked reduction of the uterine fluid volume on day 6 of pregnancy. Oophorectomy on day 2 caused a significant reduction in the uterine fluid K+ concentration. Administration of high and low doses of progesterone after oophorectomy on day 2 of pregnancy resulted in uterine fluid potassium concentrations higher and lower, respectively, than the normal day 6 fluid.

It is postulated that a high uterine fluid K+ concentration is essential for blastocyst-endometrial contact preceding implantation and that this may be significant with regard to certain types of delayed implantation.
A COMPARISON OF THE COMPETITIVE PROTEIN-BINDING ASSAY AND RADIOIMMUNOASSAY FOR PLASMA PROGESTERONE DURING THE NORMAL MENSTRUAL CYCLE
Authors: MORGAN CHRISTINE A. , COOKE I. D.
Published: December 2008

A protein-binding assay for plasma progesterone using 2% aqueous chick plasma as the binding solution is described. Details of specifications for petroleum spirit to extract the plasma are given, no chromatographic step being employed. Bound and free steroid are separated by Florisil. The system will assay plasma progesterone at a concentration of 2·0 ng/ml; other reliability data are evaluated. One technician can assay 12 duplicate plasma samples per day.

The radioimmunoassay method has utilized two antisera, the first, antiprogesterone-20-0-carboxymethyl-oxime—bovine serum albumin at a dilution of 1 in 3000, the second, anti-progesterone-11-succinyl—bovine serum albumin at a dilution of 1 in 10000. Bound and free steroid are separated by dextran—charcoal suspension. The system will assay plasma progesterone at a concentration of 1·0 ng/ml. One technician can assay 24 duplicate plasma samples per day.

There is a good correlation between results obtained by both competitive protein-binding (CPB) and radioimmunoassay (RIA) methods. Both methods have a place in estimating the large numbers of serial samples required in the study of physiological situations, although the RIA method will probably supersede the CPB because of its robustness and greater output.
REGULATION OF THE PERMEABILITY TO WATER IN TOAD URINARY BLADDER: THE EFFECT OF COPPER
Authors: PARISI MARIO , PICCINNI ZULEMA F.
Published: December 2008

The effect of Cu2+ in concentrations from 1 × 10−7 to 1 × 10−4 mol/1 on water movement across the toad urinary bladder in vitro was studied. Although Cu2+ did not alter the permeability to water by itself, it strongly inhibited the hydrosmotic response induced by oxytocin and theophylline. This effect was present only when the ion was added to the serosal side. The observed inhibition was not completely reversible even at the lower Cu2+ concentrations. No interaction of Cu2+ with cyclic AMP was observed. However, a reversible inhibitory effect of the ion on the hydrosmotic response induced by increasing tonicity of the medium was demonstrated. In this case Cu2+ was effective from both sides. It is concluded that Cu2+ has two effects: (1) a non-reversible action on the cyclase system, inhibiting the responses to oxytocin and theophylline; (2) a reversible action on the 'osmosensitive mechanism', inhibiting the response induced by increasing tonicity.
THE EFFECTS OF OESTROGEN ON THE CELL CYCLE IN EPITHELIAL AND CONNECTIVE TISSUES OF THE MOUSE UTERUS
Authors: DAS R. M.
Published: December 2008

The duration of stages of the cell cycle in the uterine epithelial and stromal tissues of ovariectomized mice was estimated by the labelled mitosis method. In untreated animals the mean duration of the S phase (DNA synthesis) was 10·5 h in the glandular and luminal epithelium. Oestrogen treatment shortened it to 6 h in both tissues. In the endometrial stroma of progesterone-treated mice the duration of S was 8 h; when oestrogen was given it increased slightly. The generation times estimated under steady-state conditions were 270,156 and 383 h respectively in the lumen, glands and stroma of untreated mice. After oestrogen stimulation the responses became highly synchronized.
A SOLID PHASE RADIOIMMUNOASSAY FOR OVINE AND CAPRINE PROLACTIN USING SEPHAROSE 6B: ITS APPLICATION TO THE MEASUREMENT OF CIRCULATING LEVELS OF PROLACTIN BEFORE AND DURING PARTURITION IN THE GOAT
Authors: HART I. C.
Published: December 2008

A rapid solid phase radioimmunoassay for ovine and caprine prolactin is described utilizing antibodies chemically bound to Sepharose 6B. Prolactin was measured in blood samples taken from goats at varying intervals before the onset of the first stage of labour. The concentration of prolactin rose 5–35 h before parturition to a level 2·6–4·5 times the lowest concentration found earlier in gestation. The results of serial samples taken during the first and second stages of labour indicate that the intense uterine contractions associated with the expulsion of the kid are associated with a large increase in the level of prolactin in the blood.
INFLUENCE OF AGE ON THE RELEASE OF LUTEINIZING HORMONE INDUCED BY OESTROGEN AND PROGESTERONE IN IMMATURE RATS
Authors: CALIGARIS L. , ASTRADA J. J. , TALEISNIK S.
Published: December 2008

In immature female rats serum luteinizing hormone (LH) concentration, as measured by radioimmunoassay, was found to be higher at 10 or 15 days of age than thereafter. Animals ovariectomized soon after birth or at 5 days of age showed a significant rise in serum LH levels 10 days later.

A positive feedback effect on LH secretion was observed on the day following a single injection of oestradiol benzoate (OB) in 28-day-old rats but not in younger animals. However, in animals primed with OB a second dose of OB 2 days later resulted in a significant rise in serum LH levels even in rats of 22 days of age.

Progesterone (1 mg) injected 3 days after the injection of a single dose of OB induced, a few hours later, a significant rise in serum LH concentration. This effect was observed from the 22nd day of age but not in younger animals. The magnitude of the response to progesterone, as revealed by the serum LH levels, sharply decreased at the time of puberty.

It is concluded that the mechanisms responsible for the tonic release of LH are ready to function at the time of birth or shortly thereafter, while those involved in the phasic release mature around 22 days of age.
THE METABOLIC CLEARANCE RATE AND PRODUCTION RATE OF PROGESTERONE AND THE CONVERSION OF PROGESTERONE TO 20α-HYDROXYPREGN-4-EN-3-ONE IN THE SHEEP
Authors: BEDFORD CECELIA A. , HARRISON F. A. , HEAP R. B.
Published: December 2008

Tracer kinetic techniques were used to determine the metabolic clearance rate (MCR) and production rate (PR) of progesterone in the sheep during pregnancy, the oestrous cycle and the lactation anoestrus. The MCR from whole blood measured by the continuous infusion of [3H]progesterone was 3·483 ± 0·126 l/min in pregnancy, 2·752 ± 0·239 l/min in the oestrous cycle and 5·020 ± 0·566 l/min in lactation anoestrus. After correcting for body weight the respective values were 0·077, 0·077 and 0·133 l/min/kg. The PR ranged from 0·60 to 6·75 μ/min in the oestrous cycle and 6·66 to 72·14 μg/min in pregnancy. In the last 4 weeks of gestation the PR of progesterone was significantly greater in ewes bearing foetuses with birth weights of more than 4 kg than in ewes with smaller lambs.

The conversion or isotope concentration ratio of progesterone to 20α hydroxypregn-4-en-3-one (20α-diHP) was 69·4±10·0% in non-pregnant and 77·2 ± 4·8% in pregnant sheep. The concentrations of [3H]progesterone and [3H]20α-diHP were closely correlated.

There was an appreciable extraction (25·4 ± 3·0%) of progesterone and production (9·1 ± 2·0% of 20α-diHP by the head.
CORTICOSTEROIDOGENESIS IN ISOLATED ADRENAL CELLS: EFFECT OF ADRENOCORTICOTROPHIC HORMONE, ADENOSINE 3′,5′-MONOPHOSPHATE AND β1–24ADRENOCORTICOTROPHIC HORMONE DIAZOTIZED TO POLYACRYLAMIDE
Authors: RICHARDSON M. C. , SCHULSTER D.
Published: December 2008

A cell suspension was prepared from normal rat adrenal tissue by collagenase digestion of decapsulated adrenal glands. Corticosterone produced by these cells was assayed both by competitive protein binding and by radioimmunoassay (range: 0–1 ng; sensitivity: 30 pg). Before incubation, the medium and cells equivalent to one gland contained 27·7 ± 3·2 ng corticosterone which increased to 36·3 ± 7·0 ng corticosterone after 1 h of incubation. Although a normal sigmoid log dose—response curve was obtained using adrenocorticotrophin (ACTH) (ED50:1·2 × 10−4 i.u./ml), it was observed that log (ACTH concentration) was directly proportional to log (corticosterone produced) between 1 × 10−7 and 1 × 10−3 i.u. ACTH/ml. A similar linear relationship was demonstrated for the effect of adenosine 3′,5′-monophosphate on steroidogenesis. Time-course studies revealed that after addition of ACTH there was a definite lag (3 min) before onset of increased steroidogenesis; within 5 min a constant corticosterone production rate was achieved. β1–24 Adrenocorticotrophin was shown to retain its ability to stimulate steroidogenesis when diazotized to beads of polyacrylamide too large to enter cells. Evidence is provided that the activity of the β1–24 ACTH—polyacrylamide beads is not due to biologically active peptides cleaved from the complex.

It is concluded that ACTH can stimulate steroidogenesis without entering its target cells.
STRAIN DIFFERENCES IN TESTICULAR WEIGHT AND SPERMATOGENESIS WITH SPECIAL REFERENCE TO C57BL/10J AND DBA/2J MICE
Authors: SHIRE J. G. M. , BARTKE A.
Published: December 2008

Marked differences were found in the absolute and relative weights of the testes of young adult mice from 11 strains. DBA/2J mice had large testes (936 ± 46 mg/100 g body weight) and C57BL/10J mice had small ones (389 ± 6 mg/100 g). Comparisons of mice from these two strains, raised under three different environmental conditions, showed that the difference between the strains was relatively unaffected by environmental variation. Measurements on hybrid mice confirmed that much of the observed difference between the two strains was genetic in origin.

The C57BL/10 mice were unlike those of any of the other strains in that both the relative and the absolute weights of the testis declined between the ages of 9 and 16 weeks.

Strain differences were also found when spermatogenesis was studied in four of the strains by counting the different types of germinal cells in seminiferous tubules in stage VII of spermatogenesis. There were about twice as many type A spermatogonia in DBA/2 mice as there were in C57BL/10 mice. The mean numbers of spermatocytes and spermatids were much greater in DBA/2 than in C57BL/10. These differences were sufficient to account for the observed differences between these strains in testicular weight.

Reciprocal F1 mice resembled their DBA/2 parents both in the weight of their testes and in the pattern of spermatogenesis.

It is suggested that, in comparison with mice of the other strains, C57BL/10J mice may be deficient in androgenic hormones.
DIFFERENCES BETWEEN MOUSE STRAINS IN TESTICULAR CHOLESTEROL LEVELS AND ANDROGEN TARGET ORGANS
Authors: BARTKE A. , SHIRE J. G. M.
Published: December 2008

The concentrations of esterified and free cholesterol in the testes, and the weights of the testes, seminal vesicles, kidneys and submandibular glands, were determined in mice of the C57BL/10J and DBA/2J inbred strains. Measurements were also made on reciprocal F1 hybrids. Cholesterol concentration and the weights of the testes and seminal vesicles were also studied in C57BL/6J and AKR/J inbred mice and in mice from two random-bred stocks. Considerable strain differences were found both in the concentration of esterified cholesterol and in gonadal weight. Since all the animals were maintained under the same environmental conditions the differences must have been genetic in origin. The decrease in absolute testicular weight which occurred in the C57BL/10 mice after the age of 8 weeks was accompanied by an increase in the percentage of total cholesterol present as ester. Groups of C57BL/10 males were treated with luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin-secreting pituitary isografts, pregnant mare serum gonadotrophin (PMS), testosterone propionate or pregnenolone. The concentration of esterified cholesterol was slightly decreased by LH and increased by pituitary grafts, confirming earlier studies in other strains. Treatment with PMS caused a drastic depletion of the high levels of esterified cholesterol usually found in the testes of these mice, and also caused marked growth of the seminal vesicles. Testosterone increased the weight of seminal vesicles while pregnenolone had no effect. None of the treatments stimulated spermatogenesis. A marked sex difference in the weight of the kidneys was absent in the C57BL/10 strain but was present in the DBA/2 strain. The kidneys of C57BL/10 males were significantly smaller than those of DBA/2 males. These findings, together with other studies on C57BL/10 mice, suggest that males of this strain are relatively androgen deficient. This could be due to inadequate production of FSH and LH, perhaps accompanied by a deficiency in the conversion of pregnenolone to androgenic steroids. The effect of the C57BL/10 genotype on spermatogenesis either is not hormone mediated or else is irreversible after the age of 6 weeks.
CENTRAL AND PERIPHERAL NEURAL INFLUENCES ON THE OXYTOCIN-INDUCED PRESSURE RESPONSE OF THE MAMMARY GLAND OF THE ANAESTHETIZED LACTATING RAT
Authors: GROSVENOR C. E. , DeNUCCIO D. J. , KING S. F. , MAIWEG H. , MENA F.
Published: December 2008

Intramammary pressure responses to intravenous injections of oxytocin were compared in the urethane-anaesthetized rat before and after various denervation procedures and before and after administration of various adrenergic blocking drugs. Intravenous administration of either phenoxybenzamine, propranolol or pentolinium after a period of time resulted in a more quickly ascending, higher amplitude pressure response but which usually returned more slowly — often oscillating — to the pre-existing basal pressure. Unilateral severance of the dorsal roots supplying the six abdomino-inguinal glands resulted in immediate though lesser increases in both the slope and amplitude of the intramammary pressure response. The responses were increased to a similar extent in contralateral as well as ipsilateral glands caudal to the point of root section whereas the responses of glands rostral to the section were unaffected. The effect of dorsal root section persisted unchanged in rats pretreated with either phenoxybenzamine or propranolol. The intramammary pressures also increased immediately when the segmental nerves were cut. The intramammary pressure was decreased in all glands tested after transecting the spinal cord between T-10 and T-11, then increased dramatically in slope and amplitude over the next 1 to 2 h in glands caudal to the level of section; the responses of glands rostral to the level of cord section were unchanged. The resulting high amplitude responses obtained after cord section usually oscillated and were slow to return to pre-existing basal pressures. The intramammary pressure profile changed in a manner similar to that following spinal cord section when 25% KCl was placed bilaterally on the cerebral cortices. The effect of KCl persisted in rats pretreated with phenoxybenzamine and pentolinium. The results obtained from these experiments suggest that a diffuse motor control of ductal and vascular tone exists in the rat mammary gland which appears to be inhibitory in function and to be sensitive to central as well as to peripheral influences.
METABOLISM OF ETHYNYLOESTRADIOL IN MAN
Authors: REED M. J. , FOTHERBY K. , STEELE S. J.
Published: December 2008

The metabolism of 17α-ethynyloestradiol was studied in one man and 16 women. After intravenous or oral administration, 22·6–46·9% of the dose was excreted in the urine over a 5-day period. Up to 36% of the urinary radioactivity may be present in the unconjugated form with a further 64% being extractable after enzymic hydrolysis. Sulphate conjugates formed only 11·4% of the urinary radioactivity. Semi-quantitation of these extracts showed ethynyloestradiol itself to be the major metabolite, accounting for 3·2–8·4% of the administered dose in the unconjugated fraction with a further 2·4–16·5% in the enzyme hydrolysed fraction. Up to 16·5% of the dose was therefore excreted unchanged, and metabolites less and more polar than ethynyloestradiol were also found. Excretion via the faeces accounted for up to 30% of the administered dose, with most of the extractable radioactivity being in the unconjugated form. Ethynyloestradiol accounted for up to 29·6% of faecal radioactivity. No significant amounts of radioactivity were detected in sweat collected from one subject 2 or 24 h after administration of the dose. Plasma levels of 3·32% and 1·72% of the administered dose per litre were found 1 and 24 h after administration. Metabolites in plasma were present mainly as sulphate conjugates.
CYCLIC AMP AND THE DIFFERENTIATION OF ADRENAL CORTICAL CELLS GROWN IN TISSUE CULTURE
Authors: MILNER A. JOSEPHINE
Published: December 2008

Primary tissue cultures of adrenal cells were prepared from foetal rat adrenals. The effect of cyclic AMP (75 μmol/l) on the morphology and steroid synthetic activity of the cortical cells was examined in order to determine whether cyclic AMP mimics the effects induced by adrenocorticotrophin (ACTH); namely transformation to the differentiated cell type and increase in steroid synthetic activity. Cyclic AMP was found to induce some, but not all, of the changes normally induced by ACTH. In particular, the mitochondria in the cortical cells developed vesicular cristae and there was a proliferation of the smooth endoplasmic reticulum. These two organelles are the principle sites of enzymes involved in steroid synthesis and the ultrastructural transformation was accompanied by an increase in the steroidogenic activity of the cells. However, clear differences in the ultrastructure of the cyclic AMP- and ACTH-treated cells were noted. The effects of cyclic AMP on the ultrastructure of cortical and fibroblastic cells present in the adrenal cultures were found to be dependent upon the cell type.
IMPLANTATION AND ATTACHMENT REACTION OF RAT UTERINE LUMINAL EPITHELIUM AT A HIGH DOSE OF OESTRADIOL
Authors: LJUNGKVIST I.
Published: December 2008

The injection of 5 μg oestradiol to progesterone-treated spayed, pregnant rats caused implantation in some rats but not in others. In rats with implantation the epithelium underwent a change similar to that during normal implantation, i.e. an attachment reaction. No attachment reaction was seen in rats without implantation or in progesterone-treated, spayed, virgin rats. The results may support the idea that the attachment reaction is the morphological sign of a receptive uterus and that the reaction is functionally related to the onset of implantation. Further, they indicate that the sensitivity to oestrogen varies between rats during delayed implantation.
THE DISTRIBUTION OF CORTISOL AND ITS RATE OF TURNOVER IN NORMAL AND COLD-STRESSED SHORN SHEEP
Authors: PANARETTO B. A. , VICKERY MARION R.
Published: December 2008

Cortisol pools were examined in six shorn sheep before (i.e. control conditions) and during their exposure to a cold, wet environment. Cortisol labelled with tritium was infused until equilibrium concentration [3H(eq)] was reached in the plasma; the infusion was then stopped and the instantaneous concentrations [3H(t)] determined at intervals during the next 20–40 min. A two-pool model was used to calculate results and the rate constants k10, k12 and k21 were used to describe catabolism of hormone from the central pool, movement from the central to the outer pool and in the reverse direction respectively.

In the majority of cases when the fractional concentrations, [3H(t)]/-[3H(eq)], after infusion were plotted against time, curves representing control conditions indicated that the apparent rate of disappearance of cortisol from plasma was faster than from cold-stressed normothermic sheep. The apparent rate of disappearance of cortisol from the plasma of both control and cold-stressed normothermic sheep was faster than when the animals were hypothermic. These results were not obtained in two sheep when they were cold-stressed and normothermic and these are discussed.

The rate constants k10, k12 and k21 obtained in the experiments bore the relation control < cold-stressed normothermic < hypothermic. The total amount of cortisol increased about 4 times, relative to control, when the sheep were cold-stressed and normothermic, and 40 times, relative to control, when they were hypothermic. Pools decreased in one cold-stressed normothermic sheep. Turnover rates were 7·7%, 7·0% and 3·7% of the total pool/min for sheep under control, cold-stressed normothermic and hypothermic conditions respectively.

It is concluded that the greatly increased plasma cortisol concentrations detected in cold-stressed normothermic and hypothermic sheep were associated with great increases in total cortisol, distributed in relatively constant 'spaces' in the body under those conditions.
OVULATION INDUCED BY PREGNANT MARE SERUM GONADOTROPHIN IN THE IMMATURE RAT TREATED NEONATALLY WITH A LOW OR A HIGH DOSE OF ANDROGEN
Authors: UILENBROEK J. Th. J. , ten BOSCH J. J. van der WERFF
Published: December 2008

Ovulation-inducing effects of pregnant mare serum gonadotrophin (PMSG) were studied in immature female rats treated on day 5 (day 1 = day of birth) with oil or with 5 or 1250 μg testosterone propionate (TP). The response of rats treated with 1250 μg TP was negligible regardless of the age of the animals and of the dose of PMSG. The response of rats treated with 5 μg TP to PMSG alone was low (36% of rats, with 2·6 ova/ovulating rat), but could be improved by progesterone administration 2 days after PMSG injection (91% of rats, with 14·5 ova/ovulating rat). At every age and dose of PMSG tested the response of animals treated with 5 μg TP to combined PMSG and progesterone treatment was less than that of control animals.

It is concluded that neonatal TP treatment diminishes the release of endogenous ovulating hormone subsequent to PMSG injection. This effect is dependent on the dose of TP used, but already demonstrable in animals treated with 5 μg TP on day 5, which would have been cyclic and fertile after puberty.

Only for the animals treated with 1250 μg TP could a decreased sensitivity of the ovaries to combined administration of PMSG and human chorionic gonadotrophin be demonstrated.
REVERSIBLE BINDING OF LABELLED AND NON-LABELLED THYROTROPHIN BY INTACT THYROID TISSUE IN VITRO
Authors: MANLEY S. W. , BOURKE J. R. , HAWKER R. W.
Published: December 2008

125I-Labelled thyrotrophin (TSH) showed saturable binding to hyperplastic guinea-pig thyroid slices in vitro, but not to kidney, adrenal, liver, testis or salivary gland slices. Two populations of binding sites were demonstrated: high order sites showed an affinity constant of 3·8 × 1081/mol and a capacity of 8 × 103 molecules of TSH/cell; low order sites, affinity constant of 2·9 × 1071/mol and capacity of 8 × 104 molecules/cell. The highorder sites saturate at about 1 mu./ml, approximately the level producing maximal in-vivo and in-vitro responses. Binding of 125I-labelled TSH was reversible, the released hormone appearing substantially unchanged as assessed by chromatographic behaviour and antiserum binding. Release of unlabelled TSH from pre-incubated thyroid slices was demonstrated by bioassay. Bovine thyroid slices were found to have a lower capacity for binding than hyperplastic guinea-pig slices.
SERUM LIPID PATTERN IN CHICKENS OF THE OBESE STRAIN
Authors: RUDAS BARBARA , WICK G. , COLE R. K.
Published: December 2008

Blood sugar, the serum concentration of total lipids, total glycerol, cholesterol and phosphatides were determined in chickens from the Obese strain (OS) of White Leghorns. Over 90% of these chickens are afflicted with a spontaneously occurring autoimmune thyroiditis and show clinical symptoms of hypothyroidism. Blood glucose levels were increased above normal limits in OS chickens up to 5 weeks of age. Significantly increased serum lipid concentrations were found in the OS chickens at the ages of 1, 5, 8 and 15 weeks, while 3-week-old OS chickens showed almost normal serum lipid levels. A single intravenous injection of heparin in a dose which prolonged bleeding time, had no 'clearing effect' on the serum of OS birds. Insulin given subcutaneously for 4 days had no effect on blood sugar but decreased the serum phosphatides and total lipid concentrations. The short-term administration of high doses of thyroxine significantly lowered the serum levels of total lipids, cholesterol, phosphatides and total glycerol.
THE EFFECT OF UNILATERAL OVARIECTOMY IN THE NEONATAL MOUSE ON FOLLICULAR DEVELOPMENT
Authors: PETERS HANNAH , BRAATHEN BRITT
Published: December 2008

The remaining ovary of a 14-day-old mouse after unilateral ovariectomy (ULO) on day 2 showed the same number and stages of follicles as an ovary in an intact animal of the same age. No increase in the number of developing follicles nor development to more advanced stages occurred. Hemispaying in the neonatal period did not alter the number of follicles that started growth nor their speed of development in the subsequent 12 days. However, premature follicle fluid accumulation and a widening of the theca layer in early growing follicles were characteristically found in the remaining ovary. The failure of the remaining ovary to increase its complement of large follicles is probably due to the fact that those follicle stages (i.e. large follicles) which are able to react to stimulation by follicle-stimulating hormone in the prepubertal and adult ovary are as yet lacking in the early infant ovary. However, reaction to luteinizing hormone can already be expressed and is shown by premature follicle fluid accumulation and widening of the theca layer. The changes seen are interpreted as a reaction of the remaining ovary to a relative increase in an unchanged amount of available gonadotrophin rather than to a change in the pituitary—gonadal feedback mechanism.
MEASUREMENT OF CANINE PITUITARY PROLACTIN
Authors: SALUJA P. G. , GRONOW M. , HAMILTON J. M.
Published: December 2008

Isoelectric focusing in polyacrylamide gel followed by staining with Coomassie brilliant blue was used for the densitometric estimation of ovine prolactin standard and canine pituitary prolactin. The results were compared with those obtained by conventional polyacrylamide gel electrophoretic procedures and isoelectric focusing was found to be a valid technique for the estimation of prolactin and to offer greater technical convenience.

The mobility of ovine and canine prolactin was similar in isoelectric focusing and gel electrophoresis. The isoelectric point of ovine and canine prolactin was found to be 6·17 and 6·61 respectively.

Constant levels of prolactin were found in the pituitaries of bitches at oestrus.
INVOLVEMENT OF THE UTERINE BLOOD VESSELS IN THE REFRACTORY STATE OF THE UTERINE STROMA WHICH FOLLOWS OESTROGEN STIMULATION IN PROGESTERONE-TREATED MICE
Authors: MARTIN L. , HALLOWES R. C. , FINN C. A. , WEST D. G.
Published: December 2008

Increases in uterine capillary permeability after the injection of oestradiol into spayed mice, appeared to be caused by the development of vascular fenestrations and not by the separation of adjoined endothelial cells. Progesterone did not prevent the uterine weight, oedema and vascular responses to the first of two injections of oestradiol but inhibited those to the second. It was concluded that the failure of repeated oestrogen-treatment to produce uterine oedema in progesterone-treated mice resulted from the refractory state which develops after the first injection and which extends to the endometrial vasculature.
THE DISTRIBUTION AND METABOLISM OF LABELLED CORTICOSTEROIDS IN THE DUCK (ANAS PLATYRHYNCHOS)
Authors: HELTON E. D. , HOLMES W. N.
Published: December 2008

After the injection of [1,2-3H]corticosterone into ducks, no unaltered free [1,2-3H]corticosterone was found in either bile, gut contents or cloacal fluid. All the [1,2-3H]corticosterone metabolites in cloacal fluid had similar chromatographic mobilities. A portion of these metabolites was steroid ester sulphate but enzymic hydrolysis suggested that only a small fraction of the sulphate was conjugated to [1,2-3H]corticosterone. The amount of ester sulphate in samples of cloacal fluid, however, was highly variable.

After the injection of [1,2-3H]aldosterone one-fifth of the total radioactivity in urine was free [1,2-3H]aldosterone but none was found in the bile and gut contents. Chromatographic purification of the [1,2-3H]aldosterone metabolites in cloacal fluid showed two significant peaks and both peaks contained steroid ester sulphates. Enzymic hydrolysis of the tritiated material showed that each peak also contained a glucuronide of [1,2-3H]aldosterone.

The effect of the entero-hepatic circulation on the excretion of tritiated metabolites by the kidney was also examined. Diversion of bile from the duodenum prevented the entry of radioactive material into the gut. The reduced reabsorption of tritiated corticosterone and tritiated aldosterone metabolites from the gut, however, did not affect the amount of tritium excreted by the kidneys. In the case of both hormones, some of the reabsorbed metabolite which had been extracted by the liver was released and re-entered the peripheral blood via the hepatic circulation. The stress of surgery in both the control birds and the birds with bile catheters caused the distribution of [1,2-3H]corticosterone and the tritiated corticosterone metabolites to change; a significantly smaller percentage of the injected radioactivity was recovered from the tissues and excretory fluids. This response to stress was not observed in the [1,2-3H]aldosterone injected birds.

When partially purified metabolites of [1,2-2-3H]corticosterone and [1,2-3H]aldosterone were injected into the lumen of the gut, the rate of uptake of the tritiated corticosterone metabolites was higher than that of the tritiated aldosterone metabolites. But, when the metabolites of [1,2-3H]corticosterone and [1,2-3H]aldosterone were injected intravenously, and the rate of the intestinal reabsorption of the metabolites was not limiting, the rates of tritium excretion by the kidneys were the same. The volumes of distribution and metabolic clearance rates of the partially purified [1,2-3H]corticosterone and [1,2-3H]aldosterone metabolites were significantly different from one another and the metabolites could be readily distinguished physiologically as well as chromatographically. The pattern of distribution and the disappearance from plasma of i.v. administered synthetic [1,2-3H]corticosterone-21-SO4 was also distinguishable from the naturally occurring metabolites of [1,2-3H]corticosterone.
HORMONAL REQUIREMENTS FOR THE MAINTENANCE OF LUTEAL FUNCTION IN HYPOPHYSECTOMIZED, PSEUDOPREGNANT RATS
Authors: TAKAYAMA MASAOMI , GREENWALD G. S.
Published: December 2008

Pseudopregnant rats with traumatized uteri were hypophysectomized on day 6 and injected with various hormones over the next 4 days. Luteal function was assessed on day 10 of pseudopregnancy by weighing deciduomata and determining luteal and plasma levels of progesterone by a competitive protein-binding assay. Daily treatment with 0·25 mg prolactin restored plasma and luteal levels to the values of intact pseudopregnant animals; however, the deciduomata weighed only 55% of control values. Combining oestrone with prolactin restored deciduomata weight to control values without affecting peripheral progesterone levels.

Either 200 μg of follicle-stimulating hormone (FSH) or 5 μg luteinizing hormone (LH) could be substituted for oestrone, in conjunction with prolactin, to increase deciduomata weight to control values. Moreover, the combination of prolactin with FSH or LH significantly increased peripheral plasma levels of progesterone beyond the effects of prolactin alone. Higher doses of LH were luteolytic as shown by decreased deciduomata weight and considerable variation in plasma and luteal values of progesterone. LH given alone — either in saline or polyvinyl pyrrolidine — failed to maintain any of the parameters of luteal activity mentioned above.

The results reaffirm the primacy of prolactin in vivo as the principal luteotrophic hormone of the rat and indicate that selected doses of LH or FSH play an additive role in further increasing peripheral levels of progesterone.
DISTRIBUTION OF OESTROGEN RECEPTORS IN CELL FRACTIONS OF HUMAN UTERINE TISSUE
Authors: EVANS L. H. , HÄHNEL R.
Published: December 2008

[3H]Oestradiol-17β binding by cytoplasmic and nuclear fractions of human uterine tissue homogenates was studied by intact tissue and cell-free incubation techniques. In the absence of divalent cations, swelling and rupture of endometrial nuclei led to a loss of nuclear receptor complex into the cytoplasmic fraction of the homogenate. Divalent cations at a concentration of 0·003 mol/l, however, caused precipitation of the cytoplasmic receptor complex, inhibited [3H]oestradiol-17β binding by the cytoplasmic receptor and inhibited the extraction of soluble nuclear receptor complex. These effects were minimal when 0·001 m-magnesium ions were added to the sucrose—tris buffer. Studies of the distribution of oestrogen receptors in homogenates of human uterine tissue in 0·001 m-magnesium—sucrose—tris buffer revealed the presence of a soluble and an insoluble nuclear receptor complex. More of the nuclear receptor complex was obtained in the soluble form when the incubation temperature was raised from 25 to 37 °C. Evidence is presented for the transfer of [3H]oestradiol-17β from the cytoplasmic to the nuclear fractions by a temperature-dependent process and for the binding of [3H]oestradiol-17β by nuclear receptors in the absence of the cytoplasmic fraction.
THE RATE CONSTANTS FOR THE INTERACTION OF CORTISOL AND TRANSCORTIN, AND THE RATE OF DISSOCIATION OF TRANSCORTIN-BOUND CORTISOL IN THE LIVER
Authors: PATERSON J. Y. F.
Published: December 2008

The apparent rate of dissociation of transcortin-bound cortisol in human plasma was measured. After establishing equilibrium between plasma proteins and endogenous and added [3H]cortisol, this was perturbed by addition of a known amount of exogenous cortisol. Plasma protein-bound [3H]cortisol was then measured by gel filtration at timed intervals.

This system can be described by six differential equations, one each for unbound, albumin-bound and transcortin-bound cortisol and [3H]cortisol. The rate constants for the transcortin—cortisol reaction were estimated by numerical solution of these equations, using arbitrary rate constants for the albumin—steroid reaction.

At 2 °C the dissociation of transcortin-bound cortisol has a rate constant of 0·00041 s−1, at 10 °C 0·00179 s−1 and at 22 °C 0·0353 s−1. At 37 °C the reaction was very rapid and equilibrium appeared to be attained in less than 5 s. The rate constant could only be estimated by using the Arrhenius equation, In (k) = const + E/RT, and was found to be 0·633 s−1.

The rate constants for cortisol—plasma protein interaction were applied to a differential equation model for the splanchnic uptake of cortisol. Using experimental measurements of the visceral and hepatic uptake of cortisol in sheep the rate constant for the visceral removal of cortisol was found to be 0·0299 ± 0·0065 (s.e.m.) s−1 and the hepatic constant was 0·4674 ± 0·0540 (s.e.m.) s−1. In normal conscious sheep the total splanchnic uptake of cortisol appeared to be derived 42% from unbound, 31% from albumin-bound and 27% from transcortin-bound steroid.
ANDROGENIZATION OF THE NEONATAL FEMALE RAT WITH VERY LOW DOSES OF ANDROGEN
Authors: SHERIDAN P. J. , ZARROW M. X. , DENENBERG V. H.
Published: December 2008

The administration of a high dose of androgen on a single day to a neonatal female rat has been shown repeatedly to induce persistent vaginal cornification (PVC). However, this type of treatment does not parallel the continuous androgen secretion present in the male, and the high doses that have been used could represent a pharmacological and not a physiological effect. Experiments were carried out to determine the minimal effective dose of testosterone propionate (TP) needed to cause PVC when the androgen is administered to the neonatal rat for the first 10 days of life or as a long-acting ester. Injection of 1, 3 or 9 μg TP on days 1–10 of life in female rats induced PVC in adulthood. All three doses were found to be more effective than a testicular transplant on day 1. In female rats injected with low doses of TP twice daily for the first 10 days of life, PVC was shown between 90 and 100 days of life in 21 out of 22 animals given 0·5 μg TP/injection, and in eight out of 22 animals given 0·05 μg TP/injection. In an experiment where female rats were given a single injection of 0·1, 1·0 or 10·0 μg TP, or 0·1 or 1·0 μg testosterone cyclopentylpropionate (TC, a long-acting androgen) on the first day after birth, PVC occurred at 90–100 days of age in 15 of the 18 animals which were injected with 10 μg TP, in none of the 17 animals which were injected with 1 μg TP, and in 10 of 11 animals which were injected with 1 μg TC. The effects of all treatments on vaginal opening, first oestrus, ovarian weight, body weight and sexual behaviour are reported. The use and implications of low dose regimens are discussed in relation to the construction of an experimental model for the study of sexual differentiation.
INITIATION OF PARTURITION IN THE RABBIT BY MATERNAL AND FOETAL ADMINISTRATION OF CORTISOL: EFFECT OF RATE AND DURATION OF ADMINISTRATION: SUPPRESSION OF DELIVERY BY PROGESTERONE
Authors: NATHANIELSZ P. W. , ABEL MARGARET
Published: December 2008

Continuous infusion of cortisol at rates from 0·31 to 1·24 mg/h into pregnant rabbits from day 21 of pregnancy onwards induced delivery in approximately 72 h. Similar rates of infusion into the foetal amniotic sac induced delivery with a shorter latency. Maternal infusion of 1·24 mg cortisol/h produced parturition providing it was continued for at least 24 h. If after this period the infusion was terminated, delivery still occurred after a further 48 h (i.e. 72 h in all). Progesterone administration to the mother blocked the effect of cortisol administered by the maternal or foetal route.