bluuebunny/crossref_metadata_2025_split huggingface dataset:
EFFECTS OF OVARIECTOMY AND OVARIAN HORMONES ON RNA BASE RATIOS IN SPECIFIC RABBIT BRAIN AREAS
Authors: ELEFTHERIOU B. E. , DESJARDINS C. , PATTISON M. L. 
Published: December 2008

SUMMARY
The ribonucleic acid (RNA) base percentages were estimated in the hypothalamus, amygdala, hippocampus, frontal cortex, cerebellum and spinal cord of adult intact female rabbits, and after ovariectomy followed by replacement therapy with oestradiol-17β, progesterone and oestradiol plus progesterone. The results indicate a lack of effect on the spinal cord, but a variable effect on all other brain regions examined. In response to the various treatments, all regions examined produced RNA very rich in guanosine monophosphate indicating synthesis of specific RNA. The hypothalamus showed the most significant overall changes. Progesterone injections resulted in the most persistent effects of the hormonal treatments employed. Hypotheses are proposed to explain the variable hormonal effects on brain RNA base composition. It is suggested that ovarian hormones produce specific molecular changes in nervous tissue related either to 'receptors' for the hormones or to neural functions related to behavioural phenomena which are mediated by these hormones.
HORMONAL REQUIREMENTS FOR THE MAINTENANCE OF OESTRADIOL-INDUCED INHIBITION OF UTERINE SENSITIVITY IN THE OVARIECTOMIZED RAT
Authors: MEYERS K. P. 
Published: December 2008

SUMMARY
Ovariectomized rats treated with 2·5 or 5·0 mg. progesterone daily received a single subcutaneous injection of 0·2 μg. oestradiol on the third day of the progesterone treatment. The deciduomal response to trauma by endometrial scratching was used to determine the degree of uterine sensitivity at various times after oestradiol. Uterine sensitivity was partially and then completely lost 36 and 48 hr. after oestradiol administration. The inhibition of uterine sensitivity persisted until 9 and 11 days after oestradiol when the animals received 2·5 and 5·0 mg. progesterone daily. Uterine sensitivity was completely inhibited on day 11 with doses of oestradiol from 0·2 to 0·05 μg. Withdrawal of progesterone treatment for 48 or 72 hr., but not for 24 hr., after oestradiol treatment restored uterine sensitivity. These results show that the oestradiol-induced inhibition of uterine sensitivity in the progestational endometrium is maintained by continuous progesterone treatment and that the duration of this effect is dependent on the dose of progesterone given.
THE RADIOAUTOGRAPHIC LOCALIZATION OF 125I-LABELLED BOVINE PARATHYROID HORMONE
Authors: DE KRETSER D. M. , MARTIN T. J. , MELICK R. A. 
Published: December 2008

SUMMARY
The distribution and localization of 125I-labelled bovine parathyroid hormone was studied by radioautography in adult rats. The principal site of localization was the proximal convoluted tubule of the kidney. Light and variable localization was present in the liver, but no significant amount of label was found in muscle, spleen, bone or articular cartilage. The localization of this labelled compound in the proximal convoluted tubule suggests that this region degrades 125I-labelled parathyroid hormone.
THE EFFECTS OF PROLONGED STARVATION AND REFEEDING ON 24-HR. URINARY INSULIN LEVELS IN OBESE SUBJECTS
Authors: HELLIER M. D. 
Published: December 2008

SUMMARY
Six obese patients, three men and three women, underwent a period of prolonged total starvation with subsequent refeeding. During starvation 24 hr. urinary insulin excretion fell in five of the six patients, and reached abnormally low values in four. On refeeding there was an immediate rise in urinary insulin excretion in all the patients and in four abnormally high levels were reached. After the initial rise the amounts of urinary insulin again fell despite continued and increasing calorie intake, and in three patients returned to the previously low levels. It is suggested that on refeeding there is preferential release of recently formed 'pro-insulin' from a pancreas depleted of normal insulin stores by starvation, and that restoration of a normal pattern of insulin secretion can occur only after normal pancreatic insulin stores have been repleted. A striking difference in response to starvation was observed between men and women.
PLASMA TESTOSTERONE LEVELS IN MALES WITH THE 47,XYY KARYOTYPE
Authors: PRICE W. H. , VAN DER MOLEN H. J. 
Published: December 2008

SUMMARY
No difference could be demonstrated between the plasma testosterone levels in 17 males with the 47,XYY karyotype and appropriately selected controls.
Significantly higher levels of testosterone were recorded in both 47,XYY and 46,XY males at the maximum security hospital than in males with both karyotypes in other hospitals and in the general population.
ACID PHOSPHATASE ACTIVITY IN VIABLE AND REGRESSING RAT CORPORA LUTEA
Authors: SMITH JEANNE A. , WAYNFORTH H. B. 
Published: December 2008

SUMMARY
Free and total acid phosphatase activity has been measured in individual corpora lutea from rat ovaries in various reproductive states (both natural and experimentally induced). Significant changes both in weight and enzymic activity were found, and an attempt has been made to correlate these with the growth and regression of the corpora lutea. A possible connexion between acid phosphatase activity, progesterone secretion and/or cellular composition of the corpus luteum is suggested.
AFFERENT PATHWAYS OF STRESSFUL STIMULI: CORTICOTROPHIN RELEASE AFTER HYPOTHALAMIC DEAFFERENTATION
Authors: MAKARA G. B. , STARK E. , PALKOVITS M. 
Published: December 2008

SUMMARY
Corticotrophin (ACTH) release induced by stressful stimuli has been studied in rats with completely deafferentated medial basal hypothalamus (MBH) pituitary islands or median eminence (ME)-stalk pituitary islands. The plasma corticosterone level was used as index of ACTH release.
In rats with MBH pituitary islands, capsaicin failed to raise the plasma corticosterone level, but the intraperitoneal administration of E. coli endotoxin, histamine, insulin or a large subcutaneous dose of formaldehyde caused ACTH release which could not be distinguished from that in the controls. Histamine and insulin induced ACTH release even in rats with a ME-stalk pituitary island.
It is suggested that E. coli endotoxin, histamine, insulin hypoglycaemia and large doses of formaldehyde may be classified as 'humoral' stimuli of ACTH release, since a neural afferent input to the MBH is not essential for their action. On the other hand, the integrity of some neural pathways to the MBH is essential for the ACTH-releasing effect of capsaicin.
INFLUENCE OF METHYLTESTOSTERONE AND CYPROTERONE ACETATE ON WOLFFIAN DUCT DIFFERENTIATION IN FEMALE RAT FOETUSES
Authors: ELGER W. , STEINBECK H. , CUPCEANCU B. , NEUMANN F. 
Published: December 2008

SUMMARY
In contrast to results in rabbit and dog foetuses, Wolffian duct stabilization in male rat foetuses was inhibited by cyproterone acetate. On the other hand, the stabilizing effect of methyltestosterone in female rat foetuses could be abolished even when excessive androgen doses were given. The hormonal factor(s) involved in normal Wolffian duct stabilization in male rat foetuses remains to be clarified.
THE MECHANISM OF ACTION OF GONADOTROPHIC HORMONES IN AMPHIBIANS: THE STIMULATION OF Δ5-3β-HYDROXYSTEROID DEHYDROGENASE ACTIVITY IN TESTES OF XENOPUS LAEVIS DAUDIN
Authors: WIEBE J. P. 
Published: December 2008

SUMMARY
The effects of gonadotrophins on the Δ5-3β-hydroxysteroid dehydrogenase (3β-HSD) activity in testes of Xenopus laevis have been determined by histochemical and spectrophotometric methods. Methallibure was employed to inhibit the activity of endogenous pituitary gonadotrophins. Injections of pregnant mare serum gonadotrophin (PMS), human chorionic gonadotrophin (HCG), follicle stimulating hormone (FSH), or luteinizing hormone (LH) resulted in pronounced increases in 3β-HSD activity in the microsomal fraction. PMS was the most stimulatory; the injection of 250 i.u. resulted in an almost ten fold increase in activity. PMS and HCG were more effective than FSH and LH in stimulating 3β-HSD activity and PMS and FSH were more effective than HCG and LH respectively. The increases in activity were inhibited by concomitant injections of actinomycin. 3β-HSD activity was not stimulated directly by gonadotrophins in vitro, but another dehydrogenase or group of dehydrogenases appeared to be activated directly by HCG, FSH and LH but not by PMS. The results are discussed in relation to findings in mammals.
AN EVALUATION OF THE METHOD OF COX FOR THE RAPID ANALYSIS OF PREGNANEDIOL IN URINE BY GAS—LIQUID CHROMATOGRAPHY
Authors: BARRETT SUSAN A. , BROWN J. B. 
Published: December 2008

SUMMARY
Cox's method for the analysis of pregnanediol in human urine by gas—liquid chromatography (GLC) of the free steroid on neopentyl glycol adipate in conjunction with a semi-automatic extractor for processing the urine was evaluated. Without automation of the GLC, one worker could complete 24 assays/day. The reliability of Cox's method was confirmed. Results obtained throughout the menstrual cycle in 15 women, during the pregnancies of 480 patients, in 18 postmenopausal women and in 20 men are presented.
THE ROLE OF OESTROGENS IN SPONTANEOUS OVULATION: EVIDENCE FOR POSITIVE OESTROGEN FEEDBACK IN THE 4-DAY OESTROUS CYCLE
Authors: LABHSETWAR A. P. 
Published: December 2008

SUMMARY
A possible involvement of oestrogens in regulating the ovulatory release of luteinizing hormone (LH) has been explored by using an oestrogenantagonist, clomiphene. When given orally in the afternoon on the day before pro-oestrus to rats with a 4-day cycle, the compound prevented ovulation on the morning of oestrus. This was not associated with interference with vaginal cornification, uterine ballooning or mating. Similarly, clomiphene prevented ovulation in hamsters when given at a corresponding stage of the cycle. In adult rats ovulation could be fully restored by the intravenous administration of LH or LH releasing factor at 14.00 hr. on the day of pro-oestrus. Oestradiol benzoate given simultaneously with clomiphene on the day before pro-oestrus or the stimulus provided by mating on the night of pro-oestrus were also effective in this respect. It is implicit in these findings that clomiphene interferes with ovulation by virtue of its anti-oestrogenicity. This indicates that a positive feedback of oestrogen is an integral part of the chain of events culminating in the ovulatory release of LH in the reproductive cycle.
CORTISOL UTILIZATION BY SALIVARY GLAND, KIDNEY AND ADRENAL CORTEX
Authors: FERGUSON M. M. , GLEN J. B. , MASON D. K. 
Published: December 2008

SUMMARY
Cortisol utilization by salivary glands, kidneys and adrenals of various mammals has been compared by using a standard histochemical technique for the demonstration of hydroxysteroid dehydrogenases. 11β-Hydroxysteroid dehydrogenase activity was localized in salivary gland ducts, renal collecting and convoluted tubules and in the adrenal cortex of some species. There was no obvious relationship between the levels of enzyme activity in the salivary glands, kidneys and adrenals. Neither was the presence of 11β-hydroxysteroid dehydrogenase in salivary glands particularly associated with mucous or serous secretion, nor were sex differences in levels of activity evident.
THE SYNTHESIS OF DNA AND RNA IN NORMAL HUMAN ENDOMETRIUM IN SHORT-TERM INCUBATION IN VITRO AND ITS RESPONSE TO OESTRADIOL AND PROGESTERONE
Authors: NORDQVIST S. 
Published: December 2008

SUMMARY
A method is described for short-term incubations in vitro of normal endometrium for the study of nucleic acid synthesis. Tissue suspensions of specimens obtained at curettage were incubated with and without hormones in a medium consisting of Parker's 199 medium and 20% adult human serum; [3H]thymidine and [14C]uridine were added. The isotope uptake into the nucleic acids was determined and related to the total amount of DNA in each sample. Marked variation in DNA synthesis was noted in endometria obtained at different phases of the menstrual cycle. RNA synthesis varied less. After the addition of progesterone, synthesis of both nucleic acids was reduced. The magnitude of this response varied in different endometria. Thus DNA synthesis in endometria already under strong progesterone influence in vivo (midsecretory phase) was least affected when progesterone was added in vitro.
INTERACTIONS OF OESTRADIOL AND PROGESTINS IN THE MOUSE UTERUS
Authors: MARTIN L. , FINN C. A. 
Published: December 2008

SUMMARY
Progesterone and norgestrel did not inhibit uterine weight increases produced by single injections of oestradiol-17β but reduced those produced by three injections. Histological studies indicate that this anomaly is due to changes in uterine sensitivity to oestradiol, after the first injection of oestradiol.
In ovariectomized animals not receiving a progestin a second or third injection of oestradiol stimulated further increases in stromal and epithelial growth and produced final uterine weights which were large compared with those produced by a single injection.
After pretreatment with a progestin, the first injection of oestradiol produced stromal hypertrophy and hyperplasia but a second and third did not. This is due to a refractory state which develops in the stroma after the first injection, and which is prolonged by the second. Thus the final uterine weights were similar whether single or multiple injections of oestradiol were given.
It is suggested that the anti-oestrogenic effects of progestins in uterine weight assays result from the refractory state induced by oestrogen.
EFFECTS OF VASOPRESSIN, CYCLIC AMP, AND THEOPHYLLINE ON OXYGEN CONSUMPTION OF TOAD BLADDER 'SACS'
Authors: PARISI M. , BENTLEY P. J. 
Published: December 2008

SUMMARY
The oxygen consumption of toad urinary bladders was lower in preparations made up as sacs than in pieces of tissue freely suspended in Ringer solution.
Vasopressin stimulated uptake of oxygen by both types of preparation. This probably reflects facilitated sodium transport from the mucosal to serosal side of the tissue since exclusion of this ion from the fluid bathing the mucosa (inside) abolished this effect.
When water transfer across the bladder is promoted by vasopressin (in the presence of an osmotic gradient; inside hypo-osmotic) there is a reduction (by about 50%) in usage of oxygen. Cyclic AMP had a similar action.
Theophylline and cyclic AMP failed to influence oxygen uptake by pieces of toad bladder tissue freely bathed in sodium—Ringer solution. In preparations made as sacs containing iso-osmotic sodium—Ringer solution the nucleotide stimulated while, paradoxically, the xanthine depressed oxygen consumption. This action of cyclic AMP (like that of vasopressin) is dependent on the presence of sodium at the mucosal side of the tissue since it is not seen in sacs filled with choline—Ringer solution. However, the reduction in O2 consumption produced by theophylline was still seen in the absence of sodium.
INACTIVATION AND DEGRADATION OF PORCINE CALCITONIN BY RAT LIVER, AND RELATIVE STABILITY OF SALMON CALCITONIN
Authors: de LUISE M. , MARTIN T. J. , MELICK R. A. 
Published: December 2008

SUMMARY
Slices and homogenates of a number of rat tissues inactivated porcine calcitonin labelled with 125I; the most active tissue was the liver. Maximal activity was found in rat liver supernatant. The reaction was pH- and dose-dependent, the active principle was non-diffusible, inhibited by p-chloromercuribenzoate and EDTA, and destroyed by heat. Biological activity of calcitonin was lost parallel with the breakdown of the labelled calcitonin (as measured by loss of trichloroacetic acid precipitability). Salmon ultimobranchial calcitonin was much less susceptible to inactivation by rat liver supernatant than the porcine hormone, which may explain the high potency and prolonged action of the salmon hormone in the rat.
DIHYDROTESTOSTERONE IN TESTICULAR TISSUE, AND ITS ANDROGENIC POTENCY IN VIVO
Authors: JEFFCOATE W. J. , SHORT R. V. 
Published: December 2008

SUMMARY
An attempt was made to isolate dihydrotestosterone (5α-androstan-17β-ol-3-one) from samples of testicular tissue taken from a 3-yr-old stallion and a mature bull. The extracts were quantitated by gas—liquid chromatography. In neither case was it possible to detect dihydrotestosterone.
In addition, the androgenic potency of dihydrotestosterone in vivo was compared with that of testosterone. Castrated rats received 14 daily injections subcutaneously of 300 μg of steroid in 0·1 ml arachis oil. After treatment, the rats were killed and the ventral prostates, seminal vesicles and coagulating glands were removed from each rat and weighed. Each gland was subsequently examined histologically. The fructose content of the coagulating glands was measured. The glands taken from rats treated with dihydrotestosterone differed in no way from those of rats treated with testosterone.
OVARIAN FOLLICULAR ACTIVITY IN LATE PREGNANCY
Authors: GOVAN A. D. T. 
Published: December 2008

SUMMARY
A histological study was made of ovaries obtained from patients in the latter half of pregnancy; the duration of pregnancy ranged from 26 to 40 weeks. During the first 7 weeks of this period there was little evidence of follicular activity. From 33 weeks to term new Graafian follicles, rarely exceeding 4 mm in diameter, appeared in progressively increasing numbers. This may be a critical stage in follicular development when the follicle must either go on to complete maturity or suffer atresia. Luteinization of the granulosa layer occasionally occurred in these follicles but it was not accompanied by proliferation of granulosa cells; the surrounding thecal cells frequently showed no sign of luteinization and were sometimes atrophic. The factors responsible for granulosa luteinization seem not to be the same as those necessary for theca luteinization, nor are they identical with the mechanisms responsible for luteal proliferation.
ADRENOCORTICAL FUNCTION IN THE HORSE
Authors: JAMES V. H. T. , HORNER MARIAN W. , MOSS M. S. , RIPPON A. E. 
Published: December 2008

SUMMARY
Evidence for the presence of cortisol and corticosterone in equine plasma and cortisol in equine urine is presented. The mean morning concentration of plasma cortisol was 7 μg/100 ml, and that of corticosterone 0·5 μg/100 ml. A diurnal rhythm of small amplitude was found.
Administration of corticotrophin, induction of hypoglycaemia and surgery produced marked increases in plasma cortisol levels, but only small increases were seen after normal exercise. The changes in plasma cortisol were not invariably accompanied by significant alteration of the eosinophil count.
It is concluded that the mechanisms of control of adrenocortical function in the horse are not dissimilar to those described for other mammalian species.
THE EFFECT OF LOW ENVIRONMENTAL TEMPERATURE ON PLASMA CORTICOSTEROID AND GLUCOSE CONCENTRATIONS IN THE NEWBORN CALF
Authors: KHAN MUSTAQ A. , DICKSON W. M. , MEYERS K. M. 
Published: December 2008

SUMMARY
Exposure of newborn Holstein and Jersey calves to −4 °C did not significantly increase the plasma corticosteroids (cortisol and corticosterone) concentrations compared with calves kept at 16 °C. Two Holstein calves exposed to −12 °C showed a slight decrease of plasma corticosteroid concentrations and one Holstein calf at −18° C responded with a marked increase in both hormones during cold exposure. In the animals at 16 and −4 °C the plasma cortisol and corticosterone concentrations fell steadily during the sampling period. There was also a marked, and almost linear, decrease in the packed cell volume during the sampling period; this occurred in all groups. That this was not due entirely to the withdrawal of blood was shown by a similar decrease in two calves from which only small quantities of blood had been taken. Thus, the decrease in plasma corticosteroids may have resulted to some extent from haemodilution.
An increase in glucose concentration was observed in both the control and cold-exposed calves. There was no correlation between the changes in plasma glucose and plasma corticosteroids.
ROLE OF OESTROGENS AND GONADOTROPHINS IN PERPHENAZINE-INDUCED MAMMOGENESIS
Authors: DANON A. , WELLER C. P. , SULMAN F. G. 
Published: December 2008

SUMMARY
Treatment of intact or recently (1 day) ovariectomized female rats with 5 mg perphenazine (Trilafon)/kg/day for 5 days resulted in marked lobulo—alveolar differentiation of the mammary glands. Perphenazine failed to stimulate mammogenesis in chronically (12 days) ovariectomized rats, unless they had been primed with oestradiol. However, mammogenic effects in chronically ovariectomized rats were obtained after implantation of minute amounts (2 μg) of oestradiol into the median eminence, or after treatment for 16 days with the non-steroid pituitary gonadotrophin-inhibitor methallibure (ICI 33828; 20 mg/kg/day).
Since these latter procedures counteract the gonadotrophin surge after ovariectomy, it would appear that inhibition of gonadotrophin secretion is necessary before prolactin secretion can be stimulated by perphenazine.
Castrated male rats responded to perphenazine with lobulo—alveolar differentiation similar to that in intact males. The implications of this difference with regard to the mechanism of pituitary response to gonadectomy are discussed.
ULTRASTRUCTURE OF THE NEUROHYPOPHYSIS AS SHOWN BY FREEZE-ETCHING
Authors: LIVINGSTON A. 
Published: December 2008

SUMMARY
Freeze-etched preparations of rabbit neurohypophysis and isolated hormone granules from cow neurohypophyses were examined electron microscopically. Many features seen in conventionally prepared sections were also apparent in freeze-etched replicas, particularly the neurosecretory nerve-endings containing elementary granules and elongated pituicyte processes.
Measurements of diameters of both isolated and hormone-containing granules in situ indicated that they were slightly larger in freeze-etched material than in that prepared by conventional electron microscopic techniques.
Fractures through the cores of hormone-containing granules showed a lamellar internal structure of 4 nm periodicity in both species examined.
A STUDY OF PROLACTIN-LIKE ACTIVITY IN INDIVIDUAL HUMAN PITUITARY GLANDS
Authors: NICHOLSON PATRICIA M. 
Published: December 2008

SUMMARY
Polyacrylamide disc gel electrophoresis of aqueous extracts of individual human anterior pituitary glands failed to identify a protein with lactogenic activity which was characteristic of pregnancy and the post-partum period. Lactogenic activity, determined by a semi-quantitative rabbit mammary gland organ culture assay, was largely associated with the growth hormone fraction. The total prolactin activity of individual anterior pituitary glands was determined by a 'local' intradermal pigeon crop sac method. The glands from pregnant and parturient women did not contain a higher concentration of prolactin than those of men or non-pregnant non-lactating women. These results do not provide any evidence for the existence of a human pituitary prolactin distinct from growth hormone. Reasons for this are discussed.
THE EFFECT OF PROMETHAZINE AND CLOMIPHENE ON GONADOTROPHIN SECRETION IN THE RAT
Authors: KOCH Y. , DIKSTEIN S. , SUPERSTINE E. , SULMAN F. G. 
Published: December 2008

SUMMARY
Promethazine and promethazine sulphoxide selectively inhibited gonadotrophin secretion in female rats. The effects obtained were: decrease in ovarian weight, reduction in the number of follicles and corpora lutea in the ovary, prolongation of the oestrous cycle and reduced amounts of gonadotrophin-releasing factors in the hypothalamus.
Very small doses of clomiphene citrate (1–100 ng/kg) increased gonadotrophin secretion in female rats, as shown by an increase in ovarian weight, increase in the number of corpora lutea, shortening of the oestrous cycle and increased amounts of gonadotrophin-releasing factors in the hypothalamus. Higher doses of clomiphene citrate (1 μg—2 mg/kg) produced the well-known inhibition of gonadotrophin secretion.
The possible mechanism of action of these drugs is discussed.