bluuebunny/crossref_metadata_2025_split huggingface dataset:
EFFECT OF CYSTEINE ON THE BIOLOGICAL AND IMMUNOLOGICAL ACTIVITY OF HUMAN AND BOVINE PARATHYROID HORMONE
Authors: ZANELLI JOAN M. , ATKINS D. , PEACOCK M. 
Published: December 2008

SUMMARY
Human parathyroid hormone extracted from adenomata was assayed biologically by the release of calcium from mouse calvaria in organ culture and immunologically by immunoassay. The human hormone gave a logdose-response curve for calcium release and assayed at 12 units/mg in terms of the M.R.C. Bovine Research Standard A.
Reduction with hot cysteine hydrochloride increased the biological activity of human hormone threefold, and the bovine hormone 4½-fold. An increase in immunological activity could only be shown with bovine hormone, and the purer the preparation the less was the activation of both biological and immunological potencies.
Oxidation with hydrogen peroxide destroyed the biological activity of the bovine hormone but some residual immunological activity of the bovine and human hormones could always be detected. Back reduction with hot cysteine hydrochloride restored the biological and immunological activities of the bovine hormone and the immunological activity of the human hormone but never to the levels of the untreated hormones.
It is suggested that these changes in potency can be induced by changes in the chemistry of the molecule rather than in its metabolism and that the immunological differences between bovine and human hormone represent minor differences in the amino acid sequence of these two hormones.
ACCUMULATION OF NICOTINE IN PANCREATIC ISLETS AND CALCITONIN-PRODUCING CELLS IN MICE AND CHICKS DEMONSTRATED BY MICRO- AND WHOLE-BODY AUTORADIOGRAPHY
Authors: SLANINA PREMYSL , TJÄLVE HANS 
Published: December 2008

SUMMARY
By autoradiographic methods, nicotine was shown to be specifically accumulated in the pancreatic islets in mice. The results also indicated a high accumulation of nicotine in the parafollicular cells of the thyroid in mice and an accumulation was also shown in the ultimobranchial glands in chicks. Like the parafollicular cells of the thyroid in mammals, the ultimobranchial glands of birds are known to produce calcitonin. Metabolic studies with nicotine in vitro and autoradiographic studies with the main nicotine-metabolite cotinine, indicated an accumulation of unchanged nicotine (not metabolites) in the cells.
The results are discussed in view of the fact that biogenic amines have been shown to be operative in these endocrine organs. It is suggested that nicotine can share common transport and/or storage mechanisms with biogenic amines in the cells. An effect of nicotine on hormone storage and/or release may take place via an interference with aminergic mechanisms in the cells.
REFLEX RELEASE OF MILK-EJECTION ACTIVITY BY STIMULATION OF ORGANS IN THE PELVIC REGION IN SHEEP AS STUDIED BY CROSS-CIRCULATION EXPERIMENTS
Authors: PEETERS G. , HOUVENAGHEL A. 
Published: December 2008

SUMMARY
Cross-circulation experiments were performed on sheep by joining the jugular veins of two animals by anastomoses. One of the two animals (B) was a lactating ewe, and the release of hormones from the neurohypophysis in the other animal A (ewe, ram or wether) was investigated by recording the intramammary pressure in B.
The following types of stimulation were carried out on A: (1) distension of vagina or anus; (2) massage of seminal vesicles (SV) or cervix via the rectum; (3) deep massage of the rectal walls, SV or cervix excluded; (4) direct massage of cervix, SV or uterine horns through the abdomen; (5) manipulations in the deep pelvic cavity; (6) distension of the urinary bladder in rams and wethers and pressure upon the filled bladder.
Direct massage of cervix and uterine horns through the abdomen was ineffective. Stimulation of the urinary bladder by distension and pressure induced milk-ejection responses in some animals. Massage of the SV through the abdomen was hardly effective in rams but was effective in two out of seven wethers. The most efficient stimuli, classified according to their ability to induce milk ejection in B, were: distension of the vagina, stimulation of receptors in the retroperitoneal part of the rectum, manipulation in the deep pelvic cavity.
The hypothesis is advanced that reflex release of neurohormones is induced by stimulation of receptors of the afferent pelvic nerves wherever they are situated in the pelvic region. The release of neurohypophysial hormones, provoked by massage of the cervix or SV via the rectum in sheep, is to be attributed primarily to stimulation of receptors in the rectal wall. Reflex hormone release can be elicited just as well in wethers as in rams.
CORTICOSTEROID RELEASE BY ADRENAL TISSUE FROM FOETAL AND NEWBORN LAMBS IN RESPONSE TO CORTICOTROPHIN STIMULATION IN A PERIFUSION SYSTEM IN VITRO
Authors: MADILL DENISE , BASSETT J. M. 
Published: December 2008

SUMMARY
Adrenal glands from 24 foetal lambs (100–145 days gestation) and eight postnatal lambs (birth to 25 days of age) were used to study developmental changes in the responsiveness of the lamb adrenal to stimulation by synthetic adrenocorticotrophin (ACTH). A continuous flow incubation system in vitro (perifusion) was used in these studies. Addition of ACTH to the perifusion medium (0·3 μg Synacthen/ml) significantly increased the rate of corticosteroid release (as measured by a protein-binding assay) by adrenal tissue from foetuses of all ages studied. With tissue from foetuses of 137 days gestation or less, corticosteroid release during ACTH stimulation was < 2 μg/100 mg tissue in the 3 h following addition of ACTH to the perifusion medium. With tissue from foetuses older than this, the rate of corticosteroid release stimulated by ACTH increased as foetal age increased. At 145 days gestation (just before birth) release was 6·8 μg/100 mg tissue and in postnatal lambs less than 1 day old it was 12·3 μg/100 mg tissue during the 3 h following the start of stimulation. This increase in the response of the foetal adrenal to ACTH stimulation paralleled the increases in adrenal weight and plasma corticosteroid concentration which occurred before birth. With tissue from older lambs ACTH-stimulated corticosteroid release was 5·5 μg/100 mg tissue/3 h, a value comparable to that of 5·6 μg/100 mg tissue/3 h obtained with adrenal tissue from adult sheep.
Separation of corticosteroids in the perifusion medium by chromatography on LH 20 Sephadex indicated that adrenals from younger foetuses (< 137 days gestation) released approximately equal amounts of cortisol and corticosterone, whereas adrenals from older foetuses and postnatal lambs released mainly cortisol. Pituitary tissue from all foetuses stimulated corticosteroid release from adrenal tissue of adult sheep, implying that foetal pituitary stores of ACTH do not limit development of foetal adrenal cortex function during the last third of gestation. The results indicate that there is a marked increase during the last week of gestation in the responsiveness of the foetal adrenal to ACTH stimulation and that this increase is related to maturation of corticosteroid biosynthetic pathways during this period.
REGULATION OF GROWTH HORMONE SECRETION IN THE OVINE FOETUS
Authors: WALLACE A. L. C. , STACY B. D. , THORBURN G. D. 
Published: December 2008

SUMMARY
The rate of removal of immunoreactive, intravenously injected 125I-labelled sheep growth hormone (GH) was used to calculate metabolic clearance rates (MCR) in two foetal lambs at 130 days of gestation and in two 6-day-old lambs. The mean MCR calculated for the foetuses was 2·9 ml/min/kg and for the lambs 3·1 ml/min/kg. The concentration of GH in plasma sampled before injection was determined immunologically and the values were used to calculate production rates. A production rate of 924 ng GH/min was calculated for the foetuses and 85 ng GH/min for the lambs. The effect of sectioning the pituitary stalk was studied in two foetuses; after the operation there was a rapid decrease in the circulating levels of GH. Hypophysectomy in two other foetuses also caused an abrupt decrease in plasma GH concentration.
It was concluded from these experiments that the exceptionally high concentrations of GH in the plasma of foetal lambs could not be attributed to impaired removal of the hormone from the circulation. The direct cause of the increased hormone concentrations was a high rate of GH secretion resulting from active stimulation of the foetal pituitary by the hypothalamus.
THE EFFECT OF METABOLITES OF TESTOSTERONE ON THE VIABILITY OF HAMSTER EPIDIDYMAL SPERMATOZOA
Authors: LUBICZ-NAWROCKI C. M. 
Published: December 2008

SUMMARY
The effects of testosterone, dihydrotestosterone, 3α- and 3β-androstanediol on the fertilizing capacity of mature epididymal spermatozoa and on the production of fructose by the seminal vesicles were compared in golden hamsters. When injected subcutaneously into castrated animals, 100 μg testosterone, 75 μg dihydrotestosterone but only 12·5 μg 3α-androstanediol per day were required to maintain the fertilizing capacity at the control level for 12 days; 3β-androstanediol failed to maintain the fertilizing capacity of epididymal spermatozoa for 12 days.
Although testosterone and dihydrotestosterone were equipotent in stimulating production of fructose by the seminal vesicles, 3α- and 3β-androstanediol were much less effective. The discrepancy in the response of the cauda epididymidis and seminal vesicles to 3α-androstanediol suggests that the hormonal requirements for sperm survival in the cauda epididymidis differ from those for the production of fructose in seminal vesicles.
The results suggest that circulating testosterone may be relatively inactive in the cauda epididymidis and that the maintenance of fertilizing capacity of epididymal spermatozoa might be correlated with the reduction of dihydrotestosterone to the more potent androgen 3α-androstanediol by mature spermatozoa.
A SOLID-PHASE RADIOIMMUNOASSAY FOR OVINE FOLLICLE-STIMULATING HORMONE
Authors: CUNNINGHAM N. F. , HEBERT C. NANCY 
Published: December 2008

SUMMARY
A radioimmunoassay using antibody-coated polystyrene tubes is described, which is suitable for the estimation of follicle-stimulating hormone (FSH) levels in sheep blood plasma. Ovine FSH was labelled with 125I by an enzymic method employing lactoperoxidase and H2O2, and was stable for several months at −15 °C. Antisera to ovine FSH were raised in rabbits. Standard curves for unlabelled FSH obtained by this method with different preparations of labelled FSH showed reproducible slopes from day to day.
Ovine luteinizing hormone (LH) and thyroid-stimulating hormone (TSH) showed about 17% cross-reaction in the assay, necessitating the application of a correction to the FSH values for samples of plasma containing more than 15 ng of LH or TSH/ml.
The FSH content of plasma from wethers and anoestrous ewes ranged from 20 to 120 ng/ml.
A RADIOIMMUNOASSAY FOR β-MELANOCYTE-STIMULATING HORMONE IN HUMAN PLASMA
Authors: THODY A. J. , PLUMMER N. A. 
Published: December 2008

SUMMARY
A method is described for the radioimmunoassay of β-melanocyte-stimulating hormone (β-MSH) in human plasma. It was capable of detecting 20–30 pg β-MSH and was unaffected by the presence of α-MSH and human adrenocorticotrophic hormone. However, cross-reactivity did occur with β-glutamyl MSH (porcine).
A simple technique employing porous glass (Florisil) was used to extract β-MSH from plasma. In normal male subjects plasma β-MSH levels ranged from 21 to 133 pg/ml. In patients receiving cortisol therapy for Addison's disease slightly elevated levels were found. Much higher levels were found in patients who had undergone bilateral adrenalectomy as treatment for Cushing's disease.
THE EFFECT OF INTRAHYPOTHALAMIC INFUSIONS OF DOPAMINE AND NORADRENALINE ON OVULATION IN RESERPINE-TREATED FEMALE RATS
Authors: CRAVEN R. P. , McDONALD P. G. 
Published: December 2008

SUMMARY
Cyclic female rats were treated with reserpine (5 mg/kg) on the 2nd day of dioestrus (15.00 h) or on the day of pro-oestrus (11.30 h) to produce a total or partial depletion of brain amines. Ovulation was inhibited in 18 out of 21 rats. Intrahypothalamic infusions of 0·4–80 μg dopamine or noradrenaline on the afternoon of pro-oestrus did not restore ovulation in reserpine-treated rats. In normal pro-oestrous rats, 80 μg dopamine significantly inhibited ovulation, whereas 80 μg noradrenaline had no significant effect. Electrochemical stimulation of the basal hypothalamus or the administration of luteinizing hormone induced ovulation only in those animals treated with reserpine at pro-oestrus. The results indicate that reserpine exerts a marked peripheral effect when given on the 2nd day of dioestrus and has a partial effect on the ovaries when administered at pro-oestrus. The failure of monoamines to induce ovulation suggests that some aminergic synapses involved in gonadotrophin release may lie outside the medial basal hypothalamus. In addition, high levels of dopamine appear to exert an inhibitory action on the release of pituitary gonadotrophins.
THE UPTAKE OF TESTOSTERONE AND ZINC IN VITRO BY THE HUMAN BENIGN HYPERTROPHIC PROSTATE
Authors: REED M. JOAN , STITCH S. R. 
Published: December 2008

SUMMARY
The uptake of 65Zn and [1,2-3H]testosterone by minced tissue of human benign hypertrophic prostates and the subcellular distribution of radioactivity were examined. The nature of steroid and 65Zn binding by the cytosol (105000 g supernatant) fraction was investigated by gel filtration, ion-exchange chromatography and electrophoresis.
It was found that steroid binding after incubation at 4°C was specific. One or two regions of steroid binding were observed after gel filtration of the cytosol using Sephadex G-200, depending upon incubation conditions. Binding of 65Zn was found in the low molecular weight peak after G-200 gel filtration. Equimolar CdCl2 and 65ZnCl2 were incubated with [1,2-3H]testosterone and minced tissue and the cytosol was subjected to gel filtration. Compared with control values, without CdCl2, reduction of 65Zn binding by about 50% occurred, while binding of 3H-labelled steroid was unaffected. Electrophoresis and ion-exchange chromatography showed that 65Zn and 3H-labelled steroid were bound to different proteins. A sample of the zinc-binding protein was prepared by ion-exchange chromatography and the homogeneity was checked by electrophoresis.
ROLE OF THE KIDNEY IN THE METABOLISM OF LUTEINIZING HORMONE
Authors: de KRETSER D. M. , ATKINS R. C. , PAULSEN C. A. 
Published: December 2008

SUMMARY
Autoradiographic localization of 125I-labelled luteinizing hormone (LH) in the renal proximal convoluted tubule of rats initiated a study of the role of the kidney in the metabolism of LH. Incubation of 131I-labelled LH with rat renal homogenates for 90 min failed to destroy its immunological reactivity.
The plasma half-life of 131I-labelled LH injected i.v. was investigated in normal ewes and rams. Preliminary studies indicated that the use of a preparation containing a high proportion of 'damaged' iodinated hormone could erroneously prolong the plasma half-life. Before use, 131I-labelled LH was purified by gel filtration and column chromatography using DEAE-cellulose. The mean plasma half-life of 131I-labelled LH in normal ewes was 26·7 min and was not significantly altered after oophorectomy (31·1 min). After bilateral oophorectomy and nephrectomy, marked prolongation of the plasma half-life was observed (mean 70·7 min). In normal rams, mean plasma half-life of 131I-labelled LH was 32·0 min, after orchidectomy 44·0 min and after orchidectomy and nephrectomy 82·0 min. The plasma half-life of 131I-labelled LH in a nephrectomized ewe maintained on haemodialysis was also prolonged (67·5 min), the determination being performed 24 h after the last haemodialysis. Although the kidney does not degrade LH, the plasma half-life was significantly increased after nephrectomy. This suggests that the localization of 125I-labelled LH in the proximal convoluted tubule may represent a secretory mechanism allowing renal excretion of LH.
THE METABOLIC CLEARANCE RATE, PRODUCTION RATE AND CONVERSION RATIOS OF OESTRONE IN THE SHEEP
Authors: CHALLIS J. R. G. , HARRISON F. A. , HEAP R. B. 
Published: December 2008

SUMMARY
The metabolic clearance rate of oestrone from whole blood and its conversion to oestradiol-17β and oestradiol-17α were measured in pregnant and non-pregnant sheep using tracer kinetic techniques. The clearance rate of oestrone for all animals (3·435 ± 0·212 (s.e.m.) 1/min) was significantly greater than that of oestradiol-17β (2·449 ± 0·155 1/min). The mean conversion ratio of oestrone to oestradiol-17β was 23·8±1·6%, and that of oestrone to oestradiol-17α was 17·7 ± 2·5%. The transfer constant of oestrone to oestradiol-17β was estimated to be 17·5 ± 1·6% compared with that of oestradiol-17β to oestrone which was 23·2 ± 2·5%. The production of oestrone increased from values of 0·141 and 0·240 μg/min up to 2 days before parturition, to between 0·660 and 1·881 μg/min during the last 24 h of pregnancy; these values were appreciably greater than those of oestradiol-17β.
During the continuous infusion of [3H]oestrone or [3H]oestradiol-17β and when a steady state had been reached, the uptake by erythrocytes of [3H]oestrone was 22·3%, that of [3H]oestradiol-17β, 6·6%, and that of [3H]oestradiol-17α, 22·0%. In three experiments on one sheep, the uptake of [3H]oestrone across the head was 11–16%.
STEROID METABOLISM BY ADULT RAT ADRENOCORTICAL CELLS IN MONOLAYER CULTURE
Authors: O'HARE M. J. , NEVILLE A. MUNRO 
Published: December 2008

SUMMARY
The patterns of exogenous steroid metabolism by rat adrenocortical zona fasciculata and zona reticularis cells cultured together as a monolayer have been examined. In the continued presence of corticotrophin (ACTH), the cultured cells synthesized corticosterone, 18-hydroxydeoxycorticosterone and deoxycorticosterone from [3H]pregnenolone. In the prolonged absence of ACTH, however, [3H]pregnenolone was metabolized mainly to progesterone, 20α-dihydroprogesterone, 20α-hydroxy-5α-pregnan-3-one and 5α-pregnane-3β,20α-diol with small amounts of 5α-pregnane-3,20-dione, 11β-hydroxyprogesterone and 11β-hydroxy-20α-dihydroprogesterone, while virtually no corticosterone, 18-hydroxydeoxycorticosterone or deoxycorticosterone were produced. While 5-ene-3β-hydroxysteroid dehydrogenase-isomerase activity persisted at a substantial level in unstimulated cells and the 11β- and 18-hydroxylases were reduced but still present, 21-hydroxylase activity was almost completely lost when ACTH was omitted from the culture medium. These changes in enzyme activities were completely reversed by the addition of ACTH, cyclic AMP or dibutyryl cyclic AMP to unstimulated cultures for 4–5 days, during which time no proliferation of adrenal cells was observed.
METABOLISM OF [4-14C]17α-HYDROXYPROGESTERONE TO UNCONJUGATED METABOLITES IN THE HUMAN FOETO-PLACENTAL UNIT AT MID-PREGNANCY
Authors: LING W. , COUTTS J. R. T. , MACNAUGHTON M. C. , SOLOMON S. 
Published: December 2008

SUMMARY
Labelled 17α-hydroxyprogesterone was injected into the umbilical vein of each of two male previable human foetuses at the time of laparotomy. The umbilical circulation remained intact for 3 min after which time the tissues of the foetuses, placentae and cords were removed, extracted and the labelled unconjugated metabolites formed were identified. The mid-pregnancy human foetus has a high capacity for metabolizing 17α-hydroxyprogesterone, forming corticosteroids, C-19 steroids and a variety of reduced and hydroxylated metabolites. Androstenedione and testosterone were isolated from both the foetal adrenals and testes but the older of the two foetuses studied contributed in major part to this synthesis. All the foetal tissues examined showed a remarkable capacity to metabolize 17α-hydroxyprogesterone.
FORMATION OF CONJUGATED METABOLITES AFTER INJECTION OF [4-14C]17α-HYDROXYPROGESTERONE INTO THE UMBILICAL VEIN OF THE HUMAN FOETUS AT MID-PREGNANCY
Authors: LING W. , COUTTS J. R. T. , MACNAUGHTON M. C. , SOLOMON S. 
Published: December 2008

SUMMARY
After injection of [4-14C]17α-hydroxyprogesterone into the umbilical vein of two male human foetuses at mid-pregnancy a number of steroid conjugates were isolated from the foetal adrenals, liver, intestines and residual tissues, confirming the capacity of the human foetus to conjugate an extensive range of steroid substrates. The conjugated steroids isolated were 17α-hydroxypregnanolone sulphate (liver, intestine), 3β,17α-dihydroxy-5α-pregnan-20-one sulphate (residue), pregnanetriol sulphate (liver, residue), cortisol sulphate (adrenal), pregnanetriol glucosiduronate (liver, residue) and 17α-hydroxypregnanolone glucosiduronate (liver).
MECHANISM OF OESTRADIOL ACTION ON THE RAT UTERUS: INDEPENDENCE OF CYCLIC AMP, PROSTAGLANDIN E2 AND β-ADRENERGIC MEDIATION
Authors: ZOR U. , KOCH Y. , LAMPRECHT S. A. , AUSHER J. , LINDNER H. R. 
Published: December 2008

SUMMARY
The hypothesis that cyclic AMP plays an essential role in mediating the biological action of oestradiol on the uterus, was tested by determining the tissue concentration of the cyclic nucleotide after incubation of uteri of immature rats with oestradiol or after injection of this steroid into immature or ovariectomized rats. The effect of known stimulants of uterine adenyl cyclase, namely β-adrenergic drugs and prostaglandin E2 (PGE2), on the level of cyclic AMP in the uterus was also examined both in vitro and in vivo.
In either system, oestradiol failed to enhance the concentration of cyclic AMP in the uterine tissue, whereas adrenaline or the almost purely β-adrenergic agonist isoprenaline (isoproterenol) caused cyclic AMP accumulation that was susceptible to inhibition by the β-adrenergic blocking agent propranolol. Prostaglandin E2, and to a much lesser degree prostaglandin F2α, increased cyclic AMP concentration in the uterus, but the effect of PGE2 was not inhibited by propranolol. It may be concluded that oestradiol does not cause appreciable stimulation of PGE2 synthesis or activation of β-adrenergic receptors in the rat uterus since, otherwise, increased cyclic AMP production should have been observed after the treatment with oestradiol.
Isoprenaline mimicked the stimulatory action of oestradiol on uterine ornithine decarboxylase. However, this action of isoprenaline was abolished by propranolol, whereas that of oestradiol was only slightly, though significantly, inhibited.
The present findings do not support the view that the action of oestradiol on the uterus is mediated by cyclic AMP, and also suggest that β-adrenergic receptors and PGE2 can have only a minor role, if any, in the mechanism of action of this hormone.
EFFECT OF HYPOPHYSECTOMY ON THE GROWTH HORMONE RESPONSE TO INSULIN-INDUCED HYPOGLYCAEMIA
Authors: ROBERTS M. MAUREEN , FORREST A. P. M. , RICHARDS S. , STEWART H. J. , BOYNS A. R. 
Published: December 2008

SUMMARY
Plasma growth hormone (GH) levels were measured in 55 patients with advanced breast cancer, before and 3 months after pituitary ablation either by yttrium-90 implantation or by transethmoidal hypophysectomy. It was found that four of the 46 patients tested before ablation had an 'absent' GH response to insulin-induced hypoglycaemia. A comparison of the GH response to insulin-induced hypoglycaemia after yttrium implantation and transethmoidal hypophysectomy revealed no difference between the two procedures in the degree of pituitary ablation achieved. A partial GH deficiency occurred in 30% of patients after yttrium implantation but in only 4% after transethmoidal hypophysectomy.