bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE INTERCONVERSION OF OESTRONE AND OESTRADIOL-17β AND THE CONCENTRATION OF OESTRADIOL-17β RECEPTORS IN CULTURED RABBIT UTERUS
Authors: RUSSELL SUSAN L. , THOMAS G. H. 
Published: December 2008

SUMMARY
The metabolism and uptake of [2,4,6,7-3H]oestrone and [2,4,6,7-3H]oestradiol-17β were examined in explants of rabbit uterus, vagina and skeletal muscle in organ culture for 1 and 3 days. Irrespective of whether the uterus was cultured in the presence of [3H]oestrone or [3H]oestradiol-17β, the tissue contained predominantly [3H]oestradiol-17β. This was also true for vagina, but muscle showed only a limited ability to interconvert the two oestrogens.
The oestradiol-17β binding capacity of cultured uterus was also determined, and was shown to decline rapidly over the first 24 h of culture.
THE PATTERN OF PROGESTERONE SECRETION BY THE AUTOTRANSPLANTED OVARY OF THE EWE IN RESPONSE TO OVINE LUTEINIZING HORMONE
Authors: COLLETT R. A. , LAND R. B. , BAIRD D. T. 
Published: December 2008

SUMMARY
The secretion of progesterone from the autotransplanted ovaries of five ewes was measured by a competitive protein-binding technique. Luteinizing hormone (NIH-LH-S14) increased the secretion rate of progesterone from the ovary when infused for 60 min via the ovarian artery at a rate of 1000 μg/h. The pattern of response in nine experiments was characterized by a significant increase in progesterone secretion which occurred 10–20 min after starting the infusion (150%). Between 30 and 60 min the secretion rate fell progressively towards the control values in spite of the continued infusion of LH. There was a further significant fall in the 30 min following cessation of LH. In three out of nine infusions there was a progressive increase in the ovarian blood flow throughout the infusion with maximal levels being found at the end of the 60-min infusion period.
HUMAN LUTEINIZING HORMONE IN MAN: STUDIES OF METABOLISM AND BIOLOGICAL ACTION
Authors: MARSHALL J. C. , ANDERSON D. C. , FRASER T. RUSSELL , HARSOULIS P. 
Published: December 2008

SUMMARY
Human luteinizing hormone (LH) was given by intravenous infusion to four normal male volunteers. The disappearance of immunoreactive LH from serum followed a single exponential decay, the mean half-life being 136 min. The effect on the testis of the infused LH was variable. Despite high serum LH levels being achieved, only one subject showed a clear increase in circulating 17β-hydroxyandrogen (17-OHA) levels, the other subjects showing little change in the immediate post-infusion period. All subjects had low 17-OHA levels in the period 24–36 h after the infusion. No consistent changes in serum follicle-stimulating hormone levels occurred during or after the infusion.
This suggests that other factors besides LH are necessary to produce maximal testosterone secretion by the testis, and may also be concerned in controlling the diurnal variation of testosterone.
SEQUENTIAL FOETAL—MATERNAL PLASMA CORTISOL LEVELS IN SHEEP
Authors: DROST M. , KUMAGAI L. F. , GUZMAN MARGARET 
Published: December 2008

SUMMARY
Chronic foetal—maternal cortisol interrelationships were studied in five time-dated pregnant ewes. Serial blood samples were obtained from ewe and foetus simultaneously for several weeks before and including parturition. Plasma cortisol was measured by both fluorometry and isotopic competitive protein binding. The data indicate that maternal cortisol levels are slightly higher than those in the foetus during the latter part of gestation until approximately 1 week before parturition. During the last week of gestation, especially 4–5 days before delivery, a marked increase in foetal cortisol levels was noted. Administration of amino-glutethimide to the foetus 1 week before delivery did not alter cortisol levels in either foetus or ewe. The results suggest that parturition in sheep is a culmination of events initiated by active foetal adrenocortical secretion.
INHIBITION OF OVULATION IN THE RAT BY INTRAHYPOTHALAMIC IMPLANTS OF AN ANTIOESTROGEN
Authors: BILLARD ROLAND , McDONALD P. G. 
Published: December 2008

SUMMARY
In order to determine the sites at which oestradiol exerts its positive feed back effect, double-walled cannulae containing the antioestrogen ICI 46,474 were implanted into the preoptic area, median eminence or anterior pituitary. Implants were made at different stages of the cycle and left in place for between 4 and 96 h. Implants in the preoptic area for 24, 48 or 96 h did not significantly inhibit ovulation. Implants placed in the median eminence for 24 h before the critical period significantly inhibited ovulation when compared with controls (P < 0·02). Implantation of antioestrogen in the anterior pituitary for a similar 24-h period was ineffective in blocking ovulation. However, when mixed with cocoa butter and implanted in the anterior pituitary the antioestrogen significantly inhibited ovulation (P < 0·02). The results show that by preventing the action of oestradiol on either the pituitary or the median eminence, ovulation may be inhibited. Ovulation was not affected by implants in the preoptic region which suggests that this area is not involved in the positive feedback action of oestradiol.
STIMULATORY EFFECT OF PROLACTIN ON INCORPORATION OF [3H]THYMIDINE INTO THE URINARY BLADDER OF THE FLOUNDER (KAREIUS BICOLORATUS)
Authors: HIRANO TETSUYA , HAYASHI SEIICHI , UTIDA SEIITIRO 
Published: December 2008

SUMMARY
Administration of prolactin for 3 or 5 days to the seawater-acclimatized flounder, Kareius bicoloratus, resulted in a significant increase in the incorporation of [3H]thymidine into the DNA fraction of the urinary bladder. When isolated bladders were incubated in isotonic Ringer solutions on both mucosal and serosal sides, net movement of water from mucosa to serosa decreased significantly after 3 or 5 daily injections of prolactin, whereas net absorption of sodium ions increased concomitantly; the time-course closely corresponded to that of thymidine incorporation. Tendency toward an increase in [14C]uridine and [3H]leucine incorporation was also observed in the urinary bladder after 5 daily injections of prolactin. However, incorporation of thymidine, uridine and leucine into the intestine was not affected at all by prolactin treatment for 5 days. All three isotopically labelled compounds were incorporated similarly into the urinary bladder and the intestine of control seawater flounders. Cell turnover in the urinary bladder is apparently as rapid as that in the intestine; specific stimulation of cell proliferation by prolactin may be an important factor in the induction of physiological changes in the bladder of the flounder.
A COMPARISON OF PROCEDURES FOR THE ISOLATION OF ADRENOCORTICOTROPHIN FROM HUMAN PITUITARY GLANDS
Authors: THOMAS MARJORIE B. , HARTREE ANNE STOCKELL , KNIGHT R. A. , RATCLIFFE J. G. , FURNIVAL BRIDGET E. 
Published: December 2008

SUMMARY
Two methods for the purification of corticotrophin from human pituitary glands have been assessed by two radioimmunoassays directed towards the C-terminal and N-terminal parts of the molecule, and by bioassay. One procedure, applied to small amounts of tissue, employs acid acetone extraction, oxycellulose adsorption and chromatography on CM-cellulose (CM-23). It is suitable for the small-scale purification of corticotrophin from pituitary glands but the losses associated with extracting low concentrations of hormone suggest that it would be inadequate for application to extrapituitary tissues and tumours. The starting material for the second procedure was a side fraction derived from the large scale extraction of protein hormones from whole pituitary glands. The purification employs oxycellulose adsorption, gel filtration on Sephadex G-50 and chromatography on CM-cellulose (CM-32). It yields sufficient highly potent corticotrophin for use as radioimmunoassay standard while conserving other scarce human pituitary hormones.
INDUCED OVULATION IN ALBINO RATS EXPOSED TO CONSTANT LIGHT
Authors: BROWN-GRANT K. , DAVIDSON J. M. , GREIG FENELLA 
Published: December 2008

SUMMARY
Adult female albino rats were exposed to constant illumination of moderate intensity for 55–65 days; at the end of this period more than 95% had no macroscopically visible luteal tissue in their ovaries and more than 90% were sexually receptive. In these animals ovulation was consistently induced by mating. The major component of the mating pattern responsible for the induction of ovulation was penile intromission. Mounting without intromission was much less effective and the occurrence or non-occurrence of ejaculation did not affect the incidence of ovulation. Non-sexual 'stressful' stimuli or the injection of progesterone also induced ovulation in about 50% of animals. However, adrenal progesterone was not required for either the maintenance of sexual receptivity or mating-induced ovulation since adrenalectomized rats exposed to constant light also mated and ovulated.
The time-course of the secretion of luteinizing hormone (LH), determined by radioimmunoassay of plasma LH, also indicated that mating had effects on LH secretion independent of any action of progesterone. LH concentrations were high at 40 min and maximal at 60 min after mating but decreased thereafter while following the injection of progesterone the levels rose gradually and remained high until at least 360 min after the injection. Sodium pentobarbitone administration had little effect on LH secretion induced by mating but blocked ovulation in some animals. Mating-induced ovulation was not invariably associated with increased activity of the thyroid gland but an increase did occur when the mating stimulus was prolonged.
THE PERSISTENCE OF PROGESTERONE SECRETION IN PREGNANT RATS AFTER HYPOPHYSECTOMY AND HYSTERECTOMY: A COMPARISON WITH PSEUDOPREGNANT, DECIDUOMATABEARING PSEUDOPREGNANT, AND LACTATING RATS
Authors: ROTHCHILD I. , BILLIAR R. B. , KLINE I. T. , PEPE G. 
Published: December 2008

SUMMARY
To test the hypothesis of Raj & Moudgal (1970) that luteinizing hormone (LH) is the essential luteotrophin during pregnancy in the rat, pregnant rats were hypophysectomized and hysterectomized on either day 12 or day 15 of pregnancy, and the changes in peripheral serum progesterone level measured. The serum progesterone level remained at approximately the day-12 value for 3 days after hypophysectomy and hysterectomy on day 12, but fell drastically and remained low after the same operation on day 15, or in pseudopregnant rats operated on on day 12, or after removal of the ovaries from pregnant rats on day 12. Oestrogen treatment increased the serum progesterone level slightly in the pregnant rats after hypophysectomy and hysterectomy, but not after ovariectomy; it had no effect in the pseudopregnant rats, with or without deciduomata, or in lactating rats nursing litters of seven to nine pups.
The corpora lutea stopped growing or slowly regressed soon after hypophysectomy—hysterectomy in all except the pregnant rats operated on on day 12 and treated with oestrogen, and in these growth was very slight. The luteal content of progesterone did not change for 3 days after hypophysectomy—hysterectomy on day 12 of pregnancy, and fell slightly thereafter. The metabolic clearance rate of progesterone was not significantly changed by hypophysectomy—hysterectomy.
It thus appears that true secretion of progesterone continues in pregnant rats for about 3 days after day 12 in the absence of the pituitary and placentas, but at a much lower rate than that found in intact, or in day-12 hypophysectomized pregnant rats (Pepe & Rothchild, 1972a). The placental luteotrophin thus seems to increase the rate of progesterone secretion in the absence of LH. The results do not seem to fit with the hypothesis that LH is essential for progesterone secretion.
ATTACHMENT TO THE LUTEAL PLASMA MEMBRANES: AN EARLY EVENT IN THE ACTION OF LUTEINIZING HORMONE
Authors: RAJANIEMI HANNU , VANHA-PERTTULA TAPANI 
Published: December 2008

SUMMARY
The distribution of 125I-labelled luteinizing hormone (LH) was studied by autoradiography of the murine pregnant ovary 10 min after intravenous administration. The grains in autoradiograms were localized around the luteal cells. The pregnant ovary showed the highest uptake of 125I-labelled LH 30 min after the injection. No similar accumulation of 125I-labelled follicle-stimulating hormone, 125I-labelled albumin or free 125I was obtained. The ribosomal fraction of the corpus luteum contained a slightly higher level of radioactivity than the other subcellular fractions after injection of 125I-labelled LH. Sucrose density gradient centrifugation of the luteal particle preparation resulted in an enrichment of radioactivity in particles containing Na+,K+-activated ATPase, a marker enzyme of the plasma membrane. These findings support the concept of plasma membrane binding as the initial event in LH action on the target tissue.
PREOVULATORY LEVELS OF LUTEINIZING HORMONE, THE CRITICAL PERIOD AND OVULATION IN RATS
Authors: GREIG FENELLA , WEISZ JUDITH 
Published: December 2008

SUMMARY
Plasma levels of luteinizing hormone (LH) were measured by radioimmunoassay in serial samples obtained from unanaesthetized, unrestrained rats by means of intracardiac cannulae (i) in relation to the critical period of neural facilitation (CP) during the afternoon of pro-oestrus and (ii) before and after an injection of sodium pentobarbitone given at specific times in relation to the critical period. Samples were also obtained by cardiac puncture before and after hypophysectomy carried out at specific times in relation to the CP. The effect of pentobarbitone or hypophysectomy on ovulation was also determined in the same animals. The CP as defined by pentobarbitone injection and hypophysectomy lasted from 15.00 to 16.00 h in the majority of rats. During this period the LH levels rose gradually above the basal value, and rose sharply thereafter to reach peak values at 17.00–18.00 h. Pentobarbitone given before the CP delayed the surge by 24 h, while its administration at the end of the CP caused an abrupt fall in plasma LH, indicating a reliance on the neurogenic stimulus both to initiate and to maintain the LH surge. LH levels reached immediately after pentobarbitone administration or hypophysectomy were correlated with the subsequent pattern of ovulation. Only a small increase in LH, amounting to about 14% of the peak values attained during the afternoon of prooestrus, was required for ovulation per se. This amount is similar to the small rise in circulating LH observed during the CP. The bulk of LH secreted during the 'pre-ovulatory surge' does not appear to be required for ovulation.
THE CONCENTRATION OF OESTRONE AND OESTRADIOL-17β IN SPERMATIC VENOUS BLOOD IN MAN
Authors: BAIRD D. T. , GALBRAITH A. , FRASER I. S. , NEWSAM J. E. 
Published: December 2008

SUMMARY
In nine men, spermatic and peripheral venous plasma was collected at operative repair of varicocele or inguinal hernia. The concentrations (ng/100ml plasma ± s.e.m.) of both oestradiol-17β (208 ± 28) and oestrone (36 ± 5) were higher than the corresponding values in peripheral venous blood (oestradiol, 3·2 ± 0·5; oestrone, 7·4 ± 1·5). These results confirm that both oestrogens are secreted directly by the testis.
EFFECT OF STRESS AND ENVIRONMENTAL TEMPERATURE ON ADRENAL FUNCTION IN RANA ESCULENTA
Authors: JURÁNI M. , MURGAŠ K. , MIKULAJ L. , BABUŠÍKOVÁ F. 
Published: December 2008

SUMMARY
The effect of immobilization for 60 min on the adrenal activity of frogs (Rana esculenta) was studied by measuring corticosterone in plasma and corticosterone and catecholamines in adrenorenal homogenates. An increase in plasma corticosterone and in noradrenaline in the adrenorenal homogenate was observed after immobilization for 5 min and there was further increase after prolonged immobilization. However, there was no change throughout the period of immobilization in the corticosterone and adrenaline content of the adrenorenal homogenates. When frogs were exposed to various environmental temperatures the resting plasma corticosterone level did not change at temperatures below 20 °C, but rose significantly at temperatures above 20 °C. No increase in plasma corticosterone concentration occurred at 1 °C after corticotrophin (ACTH) administration. At higher temperatures (up to 30 °C) a significant correlation was found between plasma corticosterone levels after ACTH administration and environmental temperature. No further increase in plasma corticosterone took place at temperatures up to 40 °C. The results indicate a rapid activation of both the interrenal and chromaffin components of the adrenal gland in Rana esculenta when subjected to this type of stress. Changes in plasma corticosterone levels resulting from changes in environmental temperature may be either an expression of specific changes in steroidogenesis of the adrenals, or of the entire metabolic activity of the organism.
THE SEPARATION OF DIFFERENT FORMS OF MELANOCYTE-STIMULATING HORMONE FROM THE RAT NEUROINTERMEDIATE LOBE BY POLYACRYLAMIDE GEL ELECTROPHORESIS, WITH A NOTE ON RAT NEUROPHYSINS
Authors: BAKER BRIDGET I. 
Published: December 2008

SUMMARY
Extracts of rat neurointermediate lobes were subjected to electrophoresis on polyacrylamide gels at both acidic and alkaline pH. Melanocyte-stimulating hormone (MSH) was located in the gels by the Anolis skin method and was associated with bands of stainable material. Three bands with MSH activity were located after electrophoresis on acidic gels and two bands after electrophoresis on alkaline gels. The identity of these bands is discussed. Two further bands on the alkaline gels were associated with neurophysins.
THE PO2, PCO2, pH AND OXYGEN CONTENT OF OVARIAN VENOUS BLOOD OF SHEEP
Authors: BAIRD D. T. , GILES M. , COCKBURN F. 
Published: December 2008

SUMMARY
The PO2, PCO2, pH and oxygen content were measured in blood from the carotid artery, and jugular and ovarian veins of six sheep with cervical ovarian autotransplants. The PO2 in ovarian venous blood (56·0 ± 3·9 (s.e.m.) mmHg) was lower than that in carotid arterial blood (94·3 ± 8·3) but higher than that in jugular venous blood (43·4 ± 3·1). The oxygen content of ovarian venous blood was significantly higher than that of jugular venous blood. The high PO2 and oxygen content in ovarian venous relative to jugular venous blood together with the high blood flow suggests the possibility of arterio-venous shunts within the ovary or its vascular pedicle.
THYROID FUNCTION IN MOLYBDENOTIC RABBITS
Authors: WIDJAJAKUSUMA M. C. R. , BASRUR P. K. , ROBINSON G. A. 
Published: December 2008

SUMMARY
The endocrine activity of the thyroid glands of rabbits fed a diet containing 0·3% molybdate ion for 25 and 31 days was evaluated. Means (± s.e.m.) were plasma thyroxine (T4) concn (μg/100 ml): 15 molybdate-fed rabbits, 2·31 ± 0·34; 19 control rabbits, 4·40 ± 0·34. T4 distribution space (ml/100 g body wt): molybdate-fed rabbits, 21·5±2·1; controls, 21·4 ± 0·9. T4 secretion rate (μg/24 h/100 g): molybdate-fed rabbits, 0·320 ± 0·073; controls, 0·601 ± 0·046. Histometric measurements made on photographs of gland sections showed that the follicular epithelial cells formed 12·8% of the total area in molybdate-fed rabbits and 25·8% in controls. The histological appearance of the sections was one of increased colloidal storage and of epithelial inactivity in the molybdate-fed rabbits. Comparisons with glands from a food-restricted group of rabbits supported the view of thyroidal hypofunction in molybdenosis in rabbits, with reduced food intake as the major causal factor. Some additional degeneration of the thyroid gland was attributed directly to the molybdate ion.
THE INHIBITION BY PROGESTERONE OF UTERINE EPITHELIAL PROLIFERATION IN THE MOUSE
Authors: MARTIN L. , DAS R. M. , FINN C. A. 
Published: December 2008

SUMMARY
Progesterone given at the same time as oestradiol-17β prevented approximately 40% of uterine luminal epithelial cells from entering DNA synthesis, but did not prolong the G1, S or G2 phases in the remainder. However, it blocked the entry of these cells into a second round of DNA synthesis. It is suggested that uterine luminal epithelial cells are only sensitive to progesterone for a limited period in G1.
SEX DIFFERENCES IN GROWTH OF GUINEA-PIGS AND THEIR MODIFICATION BY NEONATAL GONADECTOMY AND PRENATALLY ADMINISTERED ANDROGEN
Authors: SLOB A. K. , GOY R. W. , ten BOSCH J. J. van der WERFF 
Published: December 2008

SUMMARY
One group of animals received androgen prenatally, by daily s.c. injections of 5 mg testosterone propionate (TP) to the doe on days 24 to 41 inclusive of pregnancy, while a second group remained untreated. Some animals of each group were gonadectomized on the day of birth (= day 1) or on day 2. Weight at birth served as a measure of prenatal growth. Comparisons were made between animals born in litters of identical size. Postnatal growth was studied by weighing the animals at 5-day intervals until the age of 130 days. Comparisons were made between groups of animals that were matched for their weights at birth.
At birth males from TP-treated mothers were heavier than their sisters and heavier than control males. After birth, control males grew at faster rates than control females. This difference was not affected by neonatal gonadectomy, but from pubertal age onward the difference decreased and gonadectomized males and females were similar in growth. Female pseudohermaphrodites (from TP-treated mothers), both intact and neonatally ovariectomized, had growth curves similar to those of appropriate male controls at prepubertal ages; at postpubertal ages they were not significantly different from their female counterparts. It is concluded that the sex difference in the rate of prepubertal growth is determined by the absence or presence of androgens before birth, and that the difference in postpubertal growth rate is caused by the stimulatory action of the testes and inhibitory action of the ovaries. It was further found that normal female guinea-pigs have a secondary spurt in growth rate, some time after puberty, whereas in males this was much less clear.
EVIDENCE FOR A TIME DELAY BETWEEN PROLACTIN RELEASE AND THE RESULTING RISE IN MILK SECRETION RATE IN THE RAT
Authors: GROSVENOR C. E. , MENA F. 
Published: December 2008

SUMMARY
The mammary glands of rats either maintained continuously in the animal room on day 14 post partum or isolated in a room without other rats on day 21 post partum, refilled only partially within 8 h after the pups had withdrawn the milk from the glands by suckling with the aid of oxytocin injections to the mother. The partial refilling occurred regardless of whether or not the release of prolactin at the time of suckling was blocked by an injection of an extract of stalk median eminence (SME). The mammary glands of rats not injected with SME continued to refill and reached near capacity within 16 h whereas those of the SME-injected rats failed to refill any further. The glands of the SME-injected rats could be stimulated to refill more completely within 8 h after the initial emptying provided prolactin either was injected or was released endogenously by exposing the mothers to exteroceptive signals from their pups midway during the 8-h period of non-suckling which preceded the initial emptying. More complete mammary refilling also occurred within 8 h if a 4-h rather than an 8-h period of non-suckling preceded the initial emptying of the glands. The results of these investigations indicate that the prolactin released by suckling at the time of the initial emptying of the glands influenced only that milk which reaccumulated in the emptied glands during the 8th—16th h following suckling. The milk which reaccumulated during the first 8 h appeared to be influenced by prolactin released several hours before suckling.
The results suggest, therefore, that a time delay of several hours exists from the time of release of prolactin by suckling until the full stimulatory effect of the hormone upon milk secretion is manifest. Thus the milk secreted after emptying of the glands at a given suckling would be the result of prolactin released earlier either at previous sucklings or in response to exteroceptive stimulation.