bluuebunny/crossref_metadata_2025_split huggingface dataset:
VARIATIONS IN CONCENTRATIONS OF PROLACTIN, LUTEINIZING HORMONE, GROWTH HORMONE AND PROGESTERONE IN THE PLASMA OF BROODY BANTAMS (GALLUS DOMESTICUS)
Authors: SHARP P. J. , SCANES C. G. , WILLIAMS J. B. , HARVEY S. , CHADWICK A. 
Published: December 2008

The concentrations of prolactin, LH, progesterone and GH were measured in the blood of broody bantam hens. The concentration of prolactin was at its highest when the birds began to incubate their eggs and in six out of nine hens it tended to remain raised until the eggs hatched. The increase in the concentration of prolactin was small: in incubating hens it was only 23% higher than in hens caring for their young and 14% higher than in laying hens (P < 0·05 for both comparisons). The concentration of GH tended to be depressed in hens caring for young but otherwise was not related to reproductive activity. The concentrations of LH and progesterone decreased at the onset of incubation and remained depressed while the hens sat on their eggs (P < 0·001 for both comparisons). After the chicks hatched, the level of LH began to increase slowly whereas the level of progesterone remained low. The hens stopped showing broody behaviour between 4 and 10 weeks after the chicks had hatched; this corresponded to the time when the concentration of LH had increased to values found in laying hens.
These observations provide some evidence that prolactin secretion increases at the onset of incubation and support the view that the hormone is not secreted at an increased rate while hens are caring for their young.
EVIDENCE THAT BOTH LONG-ACTING THYROID STIMULATOR AND LONG-ACTING THYROID STIMULATOR-PROTECTOR STIMULATE THE HUMAN THYROID GLAND
Authors: HOLMES S. D. , DIRMIKIS S. M. , MARTIN T. J. , MUNRO D. S. 
Published: December 2008

Thyroid-stimulating immunoglobulins were prepared from two potent sera, one contained long-acting thyroid stimulator (LATS) and the other contained both LATS and LATS-protector (LATS-P). The potencies of the immunoglobulin G (IgG) preparations were estimated in the McKenzie assay.
The accumulation of cyclic AMP in mouse thyroid lobes was stimulated only by LATS–IgG; LATS-P–IgG was inactive. In contrast, both LATS–IgG and LATS-P–IgG were equally effective in slices of human thyroid.
EFFECTS OF CYPROTERONE AND CYPROTERONE ACETATE ON THE ADRENAL GLAND IN THE RAT: STUDIES IN VIVO AND IN VITRO
Authors: PANESAR N. S. , HERRIES D. G. , STITCH S. R. 
Published: December 2008

Male Wistar rats were treated for three weeks with cyproterone (1·7 or 5·1 mg/day) or cyproterone acetate (2 or 6 mg/day). The adrenal weights of animals treated with either dose of cyproterone acetate were significantly less (P < 0·001) than those of untreated animals. In contrast, the adrenal weights of animals treated with cyproterone did not differ from those of the controls. The concentrations of corticosterone in the plasma were significantly less (P < 0·001) in both groups treated with cyproterone acetate compared with those of the controls; only the higher dose of cyproterone reduced the plasma concentration of corticosterone (P < 0·001).
Cyproterone acetate inhibited the rat adrenal 3β-hydroxysteroid dehydrogenase–5-ene,4-ene-isomerase complex in vitro, with both pregnenolone and dehydroepiandrosterone as substrates. Analysis of the reaction rates suggested an uncompetitive mode of inhibition.
These results suggest that in rats the antiandrogens cyproterone and cyproterone acetate may provoke adrenal insufficiency by inhibition of steroid biosynthesis. Furthermore, indirect evidence from the mass and morphology of the adrenal suggests that cyproterone acetate may also suppress production or secretion of ACTH by the pituitary gland.
SEPARATE ROLES OF ANDROGEN AND OESTROGEN IN THE MANIPULATION OF GROWTH AND EFFICIENCY OF FOOD UTILIZATION IN FEMALE RATS
Authors: PERRY B. N. , McCRACKEN A. , FURR B. J. A. , MACFIE H. J. H. 
Published: December 2008

The roles of androgen and oestrogen in the perinatal and postpubertal stages of developmen on the masculinization of female patterns of growth have been investigated in several experi ments in rats.
A stimulatory effect of testosterone on subsequent growth and efficiency of food utilization was only observed when administered perinatally to intact females as the propionate ester. Thus females which were untreated (or androgenized) perinatally and ovariectomized at weaning failed to grow more rapidly or utilize food more efficiently when treated with mixed testosterone esters from 36 to 38 days of age. Also autoimmunity to luteinizing hormone releasing hormone (LH-RH) had little effect on the growth or efficiency of food utilization of male rats, although testicular development was grossly affected.
An inhibitory effect of oestrogen on subsequent growth and efficiency of food utilization was demonstrated by surgical ovariectomy and by autoimmunity to LH-RH. Also perinatal administration of oestradiol benzoate to intact female rats depressed growth below that of untreated intact litter-mate females until about 50 days of age. Then oestradiol benzoate-treated female rats grew to a larger size than untreated intact litter-mates but not to a heavier weight than untreated litter-mate females which like the oestradiol benzoate-treated females, were ovariectomized at 18–21 days of age. Both of these groups of female rats differed markedly in weight gain from females which were perinatally androgenized and ovariectomized at weaning. The effects of androgenization and ovariectomy on weight gain were comparable and additive in female rats fed restrictedly or ad libitum.
Nevertheless, androgenized + ovariectomized female rats fed restrictedly or ad libitum failed to grow as rapidly as male rats. Some additional factor(s) prevents complete masculinization of the female pattern of development. The stimulatory effects of androgenization and ovariectomy on the growth of females appear to be related to endocrine mechanisms controlling the onset of pubertal changes in somatic development.
ELECTROCHEMICAL DEPOSITION OF IRON ONTO RAT OXYTOCINERGIC NEURONES DOES NOT RESULT IN MILK-EJECTION
Authors: DYER R. G. 
Published: December 2008

Exposure of the preoptic-tuberoinfundibular system to iron ions causes ovulation in the pro-oestrous rat. This electrochemical treatment has been used frequently to study the way that the hypothalamus triggers secretion of gonadotrophic hormone and most investigators have assumed that the effect is mediated by the direct excitation of those neurones exposed to the cation. The present paper reports experiments designed to confirm that iron directly excites hypothalamic neurones to the firing frequencies essential for ovulation.
Because of the difficulty of measuring input–output relationships in the diffuse preoptic-tuberoinfundibular system the experiments were performed on the anatomically distinct oxytocinergic neurones of the paraventricular-hypophysial tract in lactating rats. These neurones were stimulated electrically (from 10 to 50 Hz for between 1 and 300 s) and subjected to the electrochemical treatment by depositing iron ions from the tip of the stimulating electrode (up to 250 μA anodal current for between 60 and 180 s). Changes in intramammary pressure were used to indicate oxytocin release and mammary glands were calibrated for sensitivity by intravenous injection of oxytocin.
Electrical stimulation in excess of about 15 Hz invariably caused release of sufficient oxytocin to cause a rise in intramammary pressure. In contrast, no changes in pressure were observed during or after the electrochemical deposition of iron. The results suggest that the response of hypothalamic neurones to electrochemical treatment is not the same as their response to electrical stimulation.
SERUM LEVELS OF THE ACID-ETHANOL SOLUBLE COMPONENT OF NON-SUPPRESSIBLE INSULIN-LIKE ACTIVITY IN UNTREATED AND TREATED STREPTOZOTOCIN-DIABETIC RATS
Authors: FRANKLIN R. C. , RENNIE G. C. , CAMERON D. P. 
Published: December 2008

Streptozotocin-diabetic rats suffered growth failure and had reduced serum levels of the acid–ethanol soluble component of non-suppressible insulin-like activity (NSILA-S) compared with normal rats. Chronic insulin substitution (6 weeks) resulted in a normalization of serum levels of NSILA-S; this was accompanied by a normal increase in weight. Insulin therapy for 3 days resulted in a partial recovery of serum levels of NSILA-S and a slight but significant accompanying gain in weight. Short-term administration of GH also resulted in a partial recovery of the serum level of NSILA-S, in spite of continued uncontrolled diabetes.
These results demonstrate that, in the rat, insulin as well as GH contributes to the regulation of serum levels of NSILA-S.
FOETAL-MATERNAL PRODUCTION AND TRANSFER OF CORTISOL DURING THE LAST DAYS OF GESTATION IN THE GUINEA-PIG
Authors: DALLE M. , DELOST P. 
Published: December 2008

SUMMARY
The metabolism and the rate of transfer of cortisol across the placenta in pregnant guinea-pigs and foetuses were studied by constant intravenous infusions of tritium-labelled cortisol. Estimates of endogenous and radioactive plasma cortisol levels were used to calculate the following parameters at four stages before parturition (days 62, 64, 66 and 67; parturition occurring at day 68): metabolic clearance rate; production rate; adrenal secretory rate; transfer rate from mother to foetus and from foetus to mother; irreversible removal rate; the fraction of cortisol derived from the other in the foetal and maternal vascular compartments; the fraction of secreted and recycled cortisol involved in the transfer. The metabolic clearance rate and the rates of production and secretion of cortisol were higher in the mother than in the foetus between days 62 and 67 of gestation. About 90% of the foetal cortisol was of maternal origin. The fraction of maternal cortisol of foetal origin increased in the last days of gestation.
GLUCOCORTICOID AND MINERALOCORTICOID PATHWAYS IN TWO ADRENOCORTICAL CARCINOMAS: COMPARISON OF THE EFFECTS OF o,p′-DICHLORODIPHENYLDICHLOROETHANE, AMINOGLUTETHIMIDE AND 2-p-AMINOPHENYL-2-PHENYLETHYLAMINE IN VITRO
Authors: TOUITOU YVAN , BOGDAN ANDRÉ , AUZEBY ANDRÉ , DOMMERGUES JEAN-PAUL 
Published: December 2008

SUMMARY
The synthesis of glucocorticoids and mineralocorticoids in vitro was studied in an adrenocortical carcinoma after ablation from an 11·5-year-old boy. This patient had been unsuccessfully treated with high doses of o,p′-dichlorodiphenyldichloroethane (o,p′-DDD) and aminoglutethimide. These in-vitro results were compared with those obtained with another adrenocortical carcinoma removed from a 26-year-old woman who had received no preoperative treatment. The sensitivity of these adrenocortical carcinomas to o,p′-DDD, aminoglutethimide and 2-(p-aminophenyl)-2-phenylethylamine (SKF 12185) was investigated. Synthesis of cortisol (47%) and corticosterone (45%) in control incubations showed that 11β-hydroxylase activity was not affected by the treatment. This explains the raised level of plasma cortisol in the treated child. All three compounds inhibited both 11β-hydroxylase and 18-hydroxylase activities up to 95%, depending on the inhibitor. This study shows (a) an inhibitory effect of o,p′-DDD on the steroidogenesis of an adrenocortical carcinoma in vitro, an effect not previously reported in man or laboratory animals, and (b) the in-vitro efficacy of o,p′-DDD and aminoglutethimide on corticosteroidogenesis by a carcinoma unresponsive to treatment in vivo. This discrepancy between data obtained in vivo and in vitro could possibly be explained by either an insufficient ratio of ingested dose: tumour mass, or a malabsorption of the drugs in this patient.
PHOTOPERIODIC CONTROL OF SEASONAL BREEDING IN THE RAM: PARTICIPATION OF THE CRANIAL SYMPATHETIC NERVOUS SYSTEM
Authors: LINCOLN G. A. 
Published: December 2008

SUMMARY
Four mature Soay rams, cranially sympathectomized by removal of the superior cervical ganglia, were housed alongside four normal rams in controlled lighting conditions of alternating 16 week periods of short days of 8 h light: 16 h darkness (8L: 16D) and long days (16L: 8D). The changes in the concentration of FSH, LH, prolactin and testosterone in the plasma, the size of the testes, the intensity of the sexual flush and the sexual and aggressive behaviour of the animals were recorded.
While the control rams were able to respond to the artificial lighting conditions with synchronized cycles of reproductive activity, the ganglionectomized animals failed to respond. The treated rams had well-developed testes and relatively high levels of gonadotrophins and testosterone in the blood throughout the experiment. It is concluded that the cranial sympathetic nervous system is involved in the photoperiodic control of seasonal breeding in the ram, probably through its role in the innervation of the pineal gland.
ROLE OF THE MESENCHYME IN THE INDUCTION OF THE RAT PROSTATE GLAND BY ANDROGENS IN ORGAN CULTURE
Authors: LASNITZKI ILSE , MIZUNO TAKEO 
Published: December 2008

SUMMARY
Rat prostate glands are induced de novo by androgens in 16·5-day-old male and female urogenital sinuses in vitro as epithelial buds projecting into the surrounding mesenchyme. The role of the mesenchyme in this process has been investigated in various epithelial-mesenchymal recombinations in organ culture.
Isolated epithelium did not form buds but required the presence of the mesenchyme to do so. This requirement seemed to be specific; in the presence of testosterone or dihydrotestosterone only urogenital mesenchyme increased cell division in the urogenital epithelium and stimulated prostatic bud formation. In contrast, heterotypic mesenchyme did not affect epithelial mitosis and failed to induce buds while heterotypic epithelia did not respond to urogenital mesenchyme.
In recombinants of urogenital mesenchyme pretreated with androgen and untreated urogenital epithelium, grown in androgen-free medium, the majority of explants developed prostatic buds while only a few buds were formed from epithelium pretreated with androgen when it was recombined with untreated mesenchyme.
The role of the mesenchyme in the loss of androgen responsiveness of the older female sinuses was examined in heterochronic recombinants. It was found that the old female mesenchyme failed to induce buds in young epithelium while young male or female mesenchymes induced them in the old female epithelium.
The results suggest that the urogenital mesenchyme is essential for the initiation of the foetal rat prostate gland and that it may be a target for androgens and complement or mediate their effect on the epithelium.
EFFECTS OF AROMATIZABLE ANDROGENS ON AGGRESSIVE BEHAVIOUR AMONG RATS (RATTUS NORVEGICUS)
Authors: CHRISTIE MARJORIE H. , BARFIELD R. J. 
Published: December 2008

SUMMARY
Three experiments were used to test the applicability of the aromatization hypothesis of androgen action to aggressive behaviour among Norway rats. In Expt 1, administration of testosterone propionate was highly effective in restoring aggressive behaviour to castrated rats while 17β-hydroxy-5α-androstan-3-one was of intermediate effectiveness. Of the steroids tested in Expt 2, androstenedione and testosterone were highly effective, 17β, 19-dihydroxyandrost-4-en-3-one was of intermediate effectiveness and cholesterol was ineffective. The results of Expt 3 indicated that treatment with testosterone or oestradiol both resulted in increased aggression while treatment with (5α, 17β)-17, 19-bis(acetyloxy)-andostan-3-one diacetate (5α-19-hydroxytestosterone) was without effect. Androgens which were aromatizable and could be 5α reduced, i.e. testosterone, testosterone propionate and androstenedione, were highly effective in restoring aggressive behaviour; however, two other steroids, 5α, 19-hydroxytestosterone which is 5α reduced, and 19-hydroxytestosterone, which can be aromatized, were respectively of low or medium effectiveness on behaviour. However, oestradiol, which did not maintain sexual development of accessory glands, was highly effective in the restoration of aggressive behaviour. Since the behaviourally active steroids in the present experiments were not only those predicted by the aromatization hypothesis, it is proposed that several steroids are capable of activating aggressive behaviour and that the aromatization hypothesis does not adequately explain the hormonal basis of aggressive behaviour among Norway rats.
SERUM PROLACTIN IN THE MALE MOUSE FROM BIRTH TO MATURITY
Authors: BARKLEY M. S. 
Published: December 2008

SUMMARY
The pattern of prolactin secretion was determined throughout the development of the male mouse. Levels of prolactin were at their lowest from birth to 20 days of age. A dramatic increase in serum prolactin occurred during pubertal maturation coincident with rapid growth of the accessory organ system. These events preceded the pubertal rise in the level of serum testosterone that is characteristic of this species.
CHANGES IN CORTICOTROPHIN RELEASING FACTOR OF THE STALK MEDIAN EMINENCE IN RATS WITH VARIOUS CUTS AROUND THE MEDIAL BASAL HYPOTHALAMUS
Authors: MAKARA G. B. , STARK E. , RAPPAY G. , KÁRTESZI M. , PALKOVITS M. 
Published: December 2008

The activity of corticotrophin releasing factor (CRF) in extracts of the stalk median eminence (SME) complex proper (average protein content, 30·6 μg) of male rats was assayed by monolayer cultures of anterior pituitary cells using the release of immunoreactive ACTH. Extracts which were equivalent to 0·025 SME of control rats usually had detectable CRF activity, while there was no detectable activity in extracts of 0·4 SME equiv. taken 8 days after complete surgical isolation of the medial basal hypothalamus (MBH). The activity of CRF in extracts from rats with an anterolateral cut around the MBH was at least ten times less than that in the control rats. One day after placing an anterolateral cut around the MBH the ACTH releasing activity of the SME was not significantly different from that of the control animals but activity decreased significantly 3 days after the operation and was at least ten times less than in the control animals on day 7 after the operation.
It is suggested that most of the CRF activity of the SME is contained in nerve fibres entering the neurohaemal region from outside the MBH and that transection of these fibres produced the fall in CRF content of the SME in rats with partial or total surgical isolation of the MBH.
DETERMINATION OF TAMOXIFEN AND AN HYDROXYLATED METABOLITE IN PLASMA FROM PATIENTS WITH ADVANCED BREAST CANCER USING GAS CHROMATOGRAPHY–MASS SPECTROMETRY
Authors: DANIEL C. P. , GASKELL S. J. , BISHOP H. , NICHOLSON R. I. 
Published: December 2008

An assay has been established for the selective measurement of tamoxifen and its monohydroxy derivative, metabolite B, in human plasma. The assay was used to examine the concentrations of these compounds, relative to oestradiol-17β, in the plasma of patients undergoing tamoxifen therapy for advanced breast cancer. Oral administration of the drug (20 mg twice a day) raised the level of tamoxifen in plasma to approximately 200 ng/ml 20 days after the commencement of treatment. This level was 3000-fold higher than the corresponding concentration of oestradiol which remained within the range for post-menopausal women. Metabolite B was present in plasma at a much lower concentration than tamoxifen although in considerable excess over oestradiol.
The overall results are discussed in relation to the possible mechanism of action of the drug.
MEASUREMENT OF TAMOXIFEN IN SERUM BY THIN-LAYER DENSITOMETRY
Authors: ADAM H. K. , GAY M. A. , MOORE R. H. 
Published: December 2008

A method is described for the determination of tamoxifen in serum. The drug was extracted from the serum and separated from its metabolites by thin-layer chromatography. Irradiation of the thin-layer plate with ultra-violet light after development converted tamoxifen to a fluorescent product which could be estimated in situ by densitometry. The fluorescent product was identified as a substituted phenanthrene by thin-layer chromatography, and gas chromatography–mass spectrometry. The method allowed concentrations as low as 6·8 nmol/l serum to be measured.
After an oral dose of tamoxifen (10 mg) to a female patient the maximum serum concentration (66·2 nmol/l) was achieved in 3 h. When 10 mg tamoxifen were taken twice daily for 21 days by the same patient serum concentrations of about 500 nmol/l were achieved.
ACTIVATION INDUCED BY LUTEINIZING HORMONE OF TYPE II PROTEIN KINASE DEPENDENT ON CYCLIC ADENOSINE MONOPHOSPHATE AND PHOSPHORYLATION OF SOLUBLE PROTEINS IN PORCINE GRANULOSA CELLS
Authors: HALPREN-RUDER D. H. , JUNGMANN R. A. , GEORGE W. J. , JETER J. R. 
Published: December 2008

The present experiments were designed to study whether exogenous LH could elicit acute cyclic AMP-mediated activation of cyclic AMP-dependent protein kinase and phosphorylation of cellular protein in intact porcine granulosa cells.
Incubation of porcine granulosa cells (from 3 to 5 mm diameter follicles) with 2 μg luteinizing hormone/ml (LH) caused a significant rise of cellular cyclic AMP content within 2 min of the addition of LH. The increase was dose-dependent and occurred between doses of 0·2 and 2·0 μg LH/ml. Luteinizing hormone also caused a time- and dose-dependent dissociation of the type II cyclic AMP-dependent protein kinase isozyme in porcine granulosa cells. Luteinizing hormone (0·05–2 μg/ml) significantly dissociated the cyclic AMP-dependent protein kinase between 2 and 30 min after stimulation. The protein kinase dissociation was a specific effect of LH and was not elicited by either adrenocorticotrophic hormone or prolactin. During the period of LH-induced protein kinase activation, several soluble granulosa cell proteins, ranging in molecular weights from about 43 000 to 99 000, became phosphorylated in a time-dependent and hormone-specific manner.
The results suggest that cyclic AMP-mediated activation of granulosa cell type II cyclic AMP-dependent protein kinase may be a prerequisite in the short-term molecular action of LH leading to LH-specific phosphorylation of several soluble granulosa cell proteins of an as yet unidentified function.