bluuebunny/crossref_metadata_2025_split huggingface dataset:
OESTROGEN RECEPTORS IN HUMAN UTERINE TISSUE
Authors: EVANS L. H. , HÄHNEL R. 
Published: December 2008

SUMMARY
The uptake and retention of [3H]oestradiol-17β by human uterine and muscle tissue was studied in vitro by incubation of tissue slices. The binding characteristics of immature rat and adult human tissue were compared. Human endometrium had a greater affinity for tritiated oestradiol than human myometrium. Human uterine tissues bound less [3H]oestradiol-17β than rat uterine horns. The difference in retention between a target and non-target tissue in the human tissue was much smaller than in the rat, although still highly significant. Binding was inhibited by low concentrations of oestradiol-17β, U-11100A and hexoestrol, but was not inhibited by the same concentrations of oestrone, oestriol or oestradiol-17α. Freezing the uterine tissue resulted in a loss of specific binding activity. Binding was shown to vary with different uterine specimens. There was a significant difference in [3H]oestradiol-17β retention between the proliferative and secretory phases of the menstrual cycle. The highest endometrial retention was found in endometrial carcinoma.
INHIBITION BY MANGANESE OF THE ACTION OF ANTIDIURETIC HORMONE ON ADENYL CYCLASE IN TOAD BLADDER
Authors: HYNIE S. , SHARP G. W. G. 
Published: December 2008

SUMMARY
In view of the report that Mn2+ stimulates sodium transport in the toad bladder but inhibits the effect of vasopressin on both water flow and sodium transport, the effects of this ion on adenyl cyclase from mucosal epithelial cells of toad bladder were investigated. Mn2+ was found to inhibit activation of adenyl cyclase by arginine vasopressin in the presence of Mg2+ and had no effect on activation of the enzyme by sodium fluoride. This is in marked contrast to the effects of Mn2+ on hormonal activation of adenyl cyclase from other tissues in which no inhibitory effects are seen and in which Mn2+ can replace Mg2+ in the reaction mixture. It is concluded that stimulation of sodium transport by Mn2+ is unlikely to be explainable by adenyl cyclase activation and that Mn2+ is not useful in the differentiation of the two forms of adenyl cyclase which are thought to be required for mediation of water flow and sodium transport stimulation by vasopressin.
A STUDY ON THE EFFECT OF INSULIN ON DNA, RNA AND PROTEIN SYNTHESIS IN MOUSE MAMMARY GLAND TISSUE IN ORGAN CULTURE
Authors: WANG D. Y. , AMOR VICKY 
Published: December 2008

SUMMARY
The rates of synthesis of DNA, RNA and protein of mouse mammary gland explants in organ culture have been determined. Stimulation with insulin resulted in maximal rates of synthesis of these components, all occurring between 18 and 22 h of culture.
The use of metabolic inhibitors of DNA, RNA or protein synthesis showed that after insulin stimulation, inhibition of any one of these processes was associated with a reduction in the synthesis of the other two components. Also the maximal rate of protein synthesis is governed by the net amount of RNA formed throughout the period of culture.
Evidence is presented that the stimulation of DNA, RNA or protein synthesis by insulin is not due to increased transport of amino acids and that insulin appears to act rapidly on processes which subsequently lead to enhanced synthetic activity.
TRANSFORMATION IN VITRO OF [4-14C]DEHYDROEPIANDROSTERONE TO 7-OXYGENATED DERIVATIVES BY NORMAL EARLY HUMAN PLACENTAL TISSUE
Authors: MIRHOM Y. W. , SZONTÁGH F. E. 
Published: December 2008

SUMMARY
Samples from three early human placentae were incubated with [4-14C]-dehydroepiandrosterone (DHA). It was found that [4-14C]DHA was transformed into 7-oxygenated derivatives in yields decreasing in the order: 7-oxo-DHA > 7β-hydroxy-DHA > 7α-hydroxy-DHA. These products were only slowly transformed into other derivatives.
THE ROLE OF OESTROGENS IN SPONTANEOUS OVULATION: LOCATION OF SITE OF ACTION OF POSITIVE FEEDBACK OF OESTROGEN BY INTRACRANIAL IMPLANTATION OF THE ANTI-OESTROGEN I.C.I. 46474
Authors: BAINBRIDGE J. G. , LABHSETWAR A. P. 
Published: December 2008

SUMMARY
In an attempt to locate the site(s) of action of the positive feedback of oestrogen for ovulation, a potent anti-oestrogen, I.C.I. 46474, was stereotaxically implanted into various parts of the brain or into the anterior pituitary. A dose of 5 μg of the anti-oestrogen when implanted into the cerebral cortex or injected subcutaneously on the morning of the day before pro-oestrus in 4-day cyclic rats was only marginally active in interfering with ovulation. By contrast, when the same amount was implanted into the median eminence region or the anterior pituitary, ovulation failed to occur in 80–100% of the rats (P < 0·05). Implantation of the cocoa butter vehicle alone into these regions interfered with ovulation in less than 35% of animals. Introduction of the anti-oestrogen into the anterior hypothalamic or mammillary region gave equivocal results. The data suggest that both the median eminence and the anterior pituitary contain receptors which can be blocked by the anti-oestrogen with resultant inhibition of ovulation. It is concluded that the positive feedback of oestrogen for ovulation is exerted both at the pituitary and the hypothalamic levels.
REGULATION OF PRODUCTION IN VITRO OF 5α-ANDROSTANE-3α,17β-DIOL IN THE IMMATURE RAT OVARY
Authors: SPRINGER C. , ECKSTEIN B. 
Published: December 2008

SUMMARY
The pattern of steroid synthesis in vitro in ovarian homogenate of immature rats was investigated with [7α-3H]pregnenolone as radioactive precursor. The metabolites, progesterone, androstenedione, testosterone and 5α-androstane-3α,17β-diol were obtained in radiochemically pure form. The steroids were identified by fractionation, partition column and thin-layer chromatography, derivative formation and by crystallization to constant activity. The steroidogenic patterns at the ages of 21 and of 31 days were found to be similar, but different from the pattern reported for adult rat ovaries. At 34 days of age, 1 day before the onset of puberty, the percentage radioactivity converted to progesterone was about ten times higher than that at 31 days. The production in vitro of 5α-androstane-3α,17β-diol by ovarian homogenates of 34-day-old rats was shown to depend on the concentration of pregnenolone in the incubation mixture. These findings are discussed in relation to the mechanism of the onset of puberty in the female mammal.
THE INFLUENCE OF OVARIAN HORMONES ON THE DECIDUAL ALKALINE PHOSPHATASE REACTION IN ADRENALECTOMIZED PSEUDOPREGNANT RATS
Authors: MANNING J. P. 
Published: December 2008

SUMMARY
The influence of oestradiol-17β and/or progesterone on decidual alkaline phosphatase was studied in adrenalectomized (day 1) and ovariectomized (day 1) rats after uterine traumatization on day 4 of pseudopregnancy. Enzyme activity was 10–15 times greater on day 8 of pseudopregnancy in untreated adrenalectomized and intact animals than in non-decidualized uteri. Treatment of ovariectomized and/or adrenalectomized rats with seven daily injections of 5 mg progesterone alone or combined with oestradiol-17β (0·1 μg on days 1–3, and 1·0 μg on days 4–7), did not alter the enzyme reaction. If 1·0 μg of the oestrogen was administered with 5 mg progesterone from days 1–7, no deciduoma response was observed. The results substantiate the hypothesis that progesterone is the only ovarian and adrenal hormone necessary for decidualization of traumatized uteri in pseudopregnant rats.
THE EFFECT OF SURGICAL ISOLATION OF THE HYPOTHALAMUS UPON REPRODUCTIVE FUNCTION IN THE FEMALE GUINEA-PIG
Authors: BUTLER JEAN E. M. , DONOVAN B. T. 
Published: December 2008

SUMMARY
Under stereotaxic guidance, the connexions between the hypothalamus and the rest of the brain were severed surgically in mature female guinea-pigs, and reproductive function was assessed by following the vaginal cycle and by histological study of the ovaries. Animals in which the hypothalamic island incorporated the suprachiasmatic nuclei, or in which the anterior connexions to the hypothalamus were severed by a cut placed just anterior to the suprachiasmatic nuclei, developed persistent vaginal oestrus. Such an anterior cut in the hypothalamus did not influence luteal function in hysterectomized animals. When the anterior border of a hypothalamic island, or an anterior cut through the hypothalamus, was caudal to the suprachiasmatic nuclei, oestrous cycles continued although they were slightly irregular. The ovaries contained corpora lutea. Severance of the posterior connexions to the hypothalamus did not alter the oestrous cycle. The role of the suprachiasmatic area in the generation of persistent vaginal oestrus is discussed.
STEROID CONTENT OF THE EQUINE OVARY DURING THE REPRODUCTIVE CYCLE
Authors: YOUNGLAI E. V. 
Published: December 2008

SUMMARY
Follicular fluid from individual follicles was collected from nine mares in oestrus and the concentration of the following steroids determined by gas—liquid chromatography: progesterone, 17α-hydroxyprogesterone, androstenedione, 19-norandrostenedione, epitestosterone, oestrone and oestradiol. The most vascular follicles, which were probably those destined to ovulate, tended to have the highest steroid concentrations. In these vascular follicles oestradiol was the main steroid found with an average concentration of 151 μg/100 ml.
In two out of three samples of follicular fluid taken from the mares with recent ovulations, oestradiol was present in large quantities. The corpora lutea from these mares contained the following steroids: progesterone (average: 1973 μg/100 g), 17α-hydroxyprogesterone (average: 65 μg/100 g), 20α-dihydroprogesterone (average: 249 μg/100g), pregnenolone (average: 33 μg/100 g). Pregnenolone was not detected in any of the samples of follicular fluid examined.
A pool of eight mid-cycle corpora lutea contained the same four steroids as those in newly formed corpora lutea but, in addition, oestradiol was detected in the order of 4 μg/100 g.
THE ROLE OF PROLACTIN IN THE REGULATION OF TESTICULAR FUNCTION: THE EFFECT OF PROLACTIN AND LUTEINIZING HORMONE ON 3β-HYDROXYSTEROID DEHYDROGENASE ACTIVITY IN THE TESTES OF MICE AND RATS
Authors: HAFIEZ A. A. , PHILPOTT J. E: , BARTKE A. 
Published: December 2008

SUMMARY
Administration of 100 μg prolactin twice daily for 3 days increased 3β-hydroxysteroid dehydrogenase (3β-HSD) activity in the testes of dwarf mice compared with that found in the normal mouse. In hypophysectomized rats, prolactin (200 μg, same regimen) was without effect when given alone, whereas 5 μg luteinizing hormone (LH) alone injected twice daily, increased 3β-HSD activity to above normal. When prolactin and LH were administered in combination, 3β-HSD activity was raised to normal levels only.
EFFECT OF OESTROGEN ON OESTROUS BEHAVIOUR AND ITS VARIATION WITH SEASON IN THE EWE
Authors: FLETCHER I. C. , LINDSAY D. R. 
Published: December 2008

SUMMARY
The effects of dose of oestrogen and season on the expression of oestrous behaviour was studied in 60 spayed and 16 intact ewes.
In progesterone-primed spayed ewes the incidence and duration of oestrous behaviour increased and the interval between injection of oestrogen, and onset of oestrous behaviour decreased as the dose of oestrogen was increased. The linear regression of duration of oestrus on log dose of injected oestrogen provided the most precise measure of the effect of changing dose level of oestrogen on oestrous behaviour.
The sensitivity of spayed ewes to constant levels of oestrogen increased to a maximum near the middle of the breeding season and then declined to a minimum during the non-breeding season. In progesterone-synchronized intact ewes the interval between the end of progesterone treatment and onset of oestrus was at a minimum, and duration of oestrus at a maximum, near the middle of the breeding season. By bioassay it was estimated that endogenous oestrogen production was greater near the middle of the breeding season than at either the beginning or end.
It is concluded that seasonal variation in the expression of oestrous behaviour in intact ewes is controlled by changes in both the production of endogenous oestrogen and the sensitivity of ewes to it.
FEEDBACK EFFECTS OF THYROXINE ON THE HYPOTHALAMUS AND PITUITARY OF GOLDFISH, CARASSIUS AURATUS
Authors: PETER R. E. 
Published: December 2008

SUMMARY
The effect on thyroid activity of a systemically ineffective dose of thyroxine (T4) implanted in the hypothalamus or pituitary of goldfish was tested. Thyroid activity was decreased by T4 implantation in either location, indicating that T4 has a negative feedback effect on the pituitary causing a decrease in thyrotrophin secretion, and a positive feedback effect on the hypothalamus stimulating the secretion of thyrotrophin inhibitory factor (TIF). Fish with a T4 or blank-control implant in the pituitary that had a damaged pituitary stalk, as a result of the operative procedures, were hyperthyroid, suggesting either that TIF is more effective in suppressing thyrotroph activity than T4 and that the effect of T4 was masked by the absence of TIF, or, less likely, that T4 negative feedback in the pituitary is not effective independent of TIF. The results were compared with the information about T4 feedback in mammals.
RENIN LEVELS IN THE KANGAROO, THE WOMBAT AND OTHER MARSUPIAL SPECIES
Authors: SIMPSON PAMELA A. , BLAIR-WEST J. R. 
Published: December 2008

SUMMARY
A renin—angiotensin system was shown to be present in several marsupial species in plasma and homogenates of the renal cortex. Species studied were: Eastern Grey kangaroo (Macropus giganteus), Red kangaroo (Megaleia rufa), common wombat (Vombatus hirsutus), pademelon (Thylogale billardierii), Bennett's wallaby (Wallabia rufogrisea frutica), a quokka (Setonix brachyurus) and a tiger cat (Dasyurus maculatus). Renin-substrate was found in the plasma of the Eastern Grey kangaroo, the Red kangaroo and the wombat. Renin was shown to be present in the plasma of all species by incubation alone or with heterologous marsupial renin-substrate. Plasma renin concentration and renal renin content were estimated by an established method using standard sheep renin-substrate. Plasma renin concentration was high, suggesting that marsupial renins have a high affinity for sheep substrate; renal renin estimates were low relative to eutherian species, suggesting that renal storage may be small. Plasma renin concentration and renal renin levels were proportionately related. Renin levels were consistently lowest in the wombat. Bilateral nephrectomy of an Eastern Grey kangaroo reduced plasma renin concentration to zero and increased renin-substrate concentration eightfold. The angiotensin-like incubation product from Eastern Grey kangaroo renin-substrate did not cross react with antibodies to [5-Ile]-angiotensin I, suggesting that the product has a different sequence of amino acids.
DISULPHATES OF NEUTRAL STEROIDS IN THE AMNIOTIC FLUID FROM ANENCEPHALIC PREGNANCIES
Authors: LUUKKAINEN T. , MICHIE E. A. , VIHKO R. 
Published: December 2008

SUMMARY
Steroid disulphate fractions were obtained by chromatography on Sephadex LH-20 from samples of amniotic fluid from three pregnancies complicated by anencephaly. Several of the steroids with a 3β-hydroxy-5-ene structure found in normal amniotic fluid could not be detected. 5-Androstene-3β,17α-diol, the main steroid disulphate in normal amniotic fluid was present in concentrations of <5% of the values at normal term. The disulphates of neutral steroids found in highest concentrations in the amniotic fluid of anencephalic pregnancies were those of isomeric pregnanediols; 5α-pregnane-3α,20α-diol, 5α-pregnane-3β,20α-diol and 5β-pregnane-3α,20α-diol. The quantities of these metabolites of progesterone in the amniotic fluid of anencephalic pregnancies were similar to those in normal pregnancies. A saturated 18-hydroxylated C19 steroid, most probably 3α,18-dihydroxy-5α-androstan-17-one, was identified by gas—liquid chromatography and gas chromatography—mass spectrometry. Although this compound has been previously identified in human bile and in normal pregnancy urine, this appears to be the first identification of a saturated C19 steroid in amniotic fluid.
STRUCTURAL CHANGES ASSOCIATED WITH INHIBITION OF INVOLUTION OF THE MAMMARY GLAND IN THE ALBINO RAT
Authors: RICHARDS R. C. , BENSON G. K. 
Published: December 2008

SUMMARY
Litters were removed from post-parturient rats on day 4 of lactation and the mothers were then treated with various hormones and pharmacological substances. All treatments (oxytocin, reserpine, prolactin (PR), prolactin+ growth hormone (GH), prolactin + adrenocorticotrophin (ACTH)) resulted in a significant retardation of mammary involution. Both oxytocin and reserpine treatment had little effect on the maintenance of the ultrastructure of the mammary epithelial cells, although after reserpine treatment fat droplets were more frequently observed in the epithelial cells. Treatment with PR, PR + GH and PR + ACTH resulted in a progressive maintenance of the ultrastructure of the epithelial cells, with increased fat present in these cells. However, all treatments failed to alter the distribution of the macrophage-like cells and no alteration in the lysosomes was apparent. The factors involved and the mechanisms by which these treatments might have exerted their effect are discussed.
PARTIAL FRACTIONATION OF OESTRADIOL-BINDING CHROMATIN FROM DIMETHYLBENZANTHRACENE-INDUCED RAT MAMMARY TUMOUR
Authors: POOLEY A. S. , KING R. J. B. 
Published: December 2008

SUMMARY
The distribution of [6,7-3H]oestradiol-17β binding in chromatin from dimethylbenzanthracene-induced rat mammary adenocarcinoma was studied by differential centrifugation of sonicated nuclei. The evidence suggests that more oestradiol-17β is associated with the 'light' chromatin sedimenting at a higher centrifugal force than with the 'heavy' chromatin. Electron microscopy showed that heterochromatin was present in intact tumour nuclei, but it dispersed during isolation of the nuclei, and probably did not account for the fractionation of chromatin that occurred. No heterochromatin was observed in the centrifuged fractions. The template activity appeared to be higher in the fractions that had bound oestradiol. These results are compatible with the view that oestradiol binds to restricted regions of the chromatin and stimulates local increases in transcription.
THE MECHANISM OF OESTRADIOL BINDING IN RAT HYPOTHALAMUS: EFFECT OF ANDROGENIZATION
Authors: VÉRTES MARIETTA , KING R. J. B. 
Published: December 2008

SUMMARY
The uptake of [6,7-3H]oestradiol in vivo and in vitro by cell fractions from regions of rat brain and the anterior pituitary gland has been studied. Cytoplasmic and nuclear receptors were detected in anterior and posterior hypothalamus but not in brain cortex.
After labelling in vivo, tissues took up [6,7-3H]oestradiol in the following order of magnitude: anterior pituitary > anterior hypothalamus > posterior hypothalamus > cortex. With the exception of the cortex, all extracts from mature tissues had a higher uptake/mg protein than did extracts from immature animals. In the in-vitro system, oestradiol-17β competed with [6,7-3H]oestradiol-17β in the hypothalamus whereas progesterone, testosterone and oestradiol-17α did not. In the pituitary, oestradiol-17α and 17β competed for binding sites.
A single injection of testosterone propionate on the second day of life affected [6,7-3H]oestradiol binding in later life. By 28 days of age, the androgenized animals had a lower nuclear and higher cytoplasmic uptake of [6,7-3H]oestradiol in anterior hypothalamus. This effect was not seen in the posterior hypothalamus or cortex. Binding was decreased in all fractions from the pituitary. In mature animals (60 days old), binding fell in both nuclear and cytoplasmic fractions from anterior hypothalamus and pituitary. The nuclei from posterior hypothalamus also took up less [6,7-3H]oestradiol after androgenization. Androgenization affected specific binding in uteri at both 28 and 60 days of age.
EFFECTS OF CORTICOTROPHIN AND DEXAMETHASONE ON THE LEVELS OF CORTICOSTEROIDS, ADRENALINE AND NORADRENALINE IN THE ADRENAL GLANDS OF CATS
Authors: RIVAS CARMEN , BORRELL SARA 
Published: December 2008

SUMMARY
The concentration of adrenaline, noradrenaline and corticosteroids in the adrenal glands of intact cats was studied after administration of corticotrophin (ACTH) or dexamethasone. The animals were treated with ACTH for 3, 7 or 14 consecutive days and killed 3 h (group A) or 24 h (group B) after the last injection. In group A the levels of corticosteroids were significantly increased. Significant decreases were found in group B. A significant decrease in noradrenaline concentration was found in all experiments after administration of both ACTH and dexamethasone. No significant change in the adrenaline level was observed after only 3 days of ACTH or dexamethasone administration, but significant decreases were obtained in both groups after injection of ACTH for 7 to 14 days. These findings suggest that the decrease in adrenal adrenaline may be secondary to the significant and greater decrease in adrenal noradrenaline and that in the intact cat the glucocorticoid levels, although regulating the activity of the adrenal enzyme for methylation of noradrenaline, may not be the only factor involved in the control of adrenaline production by the adrenal gland.
A COMPETITIVE PROTEIN-BINDING ASSAY FOR TESTOSTERONE IN THE PLASMA OF THE BULL AND THE RAM
Authors: KATONGOLE C. B. 
Published: December 2008

SUMMARY
A method is described for the measurement of testosterone in peripheral blood plasma by competitive protein binding, using a 1:80 dilution of human late-pregnancy plasma and Sephadex for separating protein-bound from unbound steroid. The reliability criteria were examined in detail for plasma from bulls and rams. Testosterone was measured with a high degree of accuracy, and with a precision of 4·9–7·9% in the concentration range of 4–24 ng/ml. The specificity of the method was checked by comparing it with a gas-chromatographic technique, and the agreement was good. The testosterone concentrations in the peripheral plasma of bulls and rams were found to range between 2 and 24 ng/ml.
RESPONSE OF NORMAL, HYPOTHYROID AND HYPOTHALAMO-PITUITARY INSUFFICIENT CHILDREN TO SYNTHETIC THYROTROPHIN-RELEASING HORMONE
Authors: MILHAUD G. , RIVAILLE P. , MOUKHTAR M. S. , BINET E. , JOB J. C. 
Published: December 2008

SUMMARY
Thyrotrophin-releasing hormone (TRH) was synthesized by the solid phase technique, administered to 13 children, and the time-course changes in the serum level of thyroid-stimulating hormone (TSH) assessed. In eight normal children, peak levels of TSH occurred 20 min after the injection, and circulating TSH remained significantly raised for 60 min. In three hypothyroid children, the increase in serum TSH was much greater than in normal children, suggesting the existence of large pituitary TSH stores. In two hypopituitary children with TSH deficiency, TSH reserves seemed normal. One of these patients had a craniopharyngioma; after operation, the increase in serum TSH was reduced. These results show that assay of serum TSH after administration of synthetic TRH provides a test which distinguishes pituitary from hypothalamic defects affecting TSH secretion.