bluuebunny/crossref_metadata_2025_split huggingface dataset:
EFFECTS OF FOLLICLE-STIMULATING HORMONE AND LUTEINIZING HORMONE ON PLASMA TESTOSTERONE LEVELS IN HYPOPHYSECTOMIZED AND IN INTACT IMMATURE AND ADULT MALE RATS
Authors: SAFOURY S. EL , BARTKE A. 
Published: December 2008

SUMMARY
The effects of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) on plasma testosterone levels were examined in hypophysectomized and in intact immature and adult male rats. The animals were injected with saline, LH, FSH, or both gonadotrophins twice daily for 3·5 days and were killed 3 h after the last injection. Plasma testosterone levels were measured by radioimmunoassay.
In immature hypophysectomized rats, plasma testosterone levels were not changed by treatment with LH, FSH or LH plus FSH. The weight of the testes and of the seminal vesicles was increased only in animals injected with both LH and FSH.
In adult hypophysectomized rats, LH caused the expected increase in plasma testosterone levels, while FSH injected alone had no effect. Plasma testosterone levels in rats treated with 5 μg LH and 20 μg FSH were significantly greater than those in animals given 5 μg LH alone. However, the same dose of FSH did not potentiate the action of 25 μg LH on plasma testosterone levels. In adult hypophysectomized rats the weight of testes was not affected by any of the treatments. The weight of the seminal vesicles was increased by the higher dose of LH and addition of FSH caused no further increase.
In intact immature and adult rats plasma testosterone levels and the weight of testes were not changed by any of the treatments. Seminal vesicle weight was increased only in adult rats treated with the higher dose of LH together with FSH.
The results demonstrate that FSH potentiates the action of low doses of LH on plasma testosterone levels in adult hypophysectomized rats and suggest that FSH may be involved in the regulation of androgen secretion by the rat testis.
THE EFFECTS OF OESTRUS AND EXOGENOUS OESTROGENS ON MILK SECRETION IN THE GOAT
Authors: PEAKER M. , LINZELL J. L. 
Published: December 2008

SUMMARY
Changes in the composition of the aqueous phase of milk were found to precede oestrus by up to 4 days in five out of six goats. However, the composition had returned to normal by the time oestrous behaviour was first observed. The alteration in composition was characterized by increases in milk sodium and chloride concentrations, and decreases in potassium and lactose; fat, protein and immunoglobulin concentrations were unaffected. These changes were also observed in autotransplanted (i.e. denervated) glands.
Large doses of exogenous oestrogens (to match the secretion rate in late pregnancy) administered to goats in anoestrus resulted in a significant fall in milk yield, increases in milk fat, protein, immunoglobulin and sodium concentrations, and a decrease in potassium. Chloride and lactose concentrations were not significantly changed except in some goats when the milk yield was severely affected 4 days after oestrogens were given i.m.
Possible hormonal mechanisms and the nature of the changes in the secretory epithelium before oestrus and as a result of oestrogen treatment are discussed.
INFLUENCE OF SEX AND AGE ON THE CORTISOL CONTENT OF PERIPHERAL TISSUES AND ADRENAL GLANDS IN THE GUINEA-PIG
Authors: FAZEKAS A. T. A. , HOMOKI J. , TELLER W. M. 
Published: December 2008

SUMMARY
The influence of age and sex on the cortisol content of adrenals, liver, kidney, lung, heart, spleen, muscle, cerebrum, brain stem and blood was studied in white guinea-pigs.
In prepuberal animals no significant difference between sexes was found in the cortisol content of different tissues. In adult female animals, the blood cortisol level was significantly higher than in the male animals. Significantly more cortisol was found in kidneys of adult male than of female animals.
In adult guinea-pigs, the cortisol content was lower in every tissue examined, except liver, compared with young animals. These differences were highly significant. In female guinea-pigs the decrease in tissue cortisol content with age was more pronounced than in male animals.
METABOLIC RESPONSE TO MALE HORMONE AND THYROID ACTIVITY IN THE INDIAN GARDEN LIZARD, CALOTES VERSICOLOR
Authors: CHANDOLA ASHA , KUMAR D. SURESH , THAPLIYAL J. P. 
Published: December 2008

SUMMARY
Thyroidectomy and orchidectomy led to significant reduction in the oxidative metabolism of isolated liver and skeletal muscle tissue (at 30 °C) in Calotes versicolor. Thyroxine and male hormone were shown to increase this parameter in intact and orchidectomized lizards respectively. The effects of thyroidectomy and orchidectomy on tissue oxygen uptake were not additive. It is supposed that by its effect on oxidative metabolism male hormone may be of a greater physiological importance for reptiles than for other vertebrates.
The present results show also that changes in environmental temperature can counteract the depressive effect of orchidectomy on the thyroid of this species of lizard.
THE RELATIONSHIP BETWEEN THE CHANGES IN THE INTERRENAL, GONADAL AND THYROIDAL TISSUE OF THE AIR BREATHING FISH, HETEROPNEUSTES FOSSILIS (BLOCH) AT DIFFERENT PERIODS OF THE BREEDING CYCLE
Authors: SINGH B. R. , THAKUR R. N. , YADAV B. N. 
Published: December 2008

SUMMARY
The interrenal tissue of the air-breathing fish, Heteropneustes fossilis, became hypertrophied during the breeding period. The interrenal cell cytoplasm became acidophilic and vacuolated, cytoplasmic granulation disappeared and the cell nuclei increased in size. The diameter of the nuclei varied from 2·07 to 3·12 μm in the non-breeding period while in the breeding season there was almost uniform enlargement (4·54 ± 0·36 μm). Variation in nuclear size was most pronounced during maturation of the gonads, i.e. in April. However, the size of larger nuclei (average diameter 6·53 ± 0·98 μm) was not significantly different from that of thesmaller nuclei (average diameter 4·61 ± 0·61 μm) during this period (P > 0·05).
The volume density of the cell components of the interrenal tissue nearly doubled in the breeding period but the relative proportions remained more or less the same. Glycogen granules, which appeared to be uniformly distributed in the interrenal cells in the non-breeding period, became aggregated and clumped in many parts of the cell during the breeding period. There was a clear increase in the chromaffin reaction in the chromaffin cells during the breeding period but the iodate reaction, indicating noradrenaline content, decreased considerably.
In the ovarian cycle there was a close relationship between gonadosomatic index, ova diameter and water temperature. There was a more than tenfold increase in the gonadosomatic index in the breeding period (1·30 in the non-breeding and 15·27 in the breeding periods). In males, the rise in the gonadosomatic index in the breeding period corresponded to that of the ovary in degree (0·22 in the non-breeding and 3·20 in the breeding periods).
In the non-breeding period the thyroid follicles were composed of squamous epithelium (epithelial height 1·2–2·2 μm) with a follicular diameter of 48–76 μm and the colloid completely filling the lumina of the follicles; features indicative of hypofunction of the gland. In the breeding period, the follicles were composed of cuboidal epithelium (epithelial height nearly three times that in the preceding period, 4·1–6·3 μm) follicular diameter was reduced (36–48 μm) and the colloid incompletely filled the lumina, thus suggesting normal or slight hyperfunction of the gland.
GENETIC STUDY OF THE EFFECTS OF [8-ARGININE]- AND [8-LYSINE]-VASOPRESSINS ON ADENYL CYCLASE ACTIVITY OF MOUSE KIDNEY
Authors: STEWART A. D. 
Published: December 2008

SUMMARY
Adenyl cyclase was measured in vitro in renal medullary homogenates from male mice of the Peru and CBA/FaCam strains. The basal activity of adenyl cyclase was increased on incubation with 30 mm-NaF and with varying concentrations of [8-arginine]-vasopressin (AVP) and [8-lysine]-vasopressin (LVP) up to 100 mu./ml. In both strains of mice, the maximal hormone activation was the same whichever vasopressin was used, and the same degree of stimulation was observed on incubation of homogenates with both hormones together. It is concluded that both hormones have the same intrinsic activity in this system, and are acting on the same population of receptors within each strain of mouse.
Half-maximal adenyl cyclase activation was achieved with 240 ± 50 (s.e.m.) μu. AVP/ml and 920 ± 160 μu. LVP/ml in homogenates from CBA/FaCam mice; and 240 ± 40 μu. AVP/ml and 1900 ± 250 μu. LVP/ml in Peru mice. These results are compared with previously reported potencies in these mice of the two vasopressins as antidiuretic agents in vivo. Whilst there is good agreement between results in vitro and in vivo with CBA/FaCam mice, there is a highly significant discrepancy with Peru mice. Explanations for these results, including the possibility that cyclic AMP may not be the sole mediator of the increased water permeability of the distal tubule induced by vasopressin, are discussed.
THE INFLUENCE OF SURGERY, TIME OF DAY, BLOOD VOLUME REDUCTION AND ANAESTHETICS ON PLASMA PROLACTIN IN OVARIECTOMIZED RATS
Authors: LAWSON D. M. , GALA R. R. 
Published: December 2008

SUMMARY
Plasma prolactin was measured by double antibody radioimmunoassay in ovariectomized rats bearing indwelling aortic catheters. Samples were obtained during recovery from ovariectomy and catheterization, at various times during the day, after blood volume reduction, and after administration of various anaesthetics. Prolactin levels were stabilized by day 3 after the operation but not by day 1. There was a significant (P < 0·01) increase in plasma prolactin during the afternoon in both ovariectomized rats and ovariectomized rats treated with 1 mg polyoestradiol phosphate. The magnitude of the response was more pronounced in the animals treated with oestrogen. Withdrawal of blood samples without subsequent replacement of fluid volume induced a significant (P < 0·05) decrease in plasma prolactin concentration after removal of only 1·2 ml blood within 20 min. No change was observed, however, when blood was replaced with saline. Ether and the intraperitoneal injection of sodium pentobarbitone produced prolonged increases in plasma prolactin whereas the intra-arterial administration of sodium pentobarbitone produced no change. Urethane and chloral hydrate caused only transient increases in plasma levels of prolactin regardless of the route of administration. Ketamine did not significantly alter plasma levels of prolactin.
THE ROLE OF PROLACTIN IN THE DEPRESSED OR 'BUFFERED' ADRENOCORTICOSTEROID RESPONSE OF THE RAT
Authors: SCHLEIN P. A. , ZARROW M. X. , DENENBERG V. H. 
Published: December 2008

SUMMARY
Lactating female rats are known to exhibit a reduced or 'buffered' plasma corticosterone response to stress. The depressed response is a post-partum phenomenon seen only in the lactating rat with pups, since a lactating rat whose pups have been removed for 8 days gives a normal response to ether stress. Thus it appears that lactation may be necessary for a reduced response to stress, and the reappearance of the normal response coincides with the time when the animal resumes its oestrous cycle. Maternal behaviour by itself could be ruled out as a causative factor since a normal adrenal response was seen in virgin rats which had been sensitized to pups.
A depressed corticosteroid response to ether stress was obtained after ovariectomy or treatment with prolactin (2 mg/day for 5 days). However, the effect of ovariectomy on plasma corticosterone levels after ether stress could be reversed by the injection of 5 μg oestradiol benzoate daily for 5 days.
The minimum effective dose of dexamethasone phosphate that was necessary to prevent increased plasma corticosterone levels after ether stress in the normal female rat was 400 μg/100 g body weight whereas a lactating rat required only 6·25 μg and a virgin rat treated with prolactin required 25 μg. It is apparent that prolactin is acting, in part at least, to increase the sensitivity of the negative feedback system.
PROGESTERONE AND OESTRADIOL-17β CONCENTRATIONS IN THE PERIPHERAL PLASMA DURING PREGNANCY IN THE MOUSE
Authors: McCORMACK J. T. , GREENWALD G. S. 
Published: December 2008

SUMMARY
The concentration of progesterone and oestradiol-17β in peripheral plasma was determined by radioimmunoassay on each day of pregnancy in the mouse. The progesterone concentration, low on days 1 and 2, correlated with the histological development of the corpora lutea. Progesterone levels during the first half of pregnancy rose to a peak on day 6 with a significant decrease (P < 0·02) on day 7. Peripheral progesterone concentration during the second half of pregnancy rose on days 12–13 with a peak on days 14–17, and declined after day 17, 3 days before the onset of parturition.
Oestradiol-17β concentrations were high on day 1, declined precipitously to low levels on days 2 and 3 recovering slightly on day 4. The levels then fell and remained low from day 5 to days 15–16, when there was a significant increase in oestradiol-17β concentration which continued until day 20.
INHIBITION AND MAINTENANCE OF SPERMATOGENESIS IN RATS IMPLANTED WITH POLYDIMETHYLSILOXANE CAPSULES CONTAINING VARIOUS ANDROGENS
Authors: BERNDTSON W. E. , DESJARDINS C. , EWING L. L. 
Published: December 2008

SUMMARY
Polydimethylsiloxane (PDS) capsules providing surface areas of 50, 75, 100, 200, 400 and 2000 mm2 were filled with testosterone, testosterone cypionate (TC), or testosterone propionate (TP) and were implanted (s.c.) into sexually mature rats for 56 days to determine the efficacy of this mode of androgen administration in suppressing or maintaining spermatogenesis. Rats that received 75 mm2 capsules of TP and 200 mm2 capsules of testosterone or TC were azoospermic and had a 45–50% reduction in testicular weight. Moreover, immunoreactive serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) concentrations declined eightfold below control values, but plasma testosterone titres and the dry weight of the accessory sex glands were not affected (P > 0·10). Conversely, 2000 mm2 capsules of testosterone, TC or TP maintained testicular weight and induced accessory sex gland hypertrophy as well as a five- to eightfold increase in the concentration of plasma testosterone. The relative number of germ cells at stage VII of the cycle of the seminiferous epithelium was not affected (P > 0·15) by 2000 mm2 testosterone capsules even though immunoreactive serum LH and FSH concentrations remained at least eight-fold below control values. Similar implants containing TC or TP maintained germ cell numbers within 83% of control testes. The results establish that PDS capsules releasing 'low' doses of testosterone, TC or TP induce azoospermia without affecting plasma testosterone concentration or accessory sex gland weight, and that similar capsules releasing 'high' doses of testosterone maintained spermatogenesis quantitatively up to and including step 7 of spermiogenesis.
CORRELATION BETWEEN THE EFFECTS OF HORMONES ON THE SYNTHESIS OF DNA IN EXPLANTS FROM INDUCED RAT MAMMARY TUMOURS AND THE GROWTH OF THE TUMOURS
Authors: LEWIS D. , HALLOWES R. C. 
Published: December 2008

SUMMARY
Explants from 32 mammary tumours induced in Sprague—Dawley rats by 9,10-dimethyl-1,2-benzanthracene (DMBA) were maintained in organ culture for up to 48 h. Insulin, corticosterone, prolactin, growth hormone and oestradiol were added to the culture medium in various combinations and their effects on the DNA synthesis of the explants was studied.
DNA synthesis was stimulated by insulin in explants from 30 out of the 32 tumours examined and this group of 30 responsive tumours could be further subdivided. Explants from 16 tumours showed a greater rate of DNA synthesis in medium containing insulin plus corticosterone plus prolactin than in medium containing insulin alone and this higher rate was decreased by oestradiol; this group is referred to as 'prolactin-responsive'. Explants from the remaining 14 tumours did not show a greater rate of DNA synthesis in medium that contained insulin plus corticosterone plus prolactin than in medium containing insulin alone and neither rate was decreased by oestradiol; this group is referred to as 'insulin-responsive'. Explants from two tumours were not stimulated by insulin and these tumours are referred to as 'non-responsive'. After oophorectomy or administration of ergocryptine to tumour-bearing rats, the prolactin-responsive tumours regressed whereas the non-responsive tumours continued to grow. Explants taken from prolactin-responsive tumours 2 weeks after either oophorectomy or administration of ergocryptine were still prolactin-responsive but those taken from insulin-responsive tumours 2 weeks after the same treatment were now also prolactin-responsive. The non-responsive tumours remained non-responsive.
The effects of hormones on the DNA synthesis in vitro of explants from growing DMBA-induced tumours were thus different from those on explants of mammary glands from virgin or pregnant Sprague—Dawley rats. It was concluded that it was possible to predict by organ culture techniques the response in vivo of growing mammary tumours to oophorectomy and ergocryptine administration.
CORTISOL SECRETION RATE, GLUCOSE ENTRY RATE AND THE MAMMARY UPTAKE OF CORTISOL AND GLUCOSE DURING PREGNANCY AND LACTATION IN DAIRY COWS
Authors: PATERSON J. Y. F. , LINZELL J. L. 
Published: December 2008

SUMMARY
Glucose entry rate was measured by primed infusion of [2-3H]glucose, and cortisol secretion rate by infusion of [1,2-3H2]cortisol, in two cows from 142 days before calving to day 287 of lactation. Mammary blood flow and the mammary uptake of glucose and cortisol were also measured.
In late pregnancy, cortisol secretion rate was 8·6 ± 3·17 (s.d.) μg/min and plasma cortisol concentration was 1·8 ± 0·52 μg/l. During parturition in one animal the secretion rate was 92 μg/min and plasma cortisol concentration was 15 μg/l. During lactation the secretion rate (26·4 ± 7·14 μg/min) and plasma cortisol concentration (5·6 ± 0·73 μg/l) were significantly greater than in dry cows. The mammary uptake of cortisol was 3 to 4% of the secretion rate in both dry and lactating cows.
Glucose entry rate was 5·77 ± 2·250 (s.d.) mg/min/kg0·75 in dry cows and there was no significant mammary uptake of glucose. During lactation the glucose entry increased to 9·45 ± 1·881 mg/min/kg0·75. Mammary uptake of glucose was 3·56 ± 1·949 mg/min/kg0·75. The non-mammary utilization of glucose, glucose entry less mammary uptake, was the same for dry and lactating cows.
There was a good correlation between glucose entry and milk yield, and between mammary uptake of glucose and milk yield. Since the mammary arterio-venous glucose concentration difference was relatively constant, it is suggested that the change in mammary blood flow may determine the change in glucose uptake and milk yield.
A NEW AND IMPROVED METHOD FOR THE SEPARATION OF FREE FROM PROTEIN-BOUND PROGESTERONE
Authors: BATRA S. 
Published: December 2008

SUMMARY
A method in which protein-bound and unbound progesterone are separated by filtering the sample through filters of cellulose esters is described. Because of a complete and almost instantaneous separation which is not influenced by pH, temperature and presence of cations or anions, the method lends itself for use in studies on progesterone binding in blood and in cytoplasmic fractions.
CONCENTRATIONS OF IMMUNOREACTIVE THYROTROPHIC HORMONE IN URINE OF NORMAL SUBJECTS, PATIENTS WITH THYROID DISORDERS AND HYPOPITUITARISM, AND AFTER INFUSION OF HUMAN THYROTROPHIC HORMONE
Authors: KUKU S. F. , HARSOULIS P. , YOUNG J. L. , FRASER T. R. 
Published: December 2008

SUMMARY
The urinary excretion of thyroid-stimulating hormone (TSH) has been measured by double antibody radioimmunoassay after concentration by dialysis followed by lyophilization. Among 30 normal subjects, the excretion was 5·6 ± 0·31 (s.e.m.) μu./h. No diurnal variation nor differences between sexes were discerned. In 14 primary hypothyroid subjects the urinary excretion was raised (P < 0·001) to 25·1 ± 3·3 μu./h. In 14 hyperthyroid and 7 hypopituitary subjects subnormal levels of 2·6 ± 0·2 and 2·5 ± 0·22 μu./h (P < 0·001) respectively, were found. Serum and urinary TSH concentrations were measured before, during and after an infusion of human pituitary TSH (MRC 70/9) in two subjects and showed a correlation.
Urinary TSH measurement is thus a good discriminant between normal and hyperthyroid or hypopituitary patients.
CONTROL OF UTERO-OVARIAN VENOUS PROSTAGLANDIN F DURING LABOUR IN THE SHEEP: ACUTE EFFECTS OF VAGINAL AND CERVICAL STIMULATION
Authors: FLINT A. P. F. , ANDERSON ANNE B. M. , PATTEN P. T. , TURNBULL A. C. 
Published: December 2008

SUMMARY
Simultaneous measurements of prostaglandin F, total unconjugated oestrogens and progesterone have been made in utero-ovarian venous or posterior vena caval plasma from pregnant ewes during parturition. In all cases, levels of oestrogens and prostaglandin F increased before delivery, after a decrease in the level of progesterone. In four out of six sheep, during both spontaneous and dexamethasone-induced labour, increases in the levels of oestrogens and prostaglandin F occurred in parallel. In the other two animals, levels of prostaglandin F increased before those of oestrogens. The increases in prostaglandin F consistently preceded any measurable increase in uterine activity, suggesting levels were not raised as a consequence of labour. Infusion of oestrogen to two dexamethasone-treated animals resulted in increased utero-ovarian venous prostaglandin F levels within 2–3 h. These findings support previous evidence indicating that levels of prostaglandin F may be controlled by oestrogen and progesterone. Manual examination of the cervix, with associated distension of the vagina, resulted in dramatic increases in the level of utero-ovarian venous prostaglandin F during the last 13 h of gestation, both in dexamethasone-induced labour and in labour of natural onset. Since expulsion of the foetus also results in vaginal distension, this finding raises the possibility that the very high levels of prostaglandin F observed at delivery may be caused by tactile stimulation of the vagina.
EFFECT OF OXIDATION ON BIOLOGICAL AND IMMUNOLOGICAL ACTIVITY OF PORCINE PARATHYROID HORMONE
Authors: O'RIORDAN J. L. H. , WOODHEAD J. S. , HENDY G. N. , PARSONS J. A. , ROBINSON C. J. , KEUTMANN H. T. , DAWSON B. F. , POTTS J. T. 
Published: December 2008

SUMMARY
The presence of a single methionine in porcine parathyroid hormone, at position 8, permitted assessment of the role of this residue separate from the second methionine residue found at position 18 of bovine and human parathyroid hormones. Oxidation of the solitary methionine of porcine parathyroid hormone to the sulphoxide destroyed biological activity, but this was restored by subsequent reduction with cysteine. Oxidation of the hormone did not, however, affect its immunological activity; therefore, oxidation of the hormone may bring about dissociation of biological and immunological activity.