bluuebunny/crossref_metadata_2025_split huggingface dataset:
AUGMENTATION OF VASOPRESSIN ANTIDIURESIS BY PROLACTIN WITH A NOTE ON THE CONTAMINATION OF INTERNATIONAL STANDARD PROLACTIN
Authors: WATERS A. K. 
Published: December 2008

Department of Physiology, Charing Cross Hospital Medical School, London, W6
(Received 7 April 1977)
It has been reported (Horrobin, Burstyn, Lloyd, Durkin, Lipton & Muiruri, 1971; Buckman & Peake, 1973; Wallin & Lee, 1976) that prolactin affects salt and water metabolism. To assess any interaction of the antidiuretic hormone arginine-vasopressin (AVP) and prolactin, four experiments were performed.
The antidiuretic action of AVP was measured by the standard AVP bioassay method using the water-loaded ethanol-anaesthetized rat described by Jeffers, Livesey & Austin (1942) with the minor modifications of Forsling, Jones & Lee (1968). Male Wistar rats (150-200 g) were used with at least six preparations for each experiment. When stable antidiuretic responses to standard AVP (3rd International Standard, 1957, National Institute for Biological Standards, London) were obtained, the infusion fluid was changed to one containing the appropriate hormone for the experiment and the effect of AVP within the succeeding hour compared
CONCENTRATION OF GONADOTROPHINS IN THE PLASMA AND TESTICULAR RESPONSIVENESS TO GONADOTROPHIC STIMULATION IN ANDROGEN-DEFICIENT C57BL/10J MICE
Authors: BARTKE A. , ROBERSON C. , DALTERIO S. 
Published: December 2008

Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts 01545, U.S.A.
(Received 24 May 1977)
Deficient testicular function was suspected in male C57BL/10J mice from the observations that they have small testes (Shire & Bartke, 1972) and fail to produce the androgen-dependent pregnancy-blocking pheromone (Chapman & Whitten, 1969). Comparison with male DBA/2J mice and several other strains indicated that C57BL/10J mice have fewer spermatogonia, spermatocytes and spermatids, low testicular weight, a progressive decrease in the absolute weight of the testes after sexual maturation, excessive accumulation of esterified cholesterol in the testes and a low level of testosterone in the plasma (Bartke & Shire, 1972; Shire & Bartke, 1972; Bartke, 1974). The relative androgen deficiency of the C57BL/10J mice is also suggested by the observations of Ivanyi (1973), Hill, Clemens, Liu, Vessel & Johnson (1975) and Hoppe (1975).
To define the causes of androgen deficiency in C57BL/10J mice, the levels of gonadotrophins in
A COMPARISON OF PLASMA PROGESTERONE AND LUTEINIZING HORMONE IN GROWING HENS FROM EIGHT WEEKS OF AGE TO SEXUAL MATURITY
Authors: WILLIAMS J. B. , SHARP P. J. 
Published: December 2008

Agricultural Research Council's Poultry Research Centre, King's Buildings, West Mains Road, Edinburgh, EH9 3JS
(Received 20 June 1977)
In the maturing hen the concentration of luteinizing hormone (LH) in the plasma rises to a prepubertal maximum and then declines over a 2–3 week period until the first egg is laid (Sharp, 1975). Sharp (1975) postulated that increased secretion of progesterone by the developing ovary may be responsible for this fall in the level of LH since the large, yolky follicles, which are thought to be steroidogenic (Furr, 1969), develop over a 2–3 week period before the onset of lay (Wilson & Sharp, 1975). The present experiment was designed to test this hypothesis by direct measurement of the amount of progesterone and LH in the blood of growing hens.
Variations in the level of LH in the peripheral plasma were determined by an homologous radioimmunoassay for avian LH (Follett, Scanes &
CHARACTERIZATION AND ASSAY OF THE PROGESTERONE RECEPTOR IN RAT UTERINE CYTOSOL
Authors: VU HAI M. T. , MILGROM E. 
Published: December 2008

SUMMARY
The synthetic progestogen R5020 (17,21-dimethyl-19-norpregna-4,9-diene-3,20-dione) binds with high affinity (Ka = 8·8 × 108 1/mol at 0 °C) to the progesterone receptor from rat uterine cytosol. At nanomolar concentrations, equilibrium is attained in less than 90 min. R5020 has a very low affinity for other specific steroid-binding proteins (corticosteroid-binding globulin and oestrogen receptors) present in relatively high concentrations in the uterine cytosol. The affinity of the receptor for the natural hormone progesterone is remarkably low (Ka= 1 × 108−1·7 × 1081/mol at 0 °C) which explains the instability of progesterone–receptor complexes. Advantage may be taken of this property to remove endogenous progesterone easily by charcoal treatment at 0 °C, a treatment which does not modify the concentration of receptors. A method based on these characteristics is described for the assay of the total number (progesterone-bound and unbound) of receptor sites in uterine cytosol. This assay may be used in various physiological situations where endogenous progesterone is present at unknown concentrations.
PROGESTERONE RECEPTORS IN THE RAT UTERUS: VARIATIONS IN CYTOSOL AND NUCLEI DURING THE OESTROUS CYCLE AND PREGNANCY
Authors: VU HAI M. T. , LOGEAT F. , MILGROM E. 
Published: December 2008

SUMMARY
The concentration of progesterone receptors in rat uterine cytosol and nuclei was measured during the oestrous cycle and pregnancy. The method used allowed the measurement of the total concentration of binding sites (unbound and hormone-bound).
During the oestrous cycle, the concentration of receptors in the cytosol peaked at pro-oestrus, low concentrations were observed at oestrus and metoestrus, and an increase was seen at dioestrus. In the nuclei, maximum concentrations occurred at pro-oestrus and dioestrus. The number of receptors in the cytosol was very low during the first half of pregnancy, but the concentration increased progressively after day 15 to attain a very high level (about 26 000 binding sites/cell) on day 22.
In the nuclei, the concentration of receptors was low at the beginning of pregnancy. On day 5 (day of implantation) there was a slight increase, which corresponded to a decrease in the number of cytosolic receptors and a small peak in the level of progesterone in the plasma. Maximum concentrations were attained during a 'plateau' period between days 9 and 15. Thereafter, there was a decrease in the concentration of nuclear receptors and on day 22, the mean value was very low; in some animals, probably on the verge of parturition, no receptors were detectable in the nuclei.
CIRCADIAN VARIATION IN THE SENSITIVITY OF THE PITUITARY–ADRENAL SYSTEM TO DEXAMETHASONE SUPPRESSION
Authors: DUNN J. D. , CARRILLO A. J. 
Published: December 2008

SUMMARY
Intact female rats were injected with 100 μg dexamethasone/kg body weight or saline at 12.00, 24.00 or 04.00 h. Four hours later, i.e. 16.00, 04.00 or 08.00 h respectively, a double bleeding procedure was used to obtain blood samples from stressed and unstressed rats for subsequent fluorometric determination of corticosterone levels in the plasma. The difference between the level of corticosterone in stressed and unstressed rats (the stress increment) was determined and used as an index of the response of corticosterone in the plasma to stress.
Increments in the levels of corticosterone in the plasma evoked by stress in rats injected at 12.00 h with dexamethasone and bled 4 h later were significantly (P < 0·05) less than those in rats given dexamethasone at 24.00 or 04.00 and bled at 04.00 or 08.00 h respectively. In contrast, stress-induced increments in the level of corticosterone in the plasma of rats treated with saline did not vary with the time of day.
DIURNAL VARIATION IN PLASMA TESTOSTERONE AND CORTISOL IN RHESUS MONKEYS LIVING IN SOCIAL GROUPS
Authors: ROSE R. M. , GORDON T. P. , BERNSTEIN I. S. 
Published: December 2008

SUMMARY
Concentrations of cortisol and testosterone in the plasma of adult male rhesus monkeys living in social groups were determined during a 27-h period. Capture and venipuncture of experienced, conditioned animals did not lead to a fall in the concentration of testosterone in the plasma during the 90 min immediately after removal from the group. Both plasma cortisol and plasma testosterone concentrations showed a significant fall and rise in samples collected every 3 h during a 27-h period, even though there was considerable individual variation. During the autumn breeding season, animals showed higher concentrations of testosterone at both 10.00 and 22.00 h compared with those observed at the same times during the summer. Even though animals demonstrated significant diurnal changes, testosterone samples withdrawn at the same time of day (10.00 h) on consecutive days were significantly correlated with one another (r = 0·65, n = 27, P < 0·01), suggesting the usefulness of sampling once a day to study potential environmental influences on plasma testosterone concentrations.
A CRITICAL PERIOD FOR POSITIVE FEEDBACK IN IMMATURE (21-DAY-OLD) RATS
Authors: PUIG-DURAN E. , MACKINNON P. C. B. 
Published: December 2008

The concentrations of LH and prolactin in the serum in response to a single s.c. injection of oestradiol benzoate (OB, 1 μg) were studied in 21-day-old Wistar rats of different sexual status. In intact female rats, the total concentration of oestrogen in the serum reached a maximum level within 30 min of the injection, whereas the level of LH fell and remained low until a surge occurred 54 h later. However, the amount of prolactin in the serum increased within 1 h of injection of OB and thereafter showed diurnal fluctuations with evening peaks. Male rats castrated within 24 h of birth showed increases in the serum level of both LH and prolactin in response to OB, which were similar in timing to those seen in intact female rats. However, intact male rats failed to show an increase in the level of either LH or prolactin after treatment with OB, while neonatally androgenized female rats, although failing to show an increase in the level of LH, exhibited a prolactin response which was similar to that observed in intact female rats.
A further study was undertaken in rats which had received an initial injection of OB and a subsequent injection of progesterone 5 h before the expected female-type LH surge. In intact female rats, progesterone augmented the oestrogen-stimulated surge of LH, but this effect was not observed in either intact male or neonatally androgenized female rats. In all three groups, however, the level of prolactin in the serum was increased when compared with control animals which had received OB only.
The effect of progesterone, injected at various times after priming with OB, on the output of LH and prolactin was also studied in female rats killed 5 h after the second injection. Up to 21 h after injection of OB, progesterone had no effect on the level of LH or prolactin. If, however, progesterone was then injected during the middle of the light period, but not in the dark period, the concentrations of LH and prolactin increased. Thus there are critical times during a 24 h period when the gonadotrophin output of the oestrogen-primed female rat is responsive to the stimulatory effects of progesterone.
DEGRADATION OF CALCITONIN DURING INCUBATION WITH THYROID SLICES IN VITRO
Authors: PENTO J. T. , ANDERSON C. C. 
Published: December 2008

Division of Pharmacodynamics and Toxicology, College of Pharmacy, 644 Northeast 14th Street, Health Sciences Center, Oklahoma City, Oklahoma 73104, U.S.A.
(Received 30 September 1977)
The secretion of calcitonin in vitro has recently been examined in various mammalian and submammalian species. It appears that calcium and other calcitonin secretagogues produce a much greater secretory response in vivo than in vitro (Bell, 1970; Feinblatt, Raisz & Kenny, 1973; Gautvik & Tashjian, 1974; Selawry, Becker, Bivins, Snider & Silva, 1975). We have previously suggested that the relative unresponsiveness observed in vitro may be due to calcitonin-induced self-inhibition resulting from the accumulation of calcitonin in a closed incubation system in vitro (Orme & Pento, 1976), However, another possible explanation for the secretory unresponsiveness in vitro may be the occurrence of tissue-induced degradation of the secreted calcitonin. Therefore, the present study examined the influence of thyroid tissue from various species on the degradation of calcitonin
LEVELS OF IMMUNOGLOBULINS G AND M AND TRI-IODOTHYRONINE IN CORD BLOOD AND THE DIAGNOSIS OF NEONATAL THYROID DISEASE
Authors: DISSANAYAKE S. 
Published: December 2008

Department of Biochemistry, Faculty of Medicine, Peradeniya Campus, Peradeniya, Sri Lanka
(Revised manuscript received 10 October 1977)
During pregnancy, the level of tri-iodothyronine (T3) in the maternal serum is raised but this increase is not reflected in cord blood (Editorial Comment, 1973; Burke & Eastman, 1974; Walfish, 1976). To what extent the T3 content and the composition of cord blood are interdependent or related is not clear and this study was undertaken to investigate the relationship between the levels of T3 and immunoglobulins in cord blood.
Cord blood was collected from 53 subjects in the General Hospital, Kandy, Sri Lanka, at the time of delivery. Blood samples were allowed to clot and the serum was separated and stored at −20 °C. The concentrations of immunoglobulins G (IgG) and M (IgM) were determined by single radial immunodiffusion in agarose gels (2% for IgG; 1% for IgM) with reference to WHO standard
EFFECTS OF ADRENALECTOMY AND PREDNISOLONE ON THE ABSORPTION AND PHOSPHORYLATION OF THIAMINE IN RATS
Authors: LAZAROV JONCHO 
Published: December 2008

After adrenalectomy, the absorption of [35S]thiamine in the small intestine of rats was significantly reduced. Injection of Δ1,4-pregnadiene-11β,17α,21-triol-3,20-dione (prednisolone) restored this absorption to some extent, but not to the value found in control (unoperated) rats. Treatment with 1% saline had no effect. Adrenalectomy also reduced the amount of [35S]thiamine that accumulated in the intestinal mucosa and liver compared with that found in controls, but treatment with prednisolone increased the retention of thiamine in these tissues. One per cent NaCl raised the retention of thiamine in the liver but not in the mucosa of the jejunum. The loss in body weight that occurred after adrenalectomy was not, however, corrected after treatment with either saline or steroid.
In adrenalectomized rats, the concentrations of thiamine mono- and diphosphates in the intestinal mucosa and the liver were lower than in the control animals. The concentration of thiamine triphosphate was, however, higher in the intestinal mucosa after adrenalectomy, but remained unchanged in the liver. Treatment with prednisolone increased the concentrations of thiamine mono-, di- and triphosphates in both of these tissues in adrenalectomized rats, compared with unoperated control animals.
PITUITARY–THYROID FUNCTION IN THE RHESUS MONKEY (MACACA MULATTA)
Authors: BELCHETZ P. E. , GREDLEY GLENYS , HIMSWORTH R. L. 
Published: December 2008

The mean concentration of thyroxine (T4) in the plasma of the rhesus monkey Macaca mulatta (53 ± 8 (s.d.) nmol/l) is less than the lower limit of the range of concentrations normally found in man; conversely, the mean concentration of tri-iodothyronine (T3) in monkey plasma (2·45 ± 0·52 (s.d.) nmol/l) is at the upper end of the normal human range. The basal concentrations of TSH in the plasma, as measured by radioimmunoassay, were comparable in the two species (mean concentration of TSH in monkey plasma 1·53 mu./l; range 0·2–2·6 mu./l). The administration of radioactive iodine (13–15 mCi Na131I) to these monkeys regularly induced hypothyroidism. The concentration of TSH in the plasma began to rise 3 weeks after the administration of radioactive iodine and reached a maximum and sustained level (30–300 mu./l) after 3 months, at which time the concentrations of T4 and T3 in the plasma were immeasurable. Other pituitary and adrenal functions were unaffected by the hypothyroid state.
Protracted sedation of normal monkeys with phencyclidine hydrochloride resulted firstly within hours in a decline in the concentration of T3 in the plasma without any corresponding alteration in the concentration of T4 and secondly, after 24 h, in a marked rise in the concentrations of both T4 and TSH. The connection between these changes is not clear but phencyclidine does not seem to be a suitable sedative for prolonged studies of the pituitary– thyroid system in normal monkeys. In contrast, sedation with phencyclidine did not affect the concentration of TSH in the plasma of hypothyroid monkeys provided that their body temperature was maintained near normal; the level of TSH fell if the monkey became cold when sedated and rose if it became overheated.
The rise in the level of TSH in the plasma of normal monkeys after administration of synthetic thyrotrophin releasing hormone (TRH) was less than that observed in man, although the effect of the increase upon the plasma T3 concentration was similar in the two species. The response of monkeys to incremental doses of TRH showed that a maximum response was obtained at a lower equivalent dose (1·0 μg/kg body weight) than in man, but administration of this dose (or a greater one) to hypothyroid monkeys caused only small increases in the concentration of TSH in the plasma.
The rapid intravenous injection of 0·2 or 2·0 μg T3 had no effect on the level of TSH in the plasma of hypothyroid monkeys, but 20 μg caused a progressive decline which reached a nadir 35% below the baseline at 5 h; the level of TSH returned to its basal value after 24 h. The raised concentration of TSH in the plasma of hypothyroid monkeys could be reduced to the normal range by the repeated administration of 20 μg T3 over 3 or 4 days.
RELATIONSHIP BETWEEN FOLLICLE-STIMULATING HORMONE, ANDROSTENEDIONE AND OESTRADIOL IN HUMAN FOLLICULAR FLUID
Authors: MCNATTY K. P. , BAIRD D. T. 
Published: December 2008

The concentrations of FSH, oestradiol and androstenedione in the follicular fluid of normal and cystic human follicles were measured at different stages of the menstrual cycle. In addition, the number of granulosa cells in the follicles was determined.
In follicles in which FSH was detectable, the concentration of oestradiol was greater than that of androstenedione, irrespective of the stage of the cycle. In contrast, in those follicles in which FSH was undetectable and in all cystic follicles irrespective of the level of FSH, the concentration of androstenedione was greater than that of oestradiol. In follicles containing FSH there was a highly significant linear correlation between the number of granulosa cells and the concentration of follicular oestradiol (P < 0·001).
It is suggested that in human ovaries up to 90% of the oestradiol in follicular fluid may originate from the granulosa cells.
EFFECTS OF OVARIAN STEROIDS AND PROLACTIN ON THE CONTRACTILITY AND SODIUM PUMP SITE DENSITY OF GUINEA-PIG MYOMETRIUM
Authors: LIPTON A. , LEAH J. , PARKINGTON H. C. 
Published: December 2008

Ovariectomized guinea-pigs were given a single dose of oestrogen or progestogen or the two steroids combined. Controls were given 0·9% saline. Four days after the injection, myometrial contractility in response to spasmogens was measured isometrically in isolated tissue baths, both before and after incubation in Kreb's solution with or without added prolactin. Further myometrial strips were also incubated with or without prolactin and the density of Na+/K+ ATPase 'pump' sites on the surface of the myometrial cell was estimated by labelling with tritiated ouabain.
Incubation with prolactin significantly reduced the contractility of myometrial tissue from guinea-pigs given saline alone, progestogen alone or progestogen plus oestrogen, but not in tissue from animals pretreated with oestrogen. When myometrial strips from animals pretreated with oestrogen or progestogen were incubated without prolactin in the medium, there was a significant increase in the density of pump sites compared with the number in saline-pretreated animals; incubation with prolactin did not further modify this effect. When both steroids were administered together there was a significant increase only when prolactin was present in the incubation medium. There was also a significant increase in the density of pump sites after incubation of myometrium from the control (saline-pretreated) animals in the presence of prolactin.
VASOTOCIN BIOSYNTHESIS BY CULTURED PINEAL GLANDS FROM ADULT MALE RATS
Authors: PAVEL S. , GHINEA ELENA , GOLDSTEIN R. , MATULEVIČIUS V. 
Published: December 2008

Institute of Endocrinology, Bucharest, Romania
(Received 20 September 1977)
We have previously reported that the pineal gland of the mammalian foetus, which comprises mainly specialized secretory ependymal cells (Anderson, 1965), synthesizes the nonapeptide arginine-vasotocin (AVT; Pavel, Dorcescu, Petrescu-Holban & Ghinea, 1973; Pavel, Goldstein, Ghinea & Calb, 1977). However, in contrast with the foetal pineal gland, the predominant cell type in the pineal gland of the adult mammal is the parenchymal cell or pinealocyte (Quay, 1965); there is a marked reduction in the number of ependymal cells and they are restricted to the pineal recess (Anderson, 1965), which shows the same secretory characteristics as the subcommissural organ (Palkovits, 1965). Since we have postulated the ependymal origin of mammalian AVT (Pavel, 1971; Pavel et al. 1973; Pavel, 1975; Pavel et al. 1977), it seemed worthwhile to investigate the synthesis of AVT in the adult pineal gland in order to elucidate, if only
EFFECT OF GLUCOSE AND AMINO ACIDS ON FOETAL RAT PANCREATIC GROWTH AND INSULIN SECRETION IN VITRO
Authors: DE GASPARO M. , MILNER G. R. , NORRIS P. D. , MILNER R. D. G. 
Published: December 2008

SUMMARY
Foetal rat pancreatic rudiments explanted on day 14 of gestation were grown for 6 days in organ culture in medium containing glucose (5·5 or 16·5 mmol/l) and amino acids at the 'physiological' or seven times the 'physiological' concentration. At the end of the period of culture, the rudiments were compared with normal 20-day foetal pancreas for DNA content, insulin concentration and quantitative morphology. The secretion of insulin from the explants was tested during 2 h incubations in medium containing glucose (5·5 or 16·5 mmol/l).
Amino acid, but not glucose enrichment of the culture medium stimulated cellular growth of the rudiment which remained, nevertheless, smaller than that occurring in vivo. All culture conditions produced a smaller proportion of exocrine cells and a greater proportion of β and duct cells than were found in normal 20-day foetal pancreas. Enrichment with amino acids favoured the development of exocrine cells at the expense of duct cells. Glucose had no effect on the development of any type of cell. Enrichment with amino acids resulted in a higher concentration of insulin per β cell but the highest value observed in vitro was only one sixth of that occurring in vivo. The absolute number of β cells cultured in amino-acid-enriched medium was twice that occurring in vivo. Culture in a glucose-enriched medium had no effect on the ability of the explant to respond to an acute glucose challenge during a short incubation, but the basal and glucose-stimulated release of insulin from cultures grown in amino-acid-enriched medium were significantly greater.
EFFECTS OF SUBCUTANEOUS IMPLANTS OF PROGESTERONE ON THE INDUCTION AND DURATION OF SEXUAL RECEPTIVITY IN OVARIECTOMIZED RATS
Authors: HANSEN S. , SÖDERSTEN P. 
Published: December 2008

Ovariectomized rats, pre-implanted with elastomer capsules containing oestradiol, became sexually receptive after exposure to progesterone (implanted in elastomer capsules) for 4–6 h. Implantation of progesterone capsules facilitated receptivity in oestradiol-implanted rats independently of both previous exposure to progesterone implants and the presence of progesterone at the time of implantation.
The duration of sexual receptivity in ovariectomized rats implanted with oestradiol and progesterone capsules was dependent upon the length of both the oestradiol and progesterone capsules, but the decline in sexual behaviour of receptive rats was independent of the continued presence of either oestradiol or progesterone. Repeated implantation of progesterone capsules at 6 hourly intervals prevented the decline of sexual receptivity.