bluuebunny/crossref_metadata_2025_split huggingface dataset:
METABOLISM OF [14C]ETHYNYLOESTRADIOL IN THE BABOON
Authors: KULKARNI B. D. 
Published: December 2008

SUMMARY
The amounts of radioactivity in the plasma and in the urine of two normally cycling baboons was studied after intravenous administration of [14C]ethynyloestradiol labelled in the ethynyl side-chain. Within 6 days 76·9–83·3% of the dose was excreted in the urine; 36·4–50·9% appeared on the day of injection, and radioactivity continued to be excreted to the extent of 2·4–2·9% even on day 6. Of the urinary conjugates isolated by neutral resin chromatography, enzymic hydrolysis and solvolysis liberated 57·2–70·5% and 14% of radioactivity respectively. Paper chromatography of the β-glucuronidase-liberated fraction with an intact ethynyl group suggested the presence of at least 11 metabolites. Peaks of radioactivity were found among the more polar compounds which barely moved from the starting line, and among compounds similar in polarity to the administered steroid. The chromatographic results with the metabolites suggest that hydroxylation is an important metabolic pathway for ethynyloestradiol in the baboon.
EFFECT OF A SINGLE INJECTION OF CHLORPROMAZINE INTO INFANT MALE RATS ON SUBSEQUENT GONADOTROPHIN SECRETION
Authors: LADOSKY W. , KESIKOWSKI W. M. , GAZIRI I. F. 
Published: December 2008

SUMMARY
A single injection of 20 μg chlorpromazine/g body weight into male rats 10 days after birth accelerated spermatogenesis when the animals were 45 days old; this was not observed in rats injected on days 1, 5, 8, 12 or 15 of life. When half an ovary was grafted into the eye of rats treated on day 10, they showed a higher incidence of luteinization than ovarian grafts in rats treated at any other age. Compared with animals surgically castrated at the same age, chlorpromazine did not act as by 'pharmacological castration', but induced some alteration in the brain which promoted higher secretion of luteinizing hormone, characteristic of the female pattern of gonadotrophin control, as demonstrated by accelerated spermatogenesis and a higher degree of luteinization. These results suggest that the sexual differentiation of the brain occurs on about the 10th day of postnatal life and can be blocked by chlorpromazine.
ENTEROHEPATIC CIRCULATION OF BILIARY [4-14C]PROGESTERONE METABOLITES IN THE RABBIT
Authors: SENCIALL I. R. , THOMAS G. H. 
Published: December 2008

SUMMARY
Two rabbits were injected intravenously with [4-14C]progesterone and the bile and urine collected for 6 h. The crude bile was administered through an intraduodenal cannula to four rabbits as a single injection, and to three rabbits at a constant rate of infusion for 1·5 h. Bile and urine were collected hourly for up to 7 h. In the single injection experiments 42·3–64·4% of the radioactivity was excreted in the bile and 3·8–13·5% in the urine in 5–6 h. After constant rate infusion 35·4–64·8% and 4·7–9·5% of the radioactivity was excreted in the bile and urine respectively during 6–7 h. The hourly recovery of radioactivity in the neutral fractions of bile and urine decreased with time, whereas radioactivity not accounted for increased. Acidic metabolites represented an insignificant proportion of both biliary and urinary metabolites after enterohepatic recirculation.
THE EFFECT OF ABNORMAL MATERNAL PLASMA CALCIUM LEVELS ON THE OFFSPRING OF RATS
Authors: FAIRNEY ANGELA , WEIR A. A. 
Published: December 2008

SUMMARY
Study of the offspring from parathyroidectomized and hypercalcaemic rats showed that both high and low levels of maternal plasma calcium produced abnormalities in the offspring. Both groups of offspring had hypocalcaemia at birth which reverted to normal by the 7th day of life. All the offspring grew poorly compared with controls. The growth defect in the offspring of the hypocalcaemic rats was reversed if the offspring were reared by normal rats, and in the offspring of the hypercalcaemic rats was accompanied by abnormalities of the fur, including focal alopecia, which reverted to normal when the offspring were weaned on to a normal diet. The calcium concentration in the milk of the hypercalcaemic rats was higher than that in the milk of normal and parathyroidectomized rats.
In the rat the plasma and milk calcium levels in the mother appeared to be important in the aetiology of neonatal hypocalcaemia and growth. It is suggested that the estimation of the plasma calcium in the mother should become a routine procedure in the investigation of cases of neonatal tetany in infants.
THE EFFECTS OF AN INTRA-UTERINE DEVICE ON UTERINE CELL DIVISION AND EPITHELIAL MORPHOLOGY DURING EARLY PREGNANCY IN THE MOUSE
Authors: MARTIN L. , FINN C. A. 
Published: December 2008

SUMMARY
Intra-uterine silk threads in mice prevented the development of a normal progestational epithelium and closure of the uterine lumen on day 5 of pregnancy. It seems likely that either of these effects would prevent implantation.
The intra-uterine device (IUD) produced an abnormal type of luminal epithelium resembling somewhat the hyperplastic type produced by oestrogen treatment, and characterized by increased cytoplasmic basophilia and irregularly placed, swollen nuclei with prominent nucleoli. The IUD also increased the numbers of mitoses in the luminal epithelium. This mitogenic effect was not due simply to inhibition of the suppressive action of progesterone since mitosis was increased on day 3 when progesterone is probably not involved.
All these effects were seen in regions of the uterus remote from the site of the IUD, which suggests that they are caused by factors released into the uterine lumen. In contrast, the effects of the IUD on the glands and stroma appeared to be restricted to the immediate vicinity of the IUD.
It is suggested that IUD's might prevent implantation by stimulating the production of substances which antagonize the actions of progesterone on the uterine luminal epithelium.
AUTOTRANSPLANTATION OF THE PANCREAS IN SHEEP: INSULIN SECRETION FROM THE TRANSPLANT
Authors: BELL J. P. , SALAMONSEN L. A. , HOLLAND G. W. , ESPINER E. A. , BEAVEN D. W. , HART D. S. 
Published: December 2008

SUMMARY
A method of transplanting a part of the pancreas into an exteriorized carotid artery—jugular vein loop in the neck of the sheep is described.
Glucose and butyrate solutions were infused directly into the transplanted pancreas and shown to be powerful direct stimuli of insulin secretion by the pancreatic transplant. Patterns of insulin secretion during prolonged infusions of glucose and butyrate solutions into the pancreatic transplant are described.
One of the sheep described here died 5 months after the transplantation. The other three sheep are all surviving in healthy condition 9, 12 and 18 months respectively, after the transplantation. The transplants of these three sheep continue to secrete insulin.
UPTAKE AND LOSS OF TRITIATED OESTRADIOL BY THE ADRENAL GLAND AND BY OESTROGEN-INDUCED ADRENOCORTICAL CARCINOMA IN THE RAT
Authors: MOBBS BETTY G. 
Published: December 2008

SUMMARY
The loss of injected tritiated oestradiol from the adrenals of non-tumour-bearing rats of different endocrine status and from the adrenals and tumours of animals bearing two lines of transplantable oestrone-induced adrenocortical carcinoma has been studied. There was no evidence that adrenals from non-tumour-bearing rats behaved as 'target organs' for oestrogen as regards retention of the hormone. As compared with skeletal muscle of the same animals, one tumour line and the host adrenals behaved in a similar way to normal adrenals and did not retain oestradiol, whereas the other tumour line and host adrenals lost the hormone at a somewhat slower rate than muscle.
It is suggested that the behaviour of the host adrenals and of the transplanted tumours regarding the injected oestrogen was determined more by the hormonal environment of the tissues including the contribution made by the tumour itself, than by specific oestrogen receptors in adrenal tissue.
IDENTIFICATION OF FOUR TYPES OF STEROID BY THEIR INTERACTION WITH MINERALOCORTICOID RECEPTORS IN THE TOAD BLADDER
Authors: ALBERTI K. G. M. M. , SHARP G. W. G. 
Published: December 2008

SUMMARY
The effects of various steroids on sodium transport across the toad bladder were examined in vitro. Cortisone, alone, had no effect on sodium transport but was an antagonist of aldosterone. Cortisone was shown to bind to the two non-specific binding sites for steroids in the nucleus of the toad bladder epithelial cells when present at a concentration of 10−7m. At higher concentrations it interacted with the mineralocorticoid receptors and displaced aldosterone from these sites. Cortexolone had a weak stimulating effect on sodium transport and also antagonized the effect of aldosterone. Cortexolone, when present in excess, displaced aldosterone from its receptor sites.
Four types of steroid could be differentiated by their interaction with the mineralocorticoid receptor sites and the subsequent biological response: (a) steroids that bind to the receptors and produce the full biological effect on sodium transport; (b) steroids that do not bind and therefore are incapable of producing a response; (c) steroids that bind to the receptor sites, have no effect alone but inhibit the action of aldosterone; (d) steroids that bind to the receptor sites, produce a partial response on sodium transport and subsequently antagonize the action of aldosterone.
Multiple points of attachment are postulated for the steroid—receptor interaction.
THE IMMUNOLOGICAL PROPERTIES OF PORCINE PARATHYROID HORMONE
Authors: WOODHEAD J. S. , O'RIORDAN J. L. H. 
Published: December 2008

SUMMARY
Porcine parathyroid hormone has been isolated and purified. Its size and charge properties are similar to those of bovine and human parathyroid hormones and in a bioassay system the response to porcine hormone is parallel to that of bovine parathyroid hormone. Porcine parathyroid hormone has been labelled with 125I. The immunological properties of the porcine hormone were compared with human and bovine parathyroid hormone in a radioimmunoassay system using antisera against bovine parathyroid hormone. When labelled bovine parathyroid hormone was used as a tracer in the radioimmunoassay, porcine parathyroid hormone could be shown to differ immunologically from the hormones of the other two species. When labelled porcine hormone was used as tracer, it was displaced equally well by hormone from all three species, so that in addition to regions of difference in the molecule there are probably regions of similarity.
EARLY ACTION OF OESTROGEN ON THE INCORPORATION OF [3H]URIDINE IN THE BLASTOCYST AND UTERUS OF RAT DURING DELAYED IMPLANTATION
Authors: MOHLA SURESH , PRASAD M. R. N. 
Published: December 2008

SUMMARY
The incorporation of [3H]uridine into RNA in the blastocyst and uterus has been studied autoradiographically during delayed implantation and after treatment with oestrogen.
Minimal RNA synthesis, as judged by the accumulation of perchloric acid-precipitable isotope originating from [3H]uridine, was seen in the blastocyst during delayed implantation. Treatment with oestrogen enhanced, within 5 min, incorporation of [3H]uridine in a number of cells in all regions of the blastocyst; there was a fourfold increase in the number of grains/cell and the uptake was predominantly located in the nucleus. The number of grains/cell in the blastocyst gradually increased from fourfold at 15 and sixfold at 30 min to a maximal tenfold increase at 60 min after treatment with oestrogen.
Minimal RNA synthesis was seen in the uterus during delayed implantation. Treatment with oestrogen resulted, within 5 min, in a threefold increase in the number of labelled uterine epithelial cells and a sixfold increase in the number of grains/cell in the uterine epithelial nuclei; this level remained the same at 15, 30 and 60 min after hormone treatment. The significance of these results is discussed in relation to early action of oestrogen on the uterus and blastocyst. It is likely that activation of the delayed blastocyst may involve some mechanism which alters cell permeability.
A SOLID PHASE RADIOIMMUNOASSAY FOR OVINE PROLACTIN
Authors: McNEILLY JUDITH R. 
Published: December 2008

SUMMARY
A solid phase-antibody system is described for the radioimmunoassay of ovine prolactin. The sensitivity of the method is equal to 0·5 ng of prolactin/ml. Prolactin was measured in the serum of pregnant and lactating ewes; the levels increased at 5 weeks before parturition and then decreased during the following 3 weeks. A second peak of prolactin was observed at parturition and then the levels gradually decreased during the first 3 weeks post partum.
INDUCTION OF OVULATION IN THE GUINEA-PIG
Authors: REED MAY , HOUNSLOW W. F. 
Published: December 2008

SUMMARY
Ovulation has been induced in the cyclic guinea-pig at a time when the ovaries contain mature follicles, by a single injection of purified luteinizing hormone (LH), follicle-stimulating hormone or guinea-pig gonadotrophins from homogenates of female guinea-pig anterior pituitaries. An injection of any one of the substances given too early only caused follicular luteinization and the ova were retained, even with increased dosage. A single injection of LH in mid-dioestrus caused 'LH effects' on the follicles (destruction of the growing follicles), giving a histological picture similar to that which obtains at the time of ovulation in the untreated animal. Homogenates of anterior pituitaries taken from donor guinea-pigs 1–2 days before ovulation was due (but not at any other time in the cycle) when injected into recipients at middioestrus had similar effects on the follicles. Donor anterior pituitaries taken from guinea-pigs in which ovulation had been inhibited by daily injections of progesterone, caused ovulation in recipients with mature ovarian follicles or 'LH effects' in those in mid-dioestrus. It is suggested that in the guinea-pig there is a basal secretion of gonadotrophins during most of the cycle. A day or two before ovulation occurs and when the ovaries already contain ripe follicles, there is a marked increase in the synthesis of LH which is then released from the anterior pituitary gland and rupture of the follicles occurs.
ADRENAL STEROIDS AND THE ELECTRICAL POTENTIAL OF RAT SMALL INTESTINE IN VIVO
Authors: NOBLE H. M. , MATTY A. J. 
Published: December 2008

SUMMARY
Using a new technique for determining transmucosal electrical potential difference (p.d.) and short-circuit current (Isc.) in the rat small intestine in vivo it would appear that aldosterone had no direct effect on these parameters of intestinal activity. However, adrenalectomy decreased the Isc. while after adrenalectomy aldosterone and cortisol (hydrocortisone) restored the lowered independent and probably also the lowered dependent (hexose) Isc.
ENHANCEMENT OF ON-TIME NIDATIONS IN SUCKLING PREGNANT MICE BY THE PROXIMITY OF STRANGE MALES
Authors: BLOCH SUZANNE 
Published: December 2008

SUMMARY
Female mice, mated at the post-partum oestrus and suckling six young, were exposed to the odour of 'strange' and 'alien' males. The proximity of the males caused nidation, usually delayed during lactation, to occur on time in a great proportion of females. The results are comparable to those obtained by administration of oestrogen to suckling and non-suckling females and it is suggested that the odour of the males brings about a secretion of follicle-stimulating hormone and oestrogen. This secretion might be the cause of the olfactory pregnancy-block in non-suckling females (Bruce effect). In suckling pregnant females pregnancy is blocked in a smaller proportion than in non-suckling ones.
PROGESTERONE SYNTHESIS IN RESPONSE TO LUTEINIZING HORMONE BY RAT OVARIAN TISSUE IN VITRO
Authors: WATSON J. 
Published: December 2008

SUMMARY
A bioassay for luteinizing hormone (LH) activity is described. The method depends on progesterone synthesis by pooled, sliced rat ovarian tissue in vitro, the ovaries being obtained from immature rats pretreated with pregnant mare serum gonadotrophin.
The main advantage of the method is its increased sensitivity compared with the commonly used ovarian ascorbic acid depletion assay, its high degree of precision, and the fact that it allows the use of large numbers of well randomized samples from a small group of animals.
THE BIOASSAY OF LONG-ACTING THYROID STIMULATOR: A COMPARISON OF TWO METHODS
Authors: ENSOR JANICE M. , KENDALL-TAYLOR PAT , MUNRO D. S. , SMITH B. R. 
Published: December 2008

SUMMARY
The McKenzie (1958) assay method and an in-vitro assay method (Brown & Munro, 1967) for the determination of long-acting thyroid stimulator have been compared. Differences in the results were not great: the in-vitro method is simpler to perform and more precise. The sensitivity of the two methods is similar.
The in-vitro method, when used with antiserum to thyroid-stimulating hormone in the medium, provided a satisfactory and simple means for the assay of long-acting thyroid stimulator in the serum of thyrotoxic patients.
EFFECTS OF OVARIECTOMY OR HYPOPHYSECTOMY ON DAY ONE OF PREGNANCY ON DEVELOPMENT AND TRANSPORT OF FERTILIZED RAT EGGS
Authors: WU J. T. , DICKMANN Z. , JOHNSON D. C. 
Published: December 2008

SUMMARY
The development of fertilized eggs and their transport through the oviduct were studied in rats ovariectomized or hypophysectomized on day 1 of pregnancy. When killed on day 5 of pregnancy, 100%, 66% and 27% of the eggs were in the uterus of intact controls, ovariectomized and hypophysectomized rats, respectively. Thus both ovariectomy and hypophysectomy retarded transport of a proportion of the eggs. Ninety-nine per cent, 72% and 78% of the eggs were in the blastocyst stage in intact controls, ovariectomized and hypophysectomized rats. The remainder of the eggs were either morulae or degenerated.
Blastocysts and morulae recovered from the hypophysectomized rats were transferred to the uteri of pseudopregnant recipients: 52–57% developed into normal term foetuses compared to 57% for intact controls.
In hypophysectomized rats killed in the morning of day 6, the number of eggs recovered was greatly reduced as compared with rats killed on day 5. This loss of eggs was prevented by placing a ligature at the cervical end of the uterus in the morning of day 5. It was therefore concluded that the eggs had been expelled from the uterus into the vagina between days 5 and 6.
MELANOPHORE-STIMULATING HORMONE-MELATONIN ANTAGONISM IN RELATION TO COLOUR CHANGE IN XENOPUS LAEVIS
Authors: DIERST-DAVIES KAY , LANDGREBE F. W. , MITCHELL G. M. 
Published: December 2008

SUMMARY
Experiments on colour change of Xenopus laevis were performed to investigate the possibility that melatonin is the physiological antagonist to melanophore-stimulating hormone (MSH). Various amounts of substandard (SS) extract of ox posterior pituitary plus melatonin were injected into the dorsal lymph sac of adult male Xenopus laevis. Normal light-adapted, completely hypophysectomized, and anterior lobectomized animals were used. Dose—response curves were obtained for different SS dosages over a wide range of melatonin concentrations. Melatonin at very low concentrations inhibited the darkening reaction to both injected SS and endogenous MSH. In all cases more melatonin was required to inhibit the effect of SS in hypophysectomized than in normal animals. The results indicate that melatonin may be a physiological MSH antagonist in Xenopus laevis and the pituitary either contains some lightening factor itself ( Hogben's 'W' substance?) or has control over another organ (pineal gland?) where a lightening factor may be present. The unusual linear-logarithmic dose—response curves are discussed.
CAPACITATION AND FERTILIZATION DURING PSEUDOPREGNANCY IN THE RABBIT
Authors: HUNTER R. H. F. 
Published: December 2008

SUMMARY
Capacitation and fertilization during pseudopregnancy in the rabbit were examined on Days 4, 6, 8, 10 and 12 after mating with vasectomized males. At each of these five stages of pseudopregnancy, ovulation was induced in ten animals by a single injection of human chorionic gonadotrophin (HCG); an additional group of oestrous rabbits was similarly injected to serve as controls. Ejaculated spermatozoa were inseminated directly into the Fallopian tubes during laparotomy performed 2 h after the ovulating injection, and 15–22 h later the eggs were examined microscopically for evidence of fertilization.
The mean number and range of induced ovulations decreased between Days 4 and 12 of pseudopregnancy. An overall recovery of 66% of the eggs resulting from these ovulations was achieved, the great majority being located in the Fallopian tubes. Fertilized eggs were obtained from 93% of the 60 does and 84% of the recovered eggs were fertilized. There was neither a decrease in the level of fertilization with advancing stages of pseudopregnancy, nor did the stage of pseudopregnancy influence the rate of development from pronuclear to four-celled eggs. Conspicuous among the small number of abnormal fertilizations were four dispermic pronuclear eggs and two digynic pronuclear eggs.
It is concluded that after injection of HCG, complete capacitation of ejaculated spermatozoa can be achieved in the Fallopian tube between Days 4 and 12 of pseudopregnancy as rapidly as in the tube of oestrous rabbits. Furthermore, a high proportion of the eggs induced to ovulate during pseudopregnancy can be fertilized, though their potential for full embryonic development requires further study.
THE ROLE OF PROLACTIN IN THE SLOUGHING CYCLE OF THE LIZARD, GEKKO GECKO L.
Authors: CHIU K. W. , PHILLIPS J. G. 
Published: December 2008

SUMMARY
Prolactin injected into hypophysectomized geckos restored the length of the sloughing cycle to normal (about 35 days) when given in doses of 0·26 i.u./g body wt on alternate days. When the doses of prolactin were increased to 0·4 i.u. the length of the sloughing cycle was reduced to about 30 days. Prolactin given to thyroidectomized geckos shortened the length of the sloughing cycle to about 28 days when administered in doses of 0·4 i.u./g on alternate days. Prolactin probably acts directly on the epidermis and not through the thyroid gland, since prolactin restored sloughing in thyroidectomized animals. Moreover, prolactin had no effect on the activity of the thyroid gland in the hypophysectomized animals as judged by the percentage uptake of 131I or the histological structure. Prolactin in doses of 0·4 i.u./g on alternate days reduced the length of the resting phase of the sloughing cycle; the renewal phase remained unaltered.
THE ANTIGENICITY OF HUMAN CHORIONIC SOMATO-MAMMOTROPHIN AND HUMAN GROWTH HORMONE IN THE RHESUS MONKEY (MACACA MULATTA)
Authors: BECK J. SWANSON , MELVIN JENNIFER M. O. , MASSON MARY B. R. 
Published: December 2008

SUMMARY
Immunization of nine rhesus monkeys with human chorionic somatomammotrophin (HCSM) consistently produced high-titre monospecific antisera that did not cross-react with the related antigen, human growth hormone (HGH). However, two monkeys immunized with HGH developed lower-titre antisera that cross-reacted with HCSM. By contrast, rabbits and goats did not discriminate to any great extent between HCSM and HGH.
SEASONAL VARIATIONS IN PRODUCTION IN VITRO OF CORTICOSTEROIDS BY THE FROG (RANA RUGULOSA) ADRENAL
Authors: CHAN S. W. C. , PHILLIPS J. G. 
Published: December 2008

SUMMARY
Cyclical changes in the activity of adrenocortical tissue are a wellestablished phenomenon in many amphibian species but up to now they have been studied by observing changes in cytology or enzyme activity, e.g. steroid-3β-ol dehydrogenase. The present study was designed to provide a measure of corticosteroid secretion throughout the seasons using the in-vitro approach. Concomitant histological changes are also recorded and together provide evidence that the adrenal tissue of Rana rugulosa shows maximum activity in the spring spawning season and reaches a minimum in winter.