bluuebunny/crossref_metadata_2025_split huggingface dataset:
METABOLIC EFFECTS OF CORTISOL AND CORTICOTROPHINS IN THE AUSTRALIAN BRUSH-TAILED OPOSSUM, TRICHOSURUS VULPECULA (KERR)
Authors: THAN KHIN AYE , McDONALD I. R. 
Published: December 2008

SUMMARY
The effect of cortisol and adrenocorticotrophic hormone (ACTH) administration on indices of carbohydrate, fat and protein metabolism was investigated in the conscious marsupial brush-tailed opossum Trichosurus vulpecula (Kerr).
Short-term (1 h) i.v. infusions of cortisol at 0·02, 0·20 and 1·0 mg/kg/h caused plasma glucose concentration to rise rapidly from the normal range of 106–119 mg/100 ml to 145–163 mg/100 ml at the end of the infusion period without consistent changes in plasma urea, amino acid or free fatty acid (FFA) concentration. Similar infusions of porcine or synthetic ACTH at 0·45 i.u./kg/h increased plasma glucose concentration to similar levels without significant change in plasma urea or amino acid concentration, but with a marked increase in plasma FFA concentration.
Daily injections of 1 mg cortisol acetate/kg for 8 days caused a moderate loss of weight, increased urinary nitrogen excretion and glycosuria in all animals. In one animal it was possible to associate these changes with an increase in plasma cortisol concentration to 8·6 μg/100 ml, and an increase in plasma glucose and urea concentrations to 172 and 52 mg/100 ml, respectively.
Liver glycogen concentrations in normal and 24 h-fasted animals were 5·53 ± 0·73 and 0·20 ± 0·14 g/100 g respectively, and daily i.m. injections of 1 mg cortisol acetate/kg increased the liver glycogen concentration to 3·38 ± 0·63 g/100 g in 24 h-fasted animals.
The erythrocytes contained only small amounts of glucose which increased during cortisol-induced hyperglycaemia.
It is concluded that Trichosurus is highly sensitive to the metabolic effects of glucocorticoids, which resemble those found in eutherian mammals, particularly the rabbit.
NUCLEAR AND CYTOPLASMIC OESTROGEN RECEPTORS IN VAGINAL AND UTERINE TISSUE OF MICE TREATED NEONATALLY WITH STEROIDS AND PROLACTIN
Authors: SHYAMALA G. , MORI T. , BERN H. A. 
Published: December 2008

SUMMARY
Neonatal treatment of female mice with oestrogen or androgen induces persistent vaginal cornification, which may be dependent or independent of ovarian hormones according to the amount administered. The concentration of oestrogen-binding protein in the cytoplasm and in the nuclear fraction was measured in the uterus and vagina of mice treated neonatally with either steroid alone or in combination with prolactin. Vaginal oestrogen responsiveness (dependence) of mice treated with low and high doses of steroids was correlated with oestrogen receptor content. Neonatal treatment with prolactin in combination with the low dosage steroid treatments favoured development of ovary-independent cornification and a concomitant decrease in oestrogen receptors in about 50% of the mice studied.
RELEASE OF 131I FROM THE OVARY OF THE LAYING JAPANESE QUAIL AFTER INJECTION OF PERCHLORATE, THIOCYANATE OR IODIDE
Authors: McLAUGHLIN PAMELA A. , NIRMALAN G. P. , TAM K. H. , ROBINSON G. A. 
Published: December 2008

SUMMARY
Intramuscular injection of KSCN, KClO4 or KI into laying Japanese quail resulted in the discharge of 12·6 to 34·0% of the ovarian 131I within a 1-h measurement period for birds studied 1 to 6 h after labelling. Potassium thiocyanate was as effective as an equimolar quantity of KClO4 in causing this discharge. For birds studied 18 h after labelling, no consistent effect of KClO4, KSCN or KI on ovarian 131I levels was found. Gel, thin-layer and paper chromatography of labelled oocytes determined that > 92% of the 131I was present as inorganic iodide.
CHICK KIDNEY ADENYLATE CYCLASE: SENSITIVITY TO PARATHYROID HORMONE AND SYNTHETIC HUMAN AND BOVINE PEPTIDES
Authors: MARTIN T. J. , VAKAKIS N. , EISMAN J. A. , LIVESEY S. J. , TREGEAR G. W. 
Published: December 2008

SUMMARY
Adenylate cyclase activity of crude plasma membranes from chick kidney was stimulated by low doses of parathyroid hormone (PTH). Sensitivity to PTH was ten to twenty times greater than that of a similar preparation from rat kidney cortex. Synthetic peptides consisting of the NH2-terminal 34 amino acids of bovine PTH (BPTH) and of human PTH (HPTH) were assayed, as were several analogues of these peptides. Bovine PTH (1–34) and HPTH (1–34) were equivalent in their action on chick kidney but the human peptide had only 20% of the activity of the bovine peptide on rat kidney cortex adenylate cyclase. Bovine proPTH ( −6→ + 34) and (Tyr1)-BPTH (1–34) had less activity than BPTH (1–34). Bovine PTH (2–34) inhibited the response to BPTH (1–34). Neither salmon calcitonin nor vasopressin stimulated adenylate cyclase activity.
EFFECT OF CORTISOL ON INSULIN SENSITIVITY OF THE MARSUPIAL BRUSH-TAILED OPOSSUM, TRICHOSURUS VULPECULA (KERR)
Authors: THAN KHIN AYE , McDONALD I. R. 
Published: December 2008

SUMMARY
An investigation was made of the interactions between insulin and cortisol on carbohydrate, fat and protein metabolism in the marsupial brush-tailed opossum Trichosurus vulpecula (Kerr).
Intravenous injection of 0·15 i.u. regular insulin/kg caused a prompt fall in plasma glucose concentration to 33–54% of the control value, in the first 30 min, with complete recovery within 4 h. This was associated with a slow fall in plasma amino acid concentration and a moderate rise in plasma free fatty acid (FFA) concentration. Plasma cortisol concentration was increased 1·5 h after insulin injection to maximum values of 1·24–4·44 μg/100 ml, which were approximately proportional to the degree of hypoglycaemia.
Pretreatment with five daily i.m. injections of 1 mg cortisol acetate/kg caused a marked reduction in insulin sensitivity of three out of four opossums, and increasing the dose to 5 mg/kg caused a similar reduction in insulin sensitivity of the remaining opossum. Cortisol pretreatment raised the control plasma amino acid and FFA concentrations and enhanced the effect of insulin injection on these variables. There was a linear relationship between the control plasma cortisol concentration, within the physiological range, and sensitivity to insulin.
It is concluded that, in contrast to the red kangaroo, the interactions between insulin and glucocorticoids in Trichosurus resemble those reported for eutherian mammals. However, the unusual increase in plasma FFA after insulin injection is unexplained.
EFFECTS OF PREMATURE WEANING ON ADRENAL FUNCTION IN INTACT AND GONADECTOMIZED RATS
Authors: OGLE T. F. , KITAY J. I. 
Published: December 2008

SUMMARY
Premature weaning of intact or gonadectomized male and female rat pups did not alter adrenal function at day 49 provided the level of nutrition was sufficient to prevent loss of body weight. However, when nutrition was limited during the early weaning period (day 16–21) both intact male and female rats exhibited decreased production of corticosterone in vitro. Mechanisms mediating this decreased capacity may differ according to sex. In the male rat, production of total steroids in vitro was decreased as were resting plasma levels of corticosterone, suggesting that the set-point for regulation of corticosterone is altered by diminished adrenocorticotrophic hormone secretion. On the other hand, early weaning of the female did not affect plasma levels of corticosterone or total steroid production in vitro; however, the proportionate production of corticosterone compared with total steroid output in vitro was lowered. This effect could be mediated by depressed plasma levels of luteinizing hormone which obtained in prematurely weaned females whereby a paucity of oestrogen could alter the balance between corticosterone and total steroid production.
NEONATAL ANDROGEN ADMINISTRATION AND AGGRESSION IN THE FEMALE GOLDEN HAMSTER DURING INTERACTIONS WITH MALES
Authors: PAYNE A. P. 
Published: December 2008

SUMMARY
Female golden hamsters received either 300 μg testosterone propionate in oil, or oil alone, on day 1 of life. As adults they were observed in interactions with intact males when (i) intact, (ii) after ovariectomy and (iii) after ovariectomy and treatment with 1 mg testosterone propionate/day. Intact control female hamsters showed normal behaviour for this species by exhibiting more aggression than their male partners. After ovariectomy and subsequent treatment with testosterone propionate the levels of aggression shown by the two sexes became equal. Whilst neonatally androgen-treated females were also more aggressive than the males with which they interacted, they differed from the control females in that their aggressiveness was significantly reduced by ovariectomy and then enhanced by subsequent androgen therapy. When intact and when receiving exogenous androgens, the neonatally androgenized females showed significantly more aggression than the control females.
DAILY CONCENTRATIONS OF GONADOTROPHINS AND PROLACTIN IN THE SERUM OF PREGNANT OR LACTATING HAMSTERS
Authors: BAST J. D. , GREENWALD G. S. 
Published: December 2008

SUMMARY
The concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH) and prolactin in serum at 09.00 h on each day of pregnancy and 9 selected days of lactation in the hamster were determined by radioimmunoassays.
The concentration of FSH on day 1 of the 16-day pregnancy was approximately fivefold greater than the levels on subsequent days. Concentrations of LH decreased on each of the first 3 days of gestation, rose slightly during mid-pregnancy, and then tended to decline during the last trimester. The concentration of prolactin increased approximately twofold from day 1 to day 3, remained elevated until day 8, and then gradually returned during the last half of gestation to the level on day 1. The concentrations of the three hormones on the first 4 days of pregnancy differed markedly from the concentrations during the oestrous cycle.
Parturition had occurred and lactation begun by 09.00 h on day 16 of pregnancy (day 1 of lactation) and the levels of hormone on this day were unchanged from the levels on day 15 of pregnancy. Thereafter, the concentration of FSH increased two- to fourfold while the levels of LH increased until day 3 but then returned to the levels found at day 1. Concentrations of prolactin remained unchanged after day 1 of lactation, except for a decrease on day 2.
EFFECT OF SYNTHETIC LUTEINIZING HORMONE RELEASING HORMONE ON PLASMA LUTEINIZING HORMONE IN THE FEMALE DOMESTIC FOWL, GALLUS DOMESTICUS
Authors: BONNEY ROSEMARY C. , CUNNINGHAM F. J. , FURR B. J. A. 
Published: December 2008

SUMMARY
A dose of 20 μg luteinizing hormone releasing hormone (LH-RH) was injected i.v. into laying hens at different times in relation to ovulation and into immature hens of different ages. In laying hens a small but significant increase in plasma LH was consistently observed similar in height but shorter in duration than the natural pre-ovulatory surge of LH. The response was markedly less than that seen in cockerels injected with LH-RH. The time of injection of LH-RH in relation to ovulation did not affect the response unless it was administered immediately after the pre-ovulatory LH peak, when no release of LH occurred. The release of LH which normally occurs 4–7 h before ovulation was, however, unaffected by a rise in plasma LH stimulated by injection of LH-RH a short time previously. The lack of response to LH-RH in the 3 h before ovulation may be due to a depletion of the pituitary reserve of available LH since the normal pre-ovulatory peak of LH is more prolonged than that induced by LH-RH. In no case was premature ovulation seen after i.v. administration of LH-RH.
After LH-RH injection a striking increase in plasma LH, similar in magnitude to that in the cockerel, was observed in immature hens aged 11 weeks, but the response decreased with age until at 21 weeks, when basal levels of LH had increased, no response occurred. This would appear to be an important modification of the pituitary response to releasing hormone which coincides with the maturation of the hypothalamic-pituitary-gonadal system at the onset of sexual maturity.
PARTURITION IN THE GUINEA-PIG; PLASMA LEVELS OF STEROID HORMONES, STEROID-BINDING PROTEINS, AND OXYTOCIN, AND THE EFFECT OF CORTICOSTEROIDS, PROSTAGLANDINS AND ADRENOCORTICOTROPHIN
Authors: ILLINGWORTH D. V. , CHALLIS J. R. G. , ACKLAND N. , BURTON A. M. , HEAP R. B. , PERRY J. S. 
Published: December 2008

SUMMARY
Parturition in the guinea-pig is not preceded by any consistent change in the maternal plasma concentrations of progesterone, total unconjugated oestrogens or corticosteroids, or by a significant change in the concentration of progesterone-binding globulin (PBG). The onset of parturition was delayed by high doses of oestrogens (stilboestrol and oestradiol), but was not affected by oestriol or an antiserum raised against oestradiol. Premature parturition was achieved by the intra-carotid infusion of adrenocorticotrophin or prostaglandins (PGF2α, PGE2, I.C.I. 80,996) in conscious animals with indwelling catheters. I.C.I. 80,996, a potent analogue of PGF2α, induced parturition in all seven guinea-pigs treated; delivery occurred within 6 h of starting the infusion in six animals, and within 48 h in the seventh. The undesirable side-effects that accompanied treatment with PGF2α or PGE2 were not encountered with I.C.I. 80,996. Parturition induced experimentally resembled normal delivery but was not preceded by any significant change in the maternal levels of progesterone, total unconjugated oestrogens, corticosteroids, PBG or CBG in the circulation. Oxytocin was not detected until the delivery of the first foetus.
Parturition was not induced by maternal or foetal injections of corticosteroids or dexamethasone. Earlier findings are confirmed that the foetal adrenal grows steadily throughout late pregnancy and, unlike the foetal lamb adrenal, undergoes no rapid phase of growth immediately before term. Foetal adrenal weight decreased relative to foetal body weight.
The trigger for parturition in this species remains unidentified.
RELATIONSHIP OF THE SEX OF THE FOETUS TO THE AMOUNT OF HUMAN CHORIONIC GONADOTROPHIN IN PLACENTAE; SINGLE AND DIZYGOTIC TWIN PLACENTAE COMPARED
Authors: HOBSON BRUCE , WIDE LEIF 
Published: December 2008

SUMMARY
Human chorionic gonadotrophin (HCG) was assayed by biological and radioimmunological methods in placentae from 16 women with a normal twin pregnancy. When the concentration and total amount of HCG in placentae was related to the sex of the twin foetus, no significant difference between 'male' and 'female' placentae was found. This is contrary to findings that there is a significant (P < 0·005) difference in the concentration of HCG per g and per placenta of singletons at term. A comparison between the grouped geometric mean data from bioassays shows that the amount of HCG per g and per placenta falls between the geometric mean values for 'male' and 'female' singleton placentae.
CLEARANCE AND METABOLISM OF NEUROPHYSINS BY RAT KIDNEY
Authors: MORRIS B. J. , HUTCHINSON J. S. , JOHNSTON C. I. 
Published: December 2008

SUMMARY
The half-life in the circulation of 125I-labelled porcine neurophysins, injected intravenously into rats, was determined. The radioactivity in blood collected at intervals after injection was characterized as neurophysin by polyacrylamide gel electrophoresis. The half-life of neurophysin I was 1·5 ± 0·1 (s.e.m.) min and that of neurophysin II was 1·7 ± 0·1 min. The metabolic clearance rate of neurophysin I and neurophysin II was 1·9 ± 0·1 and 1·3 ± 0·2 ml/min/200 g respectively. Clearance from the circulation was due to both equilibration with the extravascular space and rapid specific accumulation by the kidney. The neurophysins were filtered at the glomerulus. Most of the neurophysin taken up by the kidney was incorporated into lysosomes, probably in the proximal tubule and degraded to lowmolecular-weight metabolites which appeared in urine and which represented the principal mode of excretion of neurophysins.
DISTRIBUTION OF RADIOACTIVITY IN THE ORGANS OF THE RAT AND MOUSE AFTER INJECTION OF [125I]α-MELANOCYTE-STIMULATING HORMONE
Authors: DUPONT A. , KASTIN A. J. , LABRIE F. , PELLETIER G. , PUVIANI R. , SCHALLY A. V. 
Published: December 2008

SUMMARY
The distribution of radioactivity after intrajugular injection of 125Ilabelled α-melanocyte-stimulating hormone (α-MSH) was studied by whole-body autoradiography of the mouse and by direct measurement of radioactivity in individual organs of the rat. Very high uptake of radioactivity in the pineal gland was measured 5 min after the injection of [125I]α-MSH. Lower levels of accumulation of radioactivity were found in the kidney and in the posterior (including intermediate) lobe of the pituitary. High uptake was also found in the thyroid, stomach, and oesophagus. The specificity of uptake of [125I] α-MSH into the pineal and pituitary is suggested by the very low uptake of Na125I into those tissues.
DISTRIBUTION OF RADIOACTIVITY IN THE ORGANS OF THE RAT AND MOUSE AFTER INJECTION OF l-[3H]PROLYL-l-LEUCYL-GLYCINAMIDE
Authors: DUPONT A. , LABRIE F. , PELLETIER G. , PUVIANI R. , COY D. H. , SCHALLY A. V. , KASTIN A. J. 
Published: December 2008

SUMMARY
The distribution of radioactivity after intrajugular injection of l-[3H]prolyl-l-leucyl-glycinamide has been studied by whole-body autoradiography in the mouse and by direct measurement of radioactivity in individual organs of the rat. There is good agreement between results obtained with the two techniques and animal species. High levels of radioactivity were found in the pineal gland, anterior pituitary, posterior (including intermediate) lobe of the pituitary, and epididymal and brown fat. Lower uptake of radioactivity occurred in the submaxillary gland, kidney, and adrenal gland. The preferential uptake of radioactivity by the pineal gland after injection of the labelled tripeptide suggests a role for this hypothalamic hormone in the control of pineal activity.
A COMPARISON OF THE CHARACTERISTICS OF PARTURITION INDUCED BY PROSTAGLANDIN F2α, INFUSED INTRA-AORTICALLY, WITH THOSE FOLLOWING OVARIECTOMY IN THE RAT
Authors: BUCKLE J. W. , NATHANIELSZ P. W. 
Published: December 2008

SUMMARY
Prostaglandin F2α (PGF2α) was infused intra-aortically at different rates into rats for 11·5 h from day 18 of gestation. At doses in excess of 5 μg/h premature delivery invariably occurred 40–41 h later. At lower doses an all-or-none effect was observed, some animals delivering prematurely and others continuing to term. Parturition could not be induced earlier than 40 h after the start of the treatment even by a continuous infusion of PGF2α, suggesting that the luteolytic role of PGF2α is more important than its oxytocic action in this case.
The rate of fall in plasma progesterone was greater in the rats delivering prematurely than those delivering at term, although the final concentrations of between 15 and 30 ng/ml at delivery were the same.
Labour appeared more normal in the animals receiving PGF2α than in those which had been bilaterally ovariectomized. The possible significance of this in relation to an effect of PGF2α on oestrogen secretion is discussed.
THE INFLUENCE OF SERUM ON THE UPTAKE, CONVERSION AND ACTION OF DIHYDROTESTOSTERONE IN RAT PROSTATE GLANDS IN ORGAN CULTURE
Authors: LASNITZKI ILSE , FRANKLIN HILARY R. 
Published: December 2008

SUMMARY
The influence of serum on the uptake, conversion and action of dihydrotestosterone in relation to the sex steroid binding protein, TeBG, has been investigated in rat ventral prostates in organ culture.
The organs were incubated with [1,2-3H]dihydrotestosterone in: (1) serum-free medium, (2) horse serum, foetal and newborn bovine serum or (3) human male and human pregnancy serum.
With all sera the uptake of dihydrotestosterone fell with rising serum concentration, at first steeply and then more gradually. At the same concentration, the uptake was significantly lower in explants incubated with human pregnancy serum than in those kept with human male serum. The conversion of dihydrotestosterone to androstanediol followed the same pattern and less androstanediol was formed in the presence of pregnancy serum. Since pregnancy serum contains higher amounts of TeBG than male serum, the lowered uptake suggests that only the free hormone was available to the target organ.
Addition of unlabelled dihydrotestosterone resulted in a higher uptake than that measured in explants incubated with the labelled steroid only.
The effect of the human sera on uptake and conversion was correlated with the androgenic activity of dihydrotestosterone applied at physiological concentrations and expressed as the percentage of secretory columnar cells present. The degree of maintenance closely corresponded to the uptake of the hormone. In serum-free medium, the number of columnar cells approached the values found in vivo, with male serum their number, though reduced, was still substantial, with pregnancy serum it was extremely low.
It is concluded that the amounts of TeBG present in serum regulate the supply of the hormone to the target tissue and thus control its biological action.
CONCENTRATIONS OF PROLACTIN IN SERIAL BLOOD SAMPLES FROM GOATS BEFORE, DURING AND AFTER MILKING THROUGHOUT LACTATION
Authors: HART I. C. 
Published: December 2008

SUMMARY
Two experiments are described in which prolactin was measured in (a) serial blood samples taken at monthly intervals (April–November) from six lactating goats before, during and after milking and (b) in similar blood samples taken on days 2, 7 and 12 after parturition. The quantity of prolactin released at milking (April–August) varied both between goats and within the individual goat. No correlation was found between the duration of milking and the quantity of prolactin released into the circulation (r = − 0·24, P > 0·1) or the average concentration of prolactin found at milking (April-August) and the average daily milk yield of the individual goat (r = −0·57, P > 0·1). No evidence was found for a release of prolactin conditioned by events normally preceding milking. The results showed a correlation between the average concentration of prolactin released at milking each month and the average milk yield of the six goats (r = 0·67, P < 0·05). The physiological significance of this correlation is discussed. No correlation was found between the average concentration of prolactin released during early lactation and the average milk yield of the goats (r = 0·36, P > 0·1).
COMPARATIVE EFFECT OF INSULIN ON EXPLANTED ADRENAL MEDULLARY TISSUE AND RAT ADRENAL MEDULLA IN SITU
Authors: PIEZZI R. S. , POHORECKY L. A. , CAVICCHIA J. C. , GALLEANO J. P. 
Published: December 2008

SUMMARY
The adrenal medulla and explanted medullary cells in the anterior chamber of the eye were examined 3 h after the administration of insulin to rats. No alterations were seen in the explanted cells. In the adrenal medulla, light and electron microscopy indicated depletion of adrenaline cells; noradrenaline cells were not affected. Levels of catecholamines were three times higher in the explanted tissue after insulin treatment; in the medulla in situ they declined by 70%. These results confirm that insulin has no direct releasing effect on chromaffin cells.