bluuebunny/crossref_metadata_2025_split huggingface dataset:
RELATIONSHIP BETWEEN THE PITUITARY GLAND AND GONADAL STEROIDS: INVOLVEMENT OF A HYPOPHYSIAL FACTOR IN REDUCED α2u-GLOBULIN AND INCREASED TRANSCORTIN CONCENTRATIONS IN RAT SERUM
Authors: VANDOREN G. , VAN BAELEN H. , VERHOEVEN G. , DE MOOR P. 
Published: December 2008

Evidence is presented that the level of α2u-globulin in the serum of male rats depends, at least in part, on neonatal androgens. After castration of adult animals the concentration of this protein falls but remains measurable, whereas in intact or ovariectomized female rats α2u-globulin cannot be detected. Moreover, α2u-globulin is found in adult male and female rats gonadectomized at birth and treated with a single injection of testosterone propionate immediately thereafter. The mechanism by which neonatal androgens increase the concentration of α2u-globulin has been investigated.
Transplantation of a supplementary pituitary gland under the renal capsule of male rats resulted in reduced levels of α2u-globulin and increased levels of transcortin. The changes discussed here were observed only in those animals in which the transplant was functional and they were amplified or reversed by modulators of prolactin secretion such as oestrogens or bromocriptine respectively. The hypothesis is advanced that neonatal androgens stimulate the production of a hypothalamic inhibitory factor that controls the secretion of prolactin, or another hypophysial hormone subjected to similar neuroendocrine control. Measurements in gonadectomized animals and in rats receiving both oestradiol benzoate and bromocriptine indicate that, besides these pituitary-mediated effects, both oestrogens and androgens exert direct effects on the level of α2u-globulin.
GONADOTROPHIC ACTIVITY IN PITUITARY EXTRACTS FROM AN ELASMOBRANCH (SQUALUS ACANTHIAS L.)
Authors: LANCE V. , CALLARD I. P. 
Published: December 2008

Department of Biology, Boston University, Boston, Massachusetts 02215, U.S.A.
(Received 9 January 1978)
Selective ablation of portions of the pituitary gland (Dodd, Evennett & Goddard, 1960) and indirect evidence from heterologous immunohistochemical (Mellinger & Dubois, 1973) or radioimmunoassay (Scanes, Follett & Goos, 1972) data has indicated that the anatomically discrete ventral lobe of the elasmobranch pituitary gland may be the sole source of gonadotrophins in these fishes. Bioassay studies have, however, given conflicting results. With a bioassay involving the uptake of 32P by the testes of 1-day-old chicks, Scanes, Dobson, Follett & Dodd (1972) found gonadotrophic activity only in the ventral lobe, whereas Firth & Vollrath (1973) showed gonadotrophic activity in both the ventral and median lobes of the pituitary gland of Scyliorhinus canicula when using the Xenopus oocyte meiosis assay. Thus there is still no agreement as to the nature and source of the gonadotrophin(s) in elasmobranchs.
The dispersed
ACTIVITY OF TESTOSTERONE 5α-REDUCTASE IN THE HAIR FOLLICLES OF WOMEN WITH POLYCYSTIC OVARIES
Authors: MIYAZAKI MASATOSHI , TAKAYASU SUSUMU , KARAKAWA TAKEHISA , AONO TOSHIHIRO , KURACHI KEIICHI , MATSUMOTO KEISHI 
Published: December 2008

Departments of *Obstetrics and Gynecology and †Dermatology and ‡Institute for Cancer Research, Osaka University Medical School, Fukushima-ku, Osaka 553, Japan
(Received 23 February 1978)
Hirsutism is often seen in patients with polycystic ovaries and it has been suggested that it may be caused by excessive production of androgens or raised concentrations of androgens in the plasma (Kirschner & Bardin, 1972; Kuttenn, Mowszovicz, Schaison & Mauvais-Jarvis, 1977). Hirsutism may also be attributable to altered androgen metabolism in the skin since human skin and its appendages, such as sebaceous glands and hair follicles, are capable of converting testosterone to 17β-hydroxy-5α-androstan-3-one (dihydrotestosterone, DHT) and are considered to be target tissues for androgens (Sansonne & Reisner, 1971; Takayasu & Adachi, 1972; Kuttenn & Mauvais-Jarvis, 1975).
In the present study, the concentration of testosterone in the plasma and the activity of 5α-reductase in the hair follicles of seven patients with polycystic ovaries and definite hirsutism
EVIDENCE FOR THE COMMON IDENTITY OF RABBIT OVARIAN 20α- AND 17β-HYDROXYSTEROID DEHYDROGENASES
Authors: RODWAY R. G. , RAHMAN S. S. 
Published: December 2008

Department of Reproductive Biology, Case Western Reserve University, Cleveland, Ohio 44106, U.S.A.
(Received 21 April 1978)
In recent years, there has been disagreement over the possibility that the activities of the 20α- and 17β-hydroxysteroid dehydrogenases in various endocrine tissues may depend on the same enzymic protein. Contradictory results have been obtained with human placental tissue. The results of Purdy, Halla & Little (1964) and Jarabak & Sack (1969) suggest that the two activities are dependent on the same protein, whereas the data of Karavolas & Engel (1971) suggest that they are not. This paper reports our findings on the problem using rabbit ovarian tissue.
Ovaries containing corpora lutea at random stages of development or regression were obtained from rabbits undergoing ovariectomy in a separate experiment. The complete ovaries were homogenized in 12 ml 0·25 m-sucrose and centrifuged for 30 min at 105 000 g. The supernatant fractions were used for
EFFECTS OF 5α-ANDROSTANE-3β,17β-DIOL AND 5β-DIHYDROTESTOSTERONE ON ACID PHOSPHATASE ACTIVITY IN THE PROSTATE GLAND OF THE CASTRATED ADULT RAT
Authors: TENNISWOOD M. P. , ABRAHAMS PAMELA P. , BIRD C. E. , CLARK A. F. 
Published: December 2008

Polyacrylamide gel electrophoresis of filtrates from adult rat prostatic tissue showed two bands of acid phosphatase activity. These corresponded to the lysosomal and secretory acid phosphatases. After castration the secretory acid phosphatase disappeared. The specific activity of the enzyme increased from the time of castration to a maximum on day 7 before declining steadily, while the percentage inhibition by tartrate of acid phosphatase increased from control levels to a maximum on day 7 and then decreased to a new steady state by day 15. When 5α-androstane-3β,17β-diol was administered i.p. at a dose of 2 mg/day, starting immediately after castration, the secretory acid phosphatase was retained but the percentage inhibition and the specific activity were both raised above control levels. When this steroid was administered daily starting 7 days after castration the secretory acid phosphatase band on the gels returned more rapidly than with the classical androgens, but the percentage inhibition and specific activity were once again raised.
Intraperitoneal administration of 5β-dihydrotestosterone, at a dose of 2 mg/day, did not maintain the secretory acid phosphatase activity which disappeared by day 5. However, the specific activity of acid phosphatase and the percentage inhibition by tartrate were both raised throughout the experiment. If this steroid was given 7 days after castration, the percentage inhibition by tartrate did not respond and fell to the level seen in castrated rats. The specific activity, however, remained significantly above the level found in castrated control rats.
SYNCHRONOUS EPISODIC RELEASE OF CORTISOL IN THE SHEEP
Authors: FULKERSON W. J. 
Published: December 2008

Department of Animal Science and Production, University of Western Australia, Nedlands, Western Australia 6009, Australia
(Received 13 March 1978)
The activity of the adrenal gland is believed to be governed by the secretion of corticotrophin (ACTH) in a positive stimulus/negative feedback equilibrium. There is increasing evidence that in man, the secretion of corticosteroids never actually reaches a steady-state condition and that the circadian rhythm displayed by these hormones in the circulation is therefore the result of a number of secretory episodes over a 24 h period (Hellman, Nakada, Curti, Weitzman, Kream, Roffwarg, Ellman, Fukushima & Gallagher, 1970; Weitzman, Fukushima, Nogeire, Roffwarg, Gallagher & Hellman, 1971). Data presented by McNatty, Cashmore & Young (1972) also raise the possibility that a similar pattern of hormone release may exist in the sheep. However, McNatty et al. (1972) collected samples relatively infrequently and it is hard to define peaks in cortisol concentration. With more
PLASMA CONCENTRATIONS OF GROWTH HORMONE DURING GROWTH IN NORMAL AND TESTOSTERONE-TREATED CHICKENS
Authors: HARVEY S. , SCANES C. G. 
Published: December 2008

Department of Zoology, University of Hull, Hull, HU6 7RX and * Department of Physiology, Rutgers University, New Brunswick, New Jersey 08903, U.S.A.
(Received 9 May 1978)
Recent avian studies (Harvey, Godden & Scanes, 1977; Harvey, Scanes, Falconer, Bolton & Chadwick, 1977) have established a definite pattern of growth hormone (GH) secretion during growth, with high plasma concentrations in young growing birds and low levels in adults. These observations indicate that the concentration of immunoreactive GH in the circulation may be related to the rate of body growth. The aim of the present study was, therefore, to determine whether experimental modification of growth was accompanied by corresponding alterations in GH secretion. Since testosterone suppresses growth in cockerels (Visco, 1973), plasma concentrations of GH were determined during growth in control and testosterone-implanted birds.
Seven 2-week-old cockerels (Thornber 909 strain) were implanted subcutaneously with a testosterone pellet (Intervet, 100 mg) in the nape
EFFECTS OF HIGH ALTITUDE ON ENDOCRINE FUNCTION IN THE SHERPAS OF NEPAL
Authors: BANGHAM C. R. M. , HACKETT P. H. 
Published: December 2008

*National Institute for Biological Standards and Control, Holly Hill, London, NW3 6RB and ‡Himalayan Rescue Association, P.O. Box 283, Kathmandu, Nepal
(Received 23 May 1978)
There is demographic evidence from studies in the Andes (James, 1966; Heer, 1967; Abelson, 1976) for lower fertility in high-altitude dwellers than in moderate- or low-altitude dwellers. In the Sherpas of Nepal, the completed fertility rate at high altitude (about 6·0) is appreciably less than that at lower altitudes (8·5; C. R. M. Bangham & J. M. Sacherer, unpublished observations). However, the physiological reasons (if any) for such a difference are obscure. The present study was carried out to test the hypothesis that such a fertility difference (between low- and high-altitude dwellers) is reflected in different serum concentrations of reproductive hormones.
Sampling was carried out at altitudes of 4240 m in Khumbu, 2670 m in Pharak (south of Khumbu) and 1460 m in Kathmandu; the
SECRETION OF PROGESTERONE DURING GESTATION IN THE RAT
Authors: SANYAL MRINAL K. 
Published: December 2008

The concentrations of progesterone and 5α-pregnane-3,20-dione in ovarian and uterine venous plasma and in the systemic circulation were measured during gestation in the rat. The steroids were quantified by radioimmunoassay after separation on silicic acid microcolumns with the solvent system hexane: ethyl acetate (5: 2, v/v). The concentration of progesterone in the systemic circulation was highest on days 3–4 and 13–17 of pregnancy; throughout gestation, the concentration of 5α-pregnane-3,20-dione was low in relation to that of progesterone and showed no marked changes as gestation proceeded.
The level of progesterone in ovarian venous effluent was 10–20 times higher than that in the uterine vein and 20–50 times greater than that in the systemic circulation. The rate of secretion of progesterone by the ovary was highest during days 13–17 of gestation and ovariectomy during this period markedly reduced the levels of progesterone in the peripheral circulation. The concentration of progesterone in the uterine venous effluent was raised compared with the concentration in plasma from the abdominal aorta, especially on days 7 and 9 of pregnancy.
These results suggest that, in vivo, the rat placenta synthesizes small amounts of progesterone and secretes it into the maternal circulation. The ovary is the primary source of progesterone during pregnancy and the placental contribution is of secondary importance. Although 4-ene-5α-reductase enzyme(s) is present in the ovary and placenta, significant quantities of the reduced progestin 5α-pregnane-3,20-dione are not secreted into the systemic circulation during gestation in the rat.
EVIDENCE FOR SPECIFIC PROGESTERONE RECEPTORS IN RAT BRAIN CYTOSOL
Authors: GREENSTEIN B. D. 
Published: December 2008

Cytosol prepared from rat brains perfused with saline possesses saturable macromolecular components which form unstable complexes with [3H]progesterone in vitro. The components can be distinguished from the serum protein corticosteroid-binding globulin (CBG) which also binds progesterone. Unlike CBG, the cytosol components did not bind corticosterone and were more unstable in the presence of Sephadex LH-20 than was CBG. Furthermore, the components were precipitated by a concentration of ammonium sulphate in which CBG is soluble. Unlabelled progesterone and testosterone competed equipotently with [3H]progesterone, and 5α-pregnane-3,20-dione and deoxycorticosterone competed to a lesser extent, whereas oestradiol, corticosterone and 11β-hydroxy-pregn-4-en-3,20-dione were not bound. Although present in all brain tissues examined and in uterine and anterior pituitary tissue, the saturable binding was not detectable in cytosols from the spleen or diaphragm.
Complete exchange occurred in the incubation at 0 °C between [3H]progesterone and unlabelled progesterone and the saturable binding sites and the reaction attained apparent equilibrium within 2 h at this temperature. An incubation temperature of 30 °C resulted in an almost complete loss of saturable binding. Scatchard plots obtained from binding isotherms were curvilinear and yielded at least three dissociation constants (Kd), two of higher affinity (Kd ≃ 10−8 mol/l) and one about sixty times lower.
From these results it is concluded that rat brain cytosol possesses progesterone-selective components which fulfil some of the criteria required for steroid hormone receptors.
BLOCKAGE OF THE ETHER-INDUCED SURGE OF PROLACTIN BY NALOXONE IN MALE RATS
Authors: SHIN S. H. 
Published: December 2008

Department of Physiology, Abramsky Hall, Queen's University, Kingston, Ontario, Canada, K7L 3N6
(Received 17 July 1978)
It is well established that the stress of ether anaesthesia raises the level of prolactin in the circulation of the rat (Wakabayashi, Arimura & Schally, 1971; Krulich, Hefco, Illner & Read, 1974). Morphine or the endogenous morphine-like peptides, endorphins and enkephalins, can stimulate the secretion of prolactin in vivo (Ojeda, Harms & McCann, 1974; Martin, Audet & Saunders, 1975; Bruni, Van Vugt, Marshall & Meites, 1977; Rivier, Vale, Ling, Brown & Guillemin, 1977; Chihara, Arimura, Coy & Schally, 1978); naloxone, however, blocks the stimulatory effects of these substances (Bruni et al. 1977; Rivier et al. 1977). It was recently demonstrated that naloxone inhibits the secretion of prolactin induced by stress due to heat or immobilization (Van Vugt, Bruni & Meites, 1978). The restraintinduced stress produced an immediate increase in the concentration of prolactin
CIRCANNUAL AND CIRCADIAN RHYTHMS IN THE CONCENTRATION OF CORTICOSTERONE IN THE PLASMA OF THE EDIBLE FROG (RANA ESCULENTA L.)
Authors: DUPONT W. , BOURGEOIS P. , REINBERG A. , VAILLANT R. 
Published: December 2008

For a period of 21 months between May 1974 and September 1976, circadian variations in the plasma concentration of corticosterone were studied by competitive protein-binding techniques in mature male and female edible frogs living in their natural environment. Blood samples were taken from 8 to 12 frogs six times daily and conventional and cosinor methods were used for statistical analysis.
Circadian rhythms were not detected during February and March (time of hibernation). Circannual rhythms were detected in three parameters of the circadian rhythm. The mean concentration of corticosterone over a 24 h period (24 h mean) reached a peak on 1 May (between 15 April and 15 May; 95% limits of confidence); the annual mean value of the 24 h means was 1·97 ± 0·25 (s.e.m.) μg/100 ml, with an amplitude of 0·66 μg/100 ml (0·53–0·79 μg/100 ml; 95% limits of confidence). Circadian variations in the concentration of corticosterone were largest in May (peak of reproductive activity). The time at which the peak concentration of corticosterone occurred showed circannual variations; peak values were detected around 24.00 h in May, 19.00 h in July and 08.00 h in November.
Both circadian and circannual variations have therefore been demonstrated in an endocrine function of an amphibian in its natural habitat.
EXTRACTION OF SMALL AMOUNTS OF OXYTOCIN FROM BIOLOGICAL FLUIDS BY MEANS OF AGAROSE-BOUND NEUROPHYSIN
Authors: ROBINSON I. C. A. F. , WALKER J. M. 
Published: December 2008

The use of agarose-bound neurophysin for the extraction of oxytocin from biological fluids is described. Oxytocin can be extracted from plasma, urine and cerebrospinal fluid with a high rate of recovery and samples varying widely in volume and oxytocin concentration can be tested by the method.
Columns can be used to extract and concentrate dilute samples, or to help identify small amounts of neurohypophysial hormones by affinity chromatography. The oxytocin can be eluted from the column directly into the buffer used for subsequent bioassay. The composition of the final extract is constant and independent of the composition of the sample. The specificity of the binding is high. It is suggested that the method has many advantages over others in current use.
UNOCCUPIED BINDING SITES FOR OESTRADIOL IN NUCLEI FROM HUMAN BREAST CARCINOMATOUS TISSUE
Authors: GEIER A. , GINZBURG R. , STAUBER M. , LUNENFELD B. 
Published: December 2008

The binding of oestradiol to a nuclear fraction extracted from human breast carcinomatous tissue was demonstrated. The material, which was extracted with KCl, sedimented at 3–4S and bound oestradiol with high affinity (dissociation constant ∼ 2 × 10−10 mol/l). Oestriol, diethylstilboestrol and 5α-dihydrotestosterone (100-fold excesses) competed with [3H]oestradiol for the binding sites (binding inhibited by 89 ± 8 (s.d.), 92 ± 6 and 57 ± 8% respectively), whereas progesterone and cortisol (100-fold excesses) did not (binding suppressed by 5 ± 5 and 2 ± 3% respectively). Similar competition patterns were found for cytoplasmic material which bound oestradiol. The binding occurred at 4 °C and was therefore considered to be a measure of the amount of binding material unoccupied by endogenous oestrogen.
Unoccupied binding sites for oestradiol in the nucleus and cytoplasm were measured in 35 samples of breast carcinomatous tissue using sucrose gradient centrifugation. In 17 out of 35 tumours, unoccupied nuclear and cytoplasmic 8S and 4S binding sites could be detected. Three out of 35 tumours contained unoccupied nuclear binding sites and 4S cytoplasmic binding sites. Nuclear binding sites only were found in two out of 35 tumours. Unoccupied nuclear binding sites were not detected in 13 out of 35 tumours and ten of these tumours also did not contain unoccupied cytoplasmic binding sites.
SUPPRESSION OF SERUM LEVELS OF LUTEINIZING HORMONE BY SHORT- AND LONG-LOOP NEGATIVE FEEDBACK IN OVARIECTOMIZED WOMEN
Authors: MIYAKE A. , AONO T. , KINUGASA T. , TANIZAWA O. , KURACHI K. 
Published: December 2008

The suppressive effects of short- and long-loop negative feedback on serum levels of LH were assessed after administration of human chorionic gonadotrophin (HCG) and conjugated oestrogens.
Fourteen ovariectomized women were injected intravenously with 5 mg conjugated oestrogens, eight of these patients were also given an intramuscular injection of 10 000 i.u. HCG 8 h later, while the other six patients were given a control injection of 0·9% saline. The serum levels of LH decreased by similar amounts in both groups of women. Thirteen other ovariectomized women were initially injected with 10 000 i.u. HCG, i.m., seven of these patients were also given an i.v. injection of 5 mg conjugated oestrogens 8 h later, while the remaining six patients received a control injection of 0·9% saline. The results showed that conjugated oestrogens could further suppress the serum level of LH which had been reduced by prior HCG treatment. In six ovariectomized women who received i.m. saline injections at the start of the experiment and 8 h later, the serum levels of LH did not change significantly.
It is concluded that the suppression of the serum concentrations of LH by long-loop negative feedback after administration of 5 mg conjugated oestrogens is greater than that by short-loop negative feedback after treatment with 10 000 i.u. HCG.
EFFECTS OF PINEALECTOMY ON THE SECRETION OF LUTEINIZING HORMONE, TESTOSTERONE AND PROLACTIN IN RAMS EXPOSED TO VARIOUS LIGHTING RÉGIMES
Authors: BARRELL G. K. , LAPWOOD K. R. 
Published: December 2008

Two experiments were carried out to study the effects of controlled lighting régimes on plasma levels of LH, testosterone and prolactin in Romney rams. In the second experiment the rams were either pinealectomized or sham-operated so that the role of the pineal gland in mediating seasonal changes in reproduction could be examined.
Levels of testosterone and prolactin were considerably influenced by the lighting schedule. Peak plasma concentrations of testosterone were associated with periods during which the daily photoperiod decreased, whereas plasma levels of prolactin showed a pattern of changes approximately in phase with the lighting cycles. Mean plasma concentrations of LH were low in all groups of rams, which made the detection of significant effects of any treatment very unlikely. Pinealectomy reduced the effects of changes in the daily photoperiod on the patterns of secretion of testosterone and prolactin. These findings establish the pineal gland as an organ which influences the endocrine responses of rams to photoperiodic stimuli and it is concluded that the pineal gland is probably important as a mediator of seasonal reproductive changes in these animals.
AN EXTRA-ADRENAL ACTION OF ADRENOCORTICOTROPHIN: PHYSIOLOGICAL INDUCTION OF LIPOLYSIS BY SECRETION OF ADRENOCORTICOTROPHIN IN OBESE RABBITS
Authors: LAFONTAN M. , AGID R. 
Published: December 2008

The effect of minor stressful stimuli (saline infusions or venepunctures) on lipid mobilization (estimated by plasma free fatty acids (FFA) and glycerol levels) was studied in two strains of conscious rabbits of various ages. Infusions of 0·9% (w/v) NaCl solution induced a prompt increase of FFA levels in naturally obese rabbits while this effect was absent in younger lighter animals. Administration of propranolol (a β-adrenoceptor blocking drug) beforehand did not prevent lipid mobilization. Adipose tissue in vitro was completely unresponsive to the lipid mobilizing action of adrenaline. The initial output of ACTH induced by stressful stimuli was quickly followed by the increase in the plasma concentration of FFA. A highly significant correlation (r = 0·84 or 0·85; P< 0·01) existed between plasma ACTH and FFA levels 30 and 60 min after the start of stress. Dexamethasone completely prevented lipid mobilization while adipose tissue in vivo and in vitro responded strongly to ACTH. Consequently the lack of response of plasma FFA concentrations in corticosteroid-treated rabbits seemed to be linked to the failure of the pituitary gland to mobilize ACTH rather than to the unresponsiveness of adipose tissue to the pituitary hormone.
Our data indicate that in the rabbit, under conditions of stress, ACTH is of greater physiological importance than catecholamines in the control of lipolysis.