bluuebunny/crossref_metadata_2025_split huggingface dataset:
LEVELS OF OESTROGEN AND PROGESTERONE IN THE PLASMA OF THE RACCOON DOG (NYCTEREUTES PROCYONOIDES) DURING OESTRUS AND PREGNANCY
Authors: VALTONEN MAIJA H. , RAJAKOSKI E. J. , LÄHTEENMÄKI P. 
Published: December 2008

Department of Veterinary Medicine, University of Helsinki, 00170 Helsinki 71, and *Steroid Research Laboratory, Department of Medical Chemistry, University of Helsinki, 00170 Helsinki 17, Finland
(Received 16 September 1977)
Changes in the concentrations of ovarian steroid hormones during oestrus and pregnancy in the dog have recently received much attention by several investigators (Jones, Boyns, Cameron, Bell, Christie & Parkes, 1973; Edqvist, Johansson, Kasström, Olsson & Richkind, 1975; Hadley, 1975a, b). The fox seems to be the only other canine species for which any information on the endocrine changes associated with the oestrous cycle is available (Møller, 1973; Austad, Lunde & Sjaastad, 1976). As part of a study of the reproductive physiology of the raccoon dog Nyctereutes procyonoides (Valtonen, Rajakoski & Mäkelä, 1977), it was decided to investigate the levels of oestradiol-17β and progesterone in the plasma during oestrus and pregnancy.
The six female raccoon dogs used in this study were
CHANGES IN THE LEVELS OF LUTEINIZING HORMONE AND TESTOSTERONE IN THE CIRCULATION OF AGEING MALE RATS
Authors: GRAY G. D. 
Published: December 2008

Department of Physiology, Stanford University School of Medicine, Stanford, California 94305, U.S.A.
(Received 26 September 1977)
Pituitary-testicular function changes substantially with increasing age in male rats; the levels of testosterone and gonadotrophins in the circulation are reduced in old animals (Ghanadian, Lewis & Chisholm, 1976; Riegle & Meites, 1976; Chan, Leathem & Esashi, 1977). However, previous studies compared only young and very old rats (more than 18 months) and the development of age-related changes in the concentrations of testosterone and gonadotrophins has not been examined. Since ageing is a complex interaction of physiological changes over a prolonged period of time, information on the precise timing of the various changes is important in establishing functional relationships in the ageing process. This study investigates hormonal changes in a group of male rats between 8 and 21 months old.
Adult male Long–Evans rats were housed three/cage in a temperature-controlled room with a 14
ANTI-OESTROGENIC EFFECTS OF NAFOXIDINE ON THE SYNTHESIS OF DNA BY THE RAT PITUITARY GLAND
Authors: JACOBI J. M. , LLOYD H. M. 
Published: December 2008

Department of Medicine, University of Queensland, Clinical Sciences Building, Royal Brisbane Hospital, Queensland 4029, Australia
Received 25 October 1977
One of the principal actions of oestrogens on their target organs is stimulation of the synthesis of DNA and cell division. In the rat pituitary gland, anti-oestrogens inhibit the oestrogen-induced increase in weight (Schreiber, Přibyl & Roháčová, 1972) and prevent the rise in the level of serum prolactin induced by oestradiol-17β (Jordan, Koerner & Robinson, 1975). The effects of anti-oestrogens on the synthesis of DNA by the pituitary gland have not been described. The experiments reported here show that the anti-oestrogen nafoxidine completely inhibits the synthesis of DNA and affects the secretion of growth hormone (GH) and prolactin in the male rat.
Male Sprague–Dawley rats, 100 days old, were allowed free access to a pelleted diet and water and were maintained in a controlled environment (12 h light, 12 h darkness).
PROPERTIES OF RAT ADRENAL ZONA RETICULARIS CELLS: PREPARATION BY GRAVITATIONAL SEDIMENTATION
Authors: BELL J. B. G. , GOULD R. P. , HYATT P. J. , TAIT J. F. , TAIT S. A. S. 
Published: December 2008

An enriched fraction of zona reticularis cells was obtained by unit gravity sedimentation of decapsulated adrenal glands from female rats. From light microscopic and ultrastructural studies of the whole gland and the isolated cell fractions, the zona reticularis cells of the adrenal gland can be classified mainly on the bases of size, position and mitochondrial morphology. This cell population consists of two types of cell, the 'true' zona reticularis cells (Type I, modal diameter 9 μm), which usually constitute 90% of the isolated reticularis fraction and 80% of the intact reticularis tissue, and cells (Type II, modal diameter 13 μm) with fasciculata-like properties (rich in lipid and spherical mitochondria with vesicular cristae). Staining of the cell preparation for 3β-hydroxysteroid dehydrogenase activity also demonstrates the existence of two types of cell in the zona reticularis.
The zona reticularis cell fraction, like the zona fasciculata cell fraction, was capable of producing the subsequent steroids from radioactive pregnenolone: corticosterone, deoxycorticosterone, 18-hydroxydeoxycorticosterone, 11-dehydrocorticosterone, progesterone and androstenedione. However, the pattern of steroid production differed markedly between the zona reticularis and zona fasciculata cells, particularly with respect to the production of deoxycorticosterone and corticosterone (and its correlated steroids, 11-dehydrocorticosterone and 18-hydroxydeoxycorticosterone). When R (the ratio of deoxycorticosterone: corticosterone plus 11-dehydrocorticosterone) for the purest preparation of reticularis cells was compared with R for the corresponding preparation of fasciculata cells, the normalized ratio was found to be 6·4, 16·4 and 20·1 in three experiments. The pattern of production of androstenedione per cell was similar in the reticularis and fasciculata cell fractions. The exact mechanism for the altered pattern of steroid metabolism remains to be elucidated. However, these results establish that the corticosteroids produced by the cells of the zona reticularis may be quantitatively, if not qualitatively, different from those produced by the zona fasciculata cells.
ANDROGEN BINDING IN CYTOSOLS AND NUCLEI OF HUMAN BENIGN HYPERPLASTIC PROSTATIC TISSUE
Authors: SIRETT D. A. N. , GRANT J. K. 
Published: December 2008

Androgen binding sites have been detected in cytosols and nuclear extracts from human benign hyperplastic prostatic (BPH) tissue with exchange assays using [3H]methyltrienolone and [3H]5α-dihydrotestosterone respectively. The concentrations of binding sites and the equilibrium dissociation constants for the [3H]steroid–receptor interactions have been determined and the specificity of the binding has been examined. The observed properties of the binding sites are consistent with those characteristic of androgen receptors.
The binding sites are present in nuclear extracts from all BPH tissue samples examined to date. The amount of binding detected in the nuclear fraction is higher than that found in the cytosol.
INSULIN AND GLUCOSE LEVELS IN ACUTE AND CHRONICALLY URAEMIC RATS
Authors: SAEED AMAL M. , EL MUNSHID H. A. , SUKKAR M. Y. , ABDEL WAHAB S. M. 
Published: December 2008

Departments of Physiology and Pathology, Faculty of Medicine, University of Khartoum, P.O. Box 102, Khartoum, Sudan
(Received 31 October 1977)
The important role of the kidney in the degradation and excretion of insulin has recently been reviewed (Rubenstein & Spitz, 1968; Rubenstein, Mako & Horwitz, 1975). The kidney functions with a wide margin of safety but the minimum functional renal mass required for the effective elimination of insulin is not known. The present report deals with the effects of total and five-sixths nephrectomy on the concentrations of insulin and glucose in the blood. The effects of uraemia itself, produced by bilateral ureteric ligation, have also been studied.
Albino rats of the Wistar strain (mean weight 232 ± 5 (s.e.m.) g) were used. Except for ten female rats included in the acutely uraemic group, the remainder of the animals were male. The subsequent operations were performed under open diethyl ether anaesthesia
POSTMATURITY IN THE RAT: HIGH LEVELS OF GLUCAGON IN THE PLASMA OF THE FOETUS AND NEONATE
Authors: PORTHA B. , PICON L. , ROSSELIN G. 
Published: December 2008

*Laboratoire de Physiologie du Développement, Tour 23/33, Université Paris VII, 2 Place Jussieu, 75005 Paris, France and †Unité de Recherches de Diabétologie et d'Etudes Radio-Immunologlques des Hormones Protéiques, U.55 (INSERM), Hôpital Saint-Antoine, 184 Rue du Faubourg Saint-Antoine, 75012 Paris, France
(Received 1 November 1977)
Experimental prolonged gestation in the rat results in a reduction in the amounts of insulin and glucagon accumulated in the pancreas, a low level of insulin in the plasma and a sharp depletion of hepatic glycogen stores (Portha, Rosselin & Picon, 1976). Moreover, in the liver of the postmature foetus the activities of the main glyconeogenic enzymes, glucose-6-phosphatase and phosphoenolpyruvate carboxykinase, are increased (Portha, Le Provost, Picon & Rosselin, 1978). The present study was undertaken to investigate the effects of glucagon in the circulation on these processes.
Gestation was prolonged by s.c. administration of progesterone to the mother (2·5 mg/rat) once daily on days 20·5, 21·5
DEVELOPMENT AND CHARACTERIZATION OF A HOMOLOGOUS RADIOIMMUNOASSAY FOR BOVINE FOLLICLE-STIMULATING HORMONE
Authors: CHENG KWONG-WAH 
Published: December 2008

SUMMARY
A radioimmunoassay for bovine FSH has been developed using a rabbit antiserum against highly purified bovine FSH (160 × NIH-FSH-S1) and a 125I-labelled tracer of the same preparation. The sensitivity was 0·25 ng/ml for purified bovine FSH or 25 ng/ml with reference to a crude bovine FSH (NIH-FSH-B1) standard. Purified bovine LH and TSH showed cross-reactivities of less than 1%, while their subunits and other purified protein hormones showed no significant inhibition at concentrations up to 100 ng/ml. Ovine FSH cross-reacted significantly but in a non-parallel manner; human and rat FSH cross-reacted only slightly. The concentrations of FSH (means ± s.e.m.) in the sera of cows (n = 12), cows at oestrus (4), bulls (7) and steers (9) were measured as 25·4 ± 4·7, 58·4 ± 12·6, 45·7 ± 9·5 and 120·2 ± 36·0 ng/ml respectively. The FSH content of bovine pituitary glands varied greatly between individuals, from 2 to 25 μg/mg tissue. The inhibition curves of pituitary and serum FSH were parallel to that of the bovine FSH standard.
EFFECT OF LOW CALCIUM AND LOW PHOSPHORUS DIETS ON THE INTESTINAL ABSORPTION OF PHOSPHATE IN INTACT AND PARATHYROIDECTOMIZED PIGS
Authors: FOX J. , CARE A. D. 
Published: December 2008

SUMMARY
The intestinal absorption of phosphate has been studied in conscious pigs, each prepared with a Thirty–Vella loop of jejunum. The feeding of diets low in either calcium or phosphorus caused a significant increase in the efficiency of absorption of phosphate from the solution used to perfuse the jejunal loop in both intact and parathyroidectomized (PTX) pigs. An intravenous infusion of parathyroid hormone (0·22 u. kg−1 h−1) into a PTX pig also enhanced the absorption of phosphate. The increase in the absorption of phosphate when the low phosphorus diet was fed was not caused by an increase in the concentration gradient of phosphate ions between the jejunal lumen and blood.
It is concluded that the intestinal absorption of phosphate shows similar changes to those of calcium when diets low in calcium or phosphorus are fed and that parathyroid hormone, although capable of stimulating the absorption of phosphate, is not essential for this adaptation. These effects are probably brought about by changes in the renal production and mucosal uptake of 1,25-dihydroxycholecalciferol, the active metabolite of vitamin D3.
SULPHATION FACTOR (SOMATOMEDIN ACTIVITY) IN EXPERIMENTAL PROTEIN MALNUTRITION IN THE RAT
Authors: SHAPIRO B. , PIMSTONE B. L. 
Published: December 2008

SUMMARY
In a rat model of protein malnutrition in which the failure of growth is a major feature, a low level of bioassayable sulphation factor activity was present in the serum, associated with normal levels of growth hormone and low insulin in the plasma. The administration of pharmacological doses of human or bovine growth hormone did not increase the amount of sulphation factor activity in the serum or the width of the tibial epiphyses in the proteinmalnourished animals. The basal and serum-stimulated incorporation of 35SO42− into the costal cartilages of malnourished animals did not differ from that of controls, which suggests that the responsiveness of the end-organs was normal.
MACROSCOPIC IDENTIFICATION AND STEROIDOGENIC FUNCTION OF ATRETIC FOLLICLES IN SHEEP
Authors: MOOR R. M. , HAY MARY F. , DOTT H. M. , CRAN D. G. 
Published: December 2008

The degree of translucency, vascularization of the follicle wall and the integrity of the membrana granulosa, as seen under a stereoscopic microscope, were used to distinguish between non-atretic and atretic isolated follicles. Subsequent histological evaluation showed that both non-atretic and severely atretic follicles could be correctly identified with over 95% accuracy.
The concentrations of steroids were measured in both follicular tissue and fluid. The total steroid content of large (3·1–6·0 mm diameter) non-atretic follicles in vivo (115 pmol/follicle) exceeded that of large atretic follicles (54 pmol) and also that of small (2·0–3·0 mm diameter) non-atretic and atretic follicles (6 pmol). Oestrogen accounted for 80%, testosterone 13% and progesterone 7% of the total steroid content in large non-atretic follicles, whereas testosterone accounted for 75% of the steroid content in the other three categories of follicles. A similar pattern is observed when the concentrations of steroids are expressed on the basis of follicular weight.
Total oestrogen secretion, as measured by the output of steroid into the culture medium in 24 h, was 937 pmol for large non-atretic, 31 pmol for large atretic, 65 pmol for small nonatretic and 4 pmol for small atretic follicles. In terms of steroid production (pmol/mg tissue), the four follicular categories were equally efficient. However, the type of steroid produced depended on the category of follicle and corresponded to its steroid content.
EFFECTS OF OESTROGEN AND/OR PITUITARY GRAFTS ON NUCLEIC ACID SYNTHESIS IN THE MAMMARY GLANDS OF LACTATING MICE
Authors: NAGASAWA HIROSHI , YANAI REIKO 
Published: December 2008

The mammary gland synthesizes little DNA during lactation in mice. The effects of daily injections of oestradiol benzoate (OB) between days 9 and 11 of lactation, and/or grafting with three isologous anterior pituitary glands on day 1, on the growth of the litter and the development and function of mammary glands were studied on day 12 of lactation in C3H/He mice.
The level of prolactin in the plasma of mice with pituitary grafts was raised, but mammary gland function was not affected. The synthesis and content of mammary gland RNA was depressed after injection of 0·5 μg OB/day; at a dose of 10 μg/day, OB also depressed litter growth and mammary DNA content, but increased the synthesis of DNA and the level of prolactin in the plasma. Pituitary grafting enhanced the effect of 10 μg OB/day on DNA synthesis. These findings suggest that one of the causes of the low level of DNA synthesis in the mammary gland during lactation in mice is a low level of oestrogen in the circulation.
EFFECT OF OVINE LUTEINIZING HORMONE ON THE SECRETION OF PROGESTERONE IN VITRO BY OVARIAN FOLLICLES FROM HYPOPHYSECTOMIZED RATS TREATED WITH FOLLICLE-STIMULATING HORMONE
Authors: LABARBERA A. R. , NOCENTI MERO R. 
Published: December 2008

Department of Physiology, College of Physicians and Surgeons, Columbia University, New York 10032, U.S.A.
(Received 14 November 1977)
Ovarian follicles from oestrous, pro-oestrous and hypophysectomized rats have the capacity to secrete progestins in vitro and to respond to luteinizing hormone (LH) by increasing this secretion (Stoklosowa & Nalbandov, 1972; LaBarbera, Nocenti & Castellano, 1974; Lindner, Tsafriri, Lieberman, Zor, Koch, Bauminger & Barnea, 1974). Follicles from hypophysectomized rats, untreated or treated with follicle-stimulating hormone (FSH), were therefore studied in experiments in vitro to investigate further the gonadotrophic control of progesterone secretion.
Mature virgin female rats (200–250 g) were hypophysectomized and, beginning on day 4 after the operation, received a total of 360 μg ovine FSH (NIH-FSH-S9)/100 g body weight, injected s.c. in corn oil as six divided doses, one every 12 h for 3 days. Untreated controls received corn oil only. On day 7 after hypophysectomy, the ovaries were excised and
EFFECT OF CHRONIC REMOVAL OF TESTICULAR FLUID ON THE RELEASE OF FOLLICLE-STIMULATING HORMONE IN HEMICASTRATED RAMS
Authors: WALTON J. S. , EVINS JANET D. , WAITES G. M. H. 
Published: December 2008

Department of Physiology & Biochemistry, The University, Whiteknights, Reading, RG6 2AJ
(Received 29 November 1977)
Testicular fluid (RTF) collected from rams in this laboratory has been shown to contain 'inhibin', which selectively inhibits the release of follicle-stimulating hormone (FSH) in rats (Franchimont, Chari, Hazee-Hagelstein, Debruche & Duraiswami, 1977). During these collections, the possibility that diversion of RTF from the remaining testis of hemicastrated rams might provide further evidence about the feedback control of FSH was examined.
Eight mature Clun Forest rams, hemicastrated at least 3 months previously, were placed in metabolism crates in a room with natural lighting for 7 days, after which the extratesticular rete of the remaining testis was cannulated (Voglmayr, Scott, Setchell & Waites, 1967) under general anaesthesia. Each ram was returned to its crate, where it was supported by a canvas harness during the collection of RTF (Edwards, Dacheux & Waites, 1976). The operations were performed
A 24 HOUR RADIOIMMUNOASSAY FOR HUMAN PROLACTIN
Authors: GWEE H. M. , MASHITER K. 
Published: December 2008

The Endocrine Unit, Department of Medicine, Royal Postgraduate Medical School, Du Cane Road, London, W12 OHS
(Received 16 December 1977)
Radioimmunoassays for prolactin described previously require incubation periods of 3–8 days (Hwang, Guyda & Friesen, 1971; Sinha, Selby, Lewis & Vanderlaan, 1973; Aubert, Becker, Saxena & Raiti, 1974). In our studies on prolactin secretion by human pituitary adenomas (Mashiter, Adams, Beard & Holley, 1977; Trinder, Barratt, Sood, Holley, van Noorden, Joplin & Mashiter, 1977), we were anxious to obtain assay data more rapidly in order to maximize the experimental life of each preparation. This report describes a 24 h assay which retains the characteristics of our existing 7 day assay with which it is compared.
Human prolactin VLS 1 was used as standard, human prolactin VLS 3 for iodination and rabbit anti-VLS 3 as antiserum, all generously donated by the National Pituitary Agency, NIAMDD, U.S.A. Labelled Na125I (IMS 30) was
SOLUBILIZATION AND PARTIAL CHARACTERIZATION OF HUMAN AND PORCINE THYROTROPHIN RECEPTORS
Authors: DAWES P. J. D. , PETERSEN V. B. , REES SMITH B. , HALL R. 
Published: December 2008

Thyrotrophin (TSH) receptors have been extracted from human and porcine thyroid membranes by treatment with Triton X-100.125I-Labelled bovine TSH was used to monitor receptor activity. Analysis by gel filtration and electrophoresis on acrylamide gels containing sodium dodecyl sulphate suggested that Triton extracts of human thyroid membranes contained TSH receptors with a molecular weight in the region of 50 000 closely associated with Triton micelles of approximate molecular weight 300 000. Isoelectric focusing studies indicated that the Triton-solubilized TSH binding activity had an isoelectric point of pH 4–4·5. The soluble TSH receptors were heat-labile, showed optimum TSH binding at pH 7·4 and reduced hormone binding at high ionic strength. The TSH binding characteristics of membrane-bound and solubilized human TSH receptors were similar and both preparations gave curved Scatchard plots.
Solubilized porcine TSH receptors appeared to have a similar molecular weight to the human receptors and were also closely associated with Triton micelles of approximate molecular weight 300 000. Scatchard analysis of TSH binding to membrane-bound or solubilized porcine TSH receptors gave approximately linear plots with association constants of 2·8 ± 0·95 (s.e.m.) × 109 and 1·7 ± 0·27 × 1091/mol respectively. Comparison of the binding capacities of the solubilized and membrane-bound porcine receptors indicated that the 0·5% Triton extracts contained 40% of the original TSH binding activity and that this was present at a concentration of 25 ng/ml.
POSTOVULATORY LEVELS OF PROGESTOGENS, OESTROGENS, LUTEINIZING HORMONE AND FOLLICLE-STIMULATING HORMONE IN THE PLASMA OF AGED GOLDEN HAMSTERS EXHIBITING A DELAY IN FERTILIZATION
Authors: PARKENING T. A. , SAKSENA S. K. , LAU I. F. 
Published: December 2008

* Department of Anatomy, University of Texas Medical Branch, Galveston, Texas 77550, U.S.A. and †The Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts 01545, U.S.A.
(Received 5 December 1977)
Fertilization is delayed approximately 2–5 h in the majority of ova recovered from aged hamsters (14–17 months old), compared with younger (3–5 months old) animals (Parkening & Soderwall, 1975). This delay may explain the relatively large percentage (40%) of ova which is incapable of developing to the implantation stage in this species (Parkening & Soderwall, 1975). Blaha & Leavitt (1974) have shown that there is a wider variation in the peripheral plasma concentration of progesterone at the time of fertilization in aged than in younger hamsters. A hormonal imbalance in the senescent female hamster may disturb normal gamete interactions, thus causing the delay in fertilization. In order to determine the significance of hormonal levels with respect to fertilization, the concentrations of progestogens,
EFFECTS OF OVARIECTOMY AND TREATMENT WITH PROGESTERONE OR OESTRADIOL-17β ON THE SECRETION OF INSULIN BY THE PERFUSED RAT PANCREAS
Authors: LENZEN S. 
Published: December 2008

Institut für Pharmakologie und Toxikologie, Universität Göttingen, Robert-Koch-Strasse 40, D-3400 Göttingen, Germany
(Received 17 January 1978)
Hyperinsulinaemia caused by female sex hormones has been attributed to increased insulin secretion by the pancreatic β-cells (Costrini & Kalkhoff, 1971; Hager, Georg, Leitner & Beck, 1972), but investigation of this hypothesis has been hampered by methodological difficulties. Treatment of the rat with female sex hormones may affect quantitative and qualitative yields of pancreatic islets after collagenase digestion of the pancreas and may increase the glucose-induced insulin release from the islets when the number of islets, but not the protein content, is chosen as the reference parameter (Costrini & Kalkhoff, 1971). Similarly, treatment with female sex hormones may affect the contamination of pancreatic islets with non-islet cells and therefore alter the islet protein content. Since protein content is used as a reference parameter, values for the rate of release of insulin from the pancreatic