bluuebunny/crossref_metadata_2025_split huggingface dataset:
PRODUCTION OF THROMBOXANE B2 BY INTRA-UTERINE TISSUES FROM PREGNANT GOATS IN VITRO
Authors: MITCHELL M. D. , FLINT A. P. F. , KINGSTON E. J. , THORBURN G. D. , ROBINSON J. S. 
Published: December 2008

Nuffield Department of Obstetrics and Gynaecology, University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DU
(Received 9 February 1978)
It has been shown that prostaglandins play an important role in the mechanism of parturition in many species, including the goat (Currie & Thorburn, 1977; Thorburn, Challis & Robinson, 1977). Recently we have demonstrated that intra-uterine tissues from pregnant goats, when superfused in vitro, produce prostaglandins E and F (PGE, PGF) and 13,14-dihydro-15-oxo-prostaglandin F at various rates (Mitchell, Flint, Robinson & Thorburn, 1978). The exciting discoveries of two potent prostaglandin-like compounds, thromboxane A2 (TXA2; Hamberg, Svensson & Samuelsson, 1975) and prostacyclin (PGI2; Moncada, Gryglewski, Bunting & Vane, 1976), have radically altered our thinking on prostaglandins and basic data are urgently required concerning these compounds. Since prostaglandin endoperoxides are the immediate precursors of both prostaglandins and TXA2 (and PGI2) and since TXA2 has been shown to cause contraction of a number
ELIMINATION OF INFUSED ARGININE-VASOPRESSIN AND ITS LONG-ACTING DEAMINATED ANALOGUE IN RATS
Authors: GAZIS DIANA , SAWYER W. H. 
Published: December 2008

SUMMARY
Arginine-vasopressin (AVP) and deamino-arginine-vasopressin (dAVP) were infused into rats. When the concentrations of the two peptides were steady, the rate of clearance of AVP from the plasma was six times the rate of clearance of dAVP. Only 6% of the infused AVP was excreted unchanged in the urine, whereas approximately 100% of the dAVP was excreted. When the infusions were stopped, AVP disappeared from the plasma much more rapidly than dAVP. The plasma concentrations of the two peptides did not decay as simple exponential functions, suggesting that both AVP and dAVP entered a slowly exchanging compartment or compartments during prolonged infusion. These differences in the metabolic clearance of AVP and dAVP may well explain the prolonged antidiuretic effect of dAVP in rats.
THE ROLE OF CORTICOSTERONE IN THE OVULATORY CYCLE OF THE HEN
Authors: SHARP P. J. , BEUVING G. 
Published: December 2008

SUMMARY
This study was undertaken in laying hens to investigate the possibility that a diurnal increase in the concentration of plasma corticosterone is directly responsible for timing the preovulatory surge of LH which results in the first egg of a sequence.
Provided that the ovary contained a mature follicle, i.m. injection of 0·5 or 2·0 but not 0·1 mg corticosterone/kg stimulated a preovulatory release of LH. The dose of 0·5 mg/kg was less effective than that of 2 mg/kg and induced release of LH in only four out of eight hens. However, it resulted in concentrations of plasma corticosterone which were outside the physiological range.
Variations in the concentrations of plasma corticosterone were measured in ten hens on two successive nights for 8·5 h starting at the onset of darkness. The birds were maintained on a lighting regimen of 14 h light/day. The hens were selected so that on the first night there was no preovulatory release of LH while on the second night there was the first preovulatory surge of LH of a sequence starting soon after the onset of darkness. No diurnal increase in the concentration of plasma corticosterone was observed during the first 6 h of darkness on either night nor was any increase seen before the preovulatory release of LH.
These observations suggest that corticosterone is not directly involved in the timing of the first preovulatory surge of LH of a sequence.
FOETAL AND MATERNAL PLASMA CONCENTRATIONS OF 13,14-DIHYDRO-15-OXO-PROSTAGLANDIN F IN THE MARE DURING LATE PREGNANCY AND AT PARTURITION
Authors: BARNES R. J. , COMLINE R. S. , JEFFCOTT L. B. , MITCHELL M. D. , ROSSDALE P. D. , SILVER M. 
Published: December 2008

SUMMARY
The concentrations of 13,14-dihydro-15-oxo-prostaglandin F (PGFM), the stable metabolite of prostaglandin F, were measured in the plasma of catheterized mares and foetuses and non-catheterized thoroughbred mares and ponies during the last months of gestation. The plasma concentration of PGFM increased gradually towards term in all groups of animals. During the operation for insertion of catheters, maternal and foetal concentrations of PGFM were high, but the values fell to basal levels 24–48 h after the operation. It was found that preoperative starvation (24 h) led to a rise in the concentration oef PGFM in th maternal plasma. The raised concentrations of PGFM during the operation were associated with low progestogen and high oestrogen concentrations in umbilical venous plasma. The subsequent survival period of the catheterized foal was inversely related to the maximum concentration of PGFM attained during the operation.
Changes in the plasma concentration of PGFM were studied during normal parturition in thoroughbred mares, during oxytocin-induced delivery in non-catheterized ponies and during premature delivery or abortion in the catheterized animals. The greatest increase in the concentration of PGFM was seen in the thoroughbred animals during second-stage labour; oxytocin also resulted in a very rapid rise in the level of PGFM, which remained high until delivery. In the catheterized animals, the birth of live foetuses was associated with a rise in the concentration of PGFM in both foetal and maternal plasma during the last 2 h before delivery. Less consistent changes were found during abortion.
INHIBIN FROM CULTURES OF RAT SEMINIFEROUS TUBULES
Authors: EDDIE L. W. , BAKER H. W. G. , DULMANIS A. , HIGGINSON R. E. , HUDSON B. 
Published: December 2008

SUMMARY
Medium from cultures of mature rat seminiferous tubules contained a substance which suppressed, in a dose-related manner, the luteinizing hormone releasing hormone (LH-RH)-stimulated secretion of FSH by cultured rat pituitary cells. The secretion of LH was suppressed to a lesser extent and the basal secretion of both LH and FSH was inconsistently affected. Gel filtration on Sephadex G-100 did not fractionate the activity. The active material did not inhibit the secretion of TSH or destroy LH-RH and the activity was not due to testosterone or oestradiol in the medium. Control media from liver cultures were inactive. It is concluded that inhibin is present in media from cultures of rat seminiferous tubules.
EFFECT OF HYPOTENSION INDUCED BY SODIUM NITROCYANOFERRATE (III) ON THE RELEASE OF ARGININE-VASOPRESSIN IN THE UNANAESTHETIZED MONKEY
Authors: FUMOUX F. , CZERNICHOW P. , ARNAULD E. , DU PONT J. , VINCENT J. D. 
Published: December 2008

*I.N.S.E.R.M., U. 176, Laboratoire de Neurophysiologie, Université de Bordeaux II, F. 33076 Bordeaux Cedex, France and †I.N.S.E.R.M., U. 30, Hôpital des Enfants Malades, 149 rue de Sèvres, F. 75015 Paris, France
(Received 17 March 1978)
Haemorrhage is a potent stimulus for the liberation of arginine-vasopressin (AVP) in the unanaesthetized monkey (Arnauld, Czernichow, Fumoux & Vincent, 1977), but in contrast to results obtained with other species, the fall in arterial blood pressure seems to be a more important factor than the reduction in blood volume. However, hypotension induced by haemorrhage varies considerably from one experiment to another, irrespective of the amount of blood withdrawn. In order to control changes in arterial blood pressure more accurately and to study their effect on the release of AVP in the conscious monkey, it was decided to use infusions of sodium nitrocyanoferrate (III), a drug which is known to induce a sustained fall in arterial
MAINTENANCE OF FUNCTIONING HUMAN PITUITARY TUMOURS IN 'NUDE' ATHYMIC MICE
Authors: O'SULLIVAN J. P. , ALEXANDER K. M. , JENKINS J. S. 
Published: December 2008

Departments of Medicine and Histopathology, St George's Hospital Medical School, Cranmer Terrace, London, SW17 ORE
(Received 4 May 1978)
There are now many reports of the growth of various human malignant tumours such as colonic carcinoma and malignant melanoma in the 'nude' athymic mouse (Rygaard & Povlsen, 1969), but there are few instances of human benign tumours being transplanted successfully into these animals. Nevertheless, the possibility of using the 'nude' athymic mouse as a vehicle for maintaining pituitary adenomatous tissue in a viable state for a prolonged period under conditions which are more physiological than those of tissue culture has been examined.
Pituitary adenomas were obtained from seven patients undergoing craniotomy for the treatment of acromegaly and from three patients without acromegaly where the tumour was removed because of visual impairment. Part of the tissue was fixed in formol–saline for light microscopy, part was fixed in 4% glutaraldehyde in phosphate
CONCENTRATIONS OF HYDROGEN IONS, OXYGEN, CARBON DIOXIDE AND BICARBONATE IN PORCINE FOLLICULAR FLUID
Authors: KNUDSEN J. F. , LITKOWSKI L. J. , WILSON T. L. , GUTHRIE H. D. , BATTA S. K. 
Published: December 2008

Department of Physiology and * Division of Nephrology, University of Maryland School of Medicine, Baltimore, Maryland 21201, U.S.A. and †The United States Department of Agriculture, Beltsville, Maryland 20705, U.S.A.
(Received 26 June 1978)
The chemical composition of human ovarian follicular fluid has been well characterized (Shalgi, Kraicer & Soferman, 1972; Edwards, 1974). However, compositional studies of porcine follicular fluid (PFF; Schuetz, 1974; Chang, Jones, Ellefson & Ryan, 1976), have not included acid–base measurements (pH, oxygen and carbon dioxide tension (Po2, Pco2), concentration of bicarbonate HCO3−]). Recent studies of the nuclear maturation of porcine oocytes have demonstrated a rate of maturation of only 55–80% for oocytes collected from ovaries obtained at the abattoir (Tsafriri & Channing, 1975) and it was suggested that maturing and non-maturing oocytes may have undergone nuclear degeneration. It has also been shown in monkeys that oocytes which appear mature when examined by light microscopy may in fact
OVARIAN DEPENDENCE OF THE STIMULATORY EFFECT OF NEONATAL HORMONE TREATMENT ON PLASMA LEVELS OF PROLACTIN IN FEMALE MICE
Authors: NAGASAWA H. , YANAI REIKO , JONES L. A. , BERN H. A. , MILLS KAREN T. 
Published: December 2008

Pharmacology Division, National Cancer Center Research Institute, Tsukiji 5-1-1, Chuo-ku, Tokyo 104, Japan and *Department of Zoology and Cancer Research Laboratory, University of California, Berkeley, California 94720, U.S.A.
(Received 24 April 1978)
Recent studies have demonstrated that neonatal exposure of female mice to oestradiol-17β, testosterone, diethylstilboestrol and 5β-dihydrotestosterone results in increased plasma levels of prolactin in animals as old as 15 months (Yanai, Mori & Nagasawa, 1977; Nagasawa, Mori, Yanai, Bern & Mills, 1978). Treatment with these hormones (Mori, Bern, Mills & Young, 1976; Jones & Bern, 1977; Nagawasa et al. 1978) or with progesterone (Jones & Bern, 1977; Jones, Bern & Wong, 1977) also results in normal and neoplastic stimulation of the mammary gland, which is dependent on the presence of the ovaries. The present communication provides data on plasma levels of prolactin in old female mice treated neonatally with oestradiol or progesterone or both steroids and the effects
CONCENTRATIONS OF 6-OXO-PROSTAGLANDIN F1α AND THROMBOXANE B2 IN THE TRACHEAL FLUID OF FOETAL SHEEP
Authors: MITCHELL M. D. , ROBINSON J. S. 
Published: December 2008

Nuffield Department of Obstetrics and Gynaecology, University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DU
(Received 21 July 1978)
Prostaglandins of the E and F series have been shown to relax or contract respectively guinea-pig trachea and recently it has been demonstrated that the prostaglandin endoperoxides PGG2 and PGH2 (immediate precursors of prostaglandins E and F) have far greater potency in contracting tracheal smooth muscle than prostaglandin F (Hamberg, Svensson, Hedqvist, Strandberg & Samuelsson, 1976). Furthermore, both thromboxane A2 and prostacyclin can also elicit contraction of the trachea with thromboxane A2 being considerably more active (Omini, Moncada & Vane, 1977; Svensson, Strandberg, Tuvemo & Hamberg, 1977). Administration of thromboxane A2 has been shown to raise the tracheal insufflation pressure in guinea-pigs (Svensson et al. 1977) and indeed its stable metabolite thromboxane B2 is released in relatively large amounts from sensitized guinea-pig lungs when challenged with antigen (Dawson, Boot, Cockerill,
DIFFERENTIAL EFFECTS OF OESTRADIOL AND ETHYNYL OESTRADIOL ON LIPID METABOLISM IN THE FEMALE RAT
Authors: VALETTE A. , CARASCO G. , VÉRINE A. , VARÉSI L. , BOYER J. 
Published: December 2008

Service d'Explorations Métaboliques, Hôpital de la Conception, 13385 Marseille Cedex 4, France
(Received 24 July 1978)
It has recently been shown that ethynyl oestradiol markedly decreases lipase activity in the liver (Valette, Verine, Salers & Boyer, 1977). These observations, along with reports of oestrogen receptors in the liver (Chamness, Costlow & McGuire, 1975) suggest that oestrogens exert considerable influence over the hepatic metabolism of lipids. Previous investigations (DeLorimier, Gordon, Lowe & Carbone, 1965; Gallagher, Mueller & Kappas, 1966) have suggested that the extent of the hepatic changes could be correlated with the molecular nature of the hormonal compound and might depend particularly on the 17α-alkyl-substituted group in synthetic oestrogens. The influence of the ethynyl function in the 17α-position of oestradiol-17β on the oestrogen-induced changes observed in hepatic lipases and serum levels of triglycerides has therefore been examined.
Adult female Sprague–Dawley rats (220–240 g) were allowed free access to food and
SIMULTANEOUS RADIOIMMUNOASSAY OF LUTEINIZING HORMONE AND FOLLICLE-STIMULATING HORMONE
Authors: ELLIS M. J. , DONALD R. A. , LIVESEY J. H. 
Published: December 2008

The Medical Unit, The Princess Margaret Hospital, Christchurch 2, New Zealand
(Revised manuscript received 21 August 1978)
The frequent clinical and research requirement for measurement of both plasma luteinizing hormone (LH) and follicle-stimulating hormone (FSH) has prompted the development of a simultaneous radioimmunoassay for these two hormones. The considerable advantages of a simultaneous method include an economy of plasma volume, assay reagents, test-tubes and, more importantly, the time required for radioactive counting and performance of the assay by technical staff. The latter two factors comprise a significant proportion of radioimmunoassay operating costs.
This report describes a simultaneous radioimmunoassay based on the use of 131I-labelled FSH, 125I-labelled LH, anti-FSH serum M93 6873 (a generous gift from Professor W. R. Butt, Birmingham), anti-human chorionic gonadotrophin (HCG) serum for LH measurement (Donald, 1972) and donkey anti-rabbit precipitating serum (Wellcome Reagents, U.K.) for separation of antibody-bound and free hormones. Pituitary gonadotrophin standard (LER 907)
COMPARISON OF THE STIMULATORY EFFECTS OF OVINE, PORCINE AND HUMAN FOLLICLE-STIMULATING HORMONE AND OF OVINE AND HUMAN LUTEINIZING HORMONE ON THE ACCUMULATION OF CYCLIC AMP BY PORCINE GRANULOSA CELLS
Authors: LINDSEY ADA M. , CHANNING CORNELIA P. 
Published: December 2008

The effects of ovine, porcine and human FSH, and ovine and human LH on the accumulation of cyclic AMP by porcine granulosa cells obtained from follicles at various stages of maturation were investigated. During incubation periods of 15 min, 10 μg ovine FSH pretreated with antiserum to LH or 10 μg human FSH resulted in an 11- to 18-fold, five-to ninefold, and less than a twofold increase in intracellular accumulation of cyclic AMP by granulosa cells from small (1–2 mm), medium (3–5 mm) and large (6–12 mm) follicles respectively. Similar patterns of response occurred with addition of porcine FSH. After incubation for 30 and 60 min with ovine, porcine or human FSH, significant accumulation of cyclic AMP in the incubation medium occurred with cells obtained from small and medium-sized follicles. After 60 min of incubation with FSH the accumulation of cyclic AMP in the incubation medium exceeded the intracellular cyclic AMP levels in granulosa cells from small and medium-sized follicles.
During incubation periods of 15 min, 1·0 μg ovine LH resulted in less than a twofold, a fourfold and greater than a tenfold increase in intracellular accumulation of cyclic AMP by granulosa cells from small, medium and large follicles respectively. Addition of human LH brought about a similar response. Incubation periods of 30 and 60 min with 1·0 μg ovine or human LH resulted in significant accumulation of cyclic AMP in the incubation medium by granulosa cells from large follicles; cyclic AMP content in the incubation medium was greater after 60 min compared with 30 min of incubation.
It was concluded that ovine FSH pretreated with an antiserum to LH had similar effects on cyclic AMP levels as did purified human and porcine FSH, and that the stimulatory effects of the less pure ovine FSH were probably not due to an impurity in the FSH preparation. Porcine granulosa cells obtained from small follicles should be suitable as an in-vitro FSH bioassay while granulosa cells obtained from large follicles should be suitable as an in-vitro LH bioassay.
EVIDENCE TO SUGGEST THAT RAT GROWTH HORMONE IS MODIFIED WHEN SECRETED BY THE PITUITARY GLAND
Authors: VODIAN M. A. , NICOLL C. S. 
Published: December 2008

The relationships were examined between the concentrations of GH determined by bioassay (rat tibia test) and radioimmunoassay in homogenates of rat adenohypophysial tissue and in the incubation medium in which the tissue had been maintained. Adenohypophyses from young male rats were incubated in Medium 199 with or without a putative synthetic GH-releasing factor (GRF) to achieve a dynamic state of GH secretion, but the GRF did not consistently stimulate the release of GH as measured by either bioassay or radioimmunoassay. Both assays gave closely similar values for the concentration of GH in homogenates of the adenohypophyses of undisturbed rats. When the two assays were used to measure the concentrations of GH in incubated pituitary tissue, the values showed no correlation, although the concentrations of GH in the incubation medium were again highly correlated. However, the bioassay: radioimmunoassay ratio for the secreted hormone [2·14 ± 0·09 (s.e.m.)] was significantly higher than that for the intrapituitary form from the unincubated gland (0·93 ± 0·06).
By radioimmunoassay, secreted rat GH was found to be less stable than purified rat GH when the two forms were incubated in vitro with slices of various rat tissues. Similarly, the rate of clearance of secreted rat GH from the plasma of hypophysectomized rats, as determined by radioimmunoassay, was much faster than that of the purified GH. The biological activity of purified bovine GH was blocked by aprotinin, an inhibitor of proteolysis, but the drug had no inhibitory effect on the bioactivity of rat GH secreted into the incubation medium.
Overall, these results indicate that secreted rat GH has properties intermediate between those of the intrapituitary form and the form found in the circulation.
CHARACTERIZATION OF THE SPECIFIC BINDING OF PROLACTIN TO BINDING SITES IN THE SEMINAL VESICLE OF THE RAT
Authors: BARKEY R. J. , SHANI J. , AMIT T. , BARZILAI D. 
Published: December 2008

The binding of ovine prolactin to the seminal vesicles of the rat has been characterized and found to be a saturable process, dependent upon time, temperature, protein concentration of the seminal vesicle and divalent ions. Its specificity was similar to that reported for prolactin binding to other organ preparations. Time and temperature studies of the specific binding revealed that equilibrium was reached after 16 h at 5 °C or 4 h at 19 °C. Non-specific binding was also dependent on time and temperature. This parameter has been reported to comprise up to 70% of the total binding to various organ-binding sites, but it fell to below 20% after 48 h at 19 °C, thus demonstrating the high degree of specificity required of target organ receptors.
From degradation studies it was evident that no damage occurred to the free hormone during incubation for up to 70 h at 5 °C or 16 h at 19 °C. However, there seems to be a difference in the susceptibility of bound and free ovine prolactin to damage during incubation: after 40 h at 19 °C the hormone in the supernatant fraction had lost 85% of its binding ability, whereas a high level of specific binding was evident in the pellet. A Scatchard plot of competitive binding studies revealed two classes of binding sites, of which the high-affinity, low-capacity site was similar to that reported previously and consistent with a physiological receptor for prolactin in the seminal vesicle of the rat.
INTERACTION OF OVARIAN TISSUES IN THE CONTROL OF FOLLICULAR STEROIDOGENESIS IN CULTURE
Authors: MOOR R. M. , WALTERS D. E. 
Published: December 2008

The interaction between developing antral follicles and other ovarian tissues in sheep was examined in vitro. Small follicles (2·0–2·9 mm in diameter) were co-cultured with a single ovarian component for 48 h, then separated and cultured singly for a further 72 h during which time changes in follicular steroidogenesis and structure were measured.
Control follicles, cultured together for 48 h before separation, had a mean total daily steroid output during the 72 h test period of 180·4 ± 12·6 (s.e.m.) pmol mg tissue−1 24 h−1; oestrogen (61·7 ± 8·2 pmol mg−1 24 h−1) and testosterone (84·4 ± 9·2 pmol mg−1 24 h−1) accounted for 81% of the steroid secreted by control follicles.
The presence of stromal tissue during co-culture depressed (P < 0·01) the subsequent output of total steroid by 22%, oestrogen by 81% and testosterone by 38%; progesterone output was, however, over twice that of the controls. There were no distinctive structural differences between follicles in the control and stromal groups.
Luteal tissue enhanced (P < 0·01) the output of total steroid by 51%, testosterone by 55% and progesterone by 242%; oestrogen output was similar to that in the controls. Follicles co-cultured with luteal tissue were characterized by extensive hypertrophy of the theca interna.
Developing follicles co-cultured with large non-atretic follicles had a similar total steroid output, a slightly higher oestrogen output and more thecal hypertrophy than the controls. Follicles co-cultured with large atretic follicles differed from controls only with respect to their greater capacity to synthesize progesterone.
MAMMARY GROWTH DURING PREGNANCY IN HYPOPHYSECTOMIZED OR BROMOCRIPTINE-TREATED GOATS
Authors: BUTTLE H. L. , COWIE A. T. , JONES E. A. , TURVEY A. 
Published: December 2008

Mammogenesis in primiparous hypophysectomized goats has been assessed between days 60 and 120 of gestation and compared with that found in untreated goats and goats treated with 5 mg bromocriptine/day. There were fivefold increases in the weight of lobulo-alveolar tissue in the hypophysectomized and bromocriptine-treated goats and a tenfold increase in the untreated goats. Histological examination of the mammary glands at 120 days showed normal structure, and determinations of lactose, lactose synthetase, cytosol enzymes, protein, DNA and RNA indicated qualitatively normal initiation of milk synthetic capabilities in both the hypophysectomized and bromocriptine-treated goats. Bromocriptine treatment lowered the plasma concentration of placental lactogen as well as that of prolactin.
The results indicate that placental lactogen has important mammogenic effects during pregnancy.