bluuebunny/crossref_metadata_2025_split huggingface dataset:
ADRENAL BIOGENESIS IN VIVO OF ANDROGENS AND CORTISOL IN THE GUINEA-PIG USING A CONTINUOUS INFUSION TECHNIQUE
Authors: DESHPANDE N. , CARSON PAMELA , HARLEY SHEILA 
Published: December 2008

SUMMARY
An in-situ continuous infusion technique was used to study the biogenesis of androgens and cortisol in the guinea-pig adrenal gland after the infusion of 3H- and 14C-labelled precursors of these compounds. Pregnenolone was converted to 17α-hydroxypregnenolone, progesterone, 17α-hydroxyprogesterone and cortisol. The results of infusion of a combined dose of [3H]17α-hydroxypregnenolone and [14C]progesterone indicated that the major pathway to cortisol is via 17α-hydroxypregnenolone. No conclusive proof could be obtained regarding synthesis of dehydroepiandrosterone or androst-4-ene-3,17-dione. The only androgen detected in the guinea-pig adrenal venous blood was 11β-hydroxyandrost-4-ene-3,17-dione. The major and minor biosynthetic pathways involved in the synthesis of these hormones are discussed.
EFFECT OF TESTOSTERONE ON PROTEIN SYNTHESIS AND CONTRACTILITY OF THE LEVATOR ANI MUSCLE OF THE RAT
Authors: BUREŠOVÁ M. , GUTMANN E. 
Published: December 2008

SUMMARY
The effects of testosterone on the incorporation of leucine and uridine into the proteins and RNA in vitro and on contractile properties of the levator ani muscle were studied.
After long-term preincubation of the muscle with testosterone, incorporation of the labelled precursors into RNA and proteins of the muscle increased by 33 and 78% respectively. No previous treatment in vivo was necessary to show this effect of testosterone.
The increase of incorporation of the labelled precursors into RNA and proteins, tested after preincubation with testosterone, was more pronounced after castration, and was 61 and 134% respectively. The incorporation of labelled precursors into RNA and proteins of the diaphragm muscle of the rat was not affected by preincubation with testosterone in vitro.
Long-term application of testosterone in vitro resulted in a decrease of contraction time and latency period of the levator ani muscle.
FATE OF ANDROSTA-4,16-DIEN-3-ONE AND THE ORIGIN OF 3α-HYDROXY-5α-ANDROST-16-ENE IN MAN
Authors: BROOKSBANK B. W. L. , WILSON D. A. A. , MacSWEENEY D. A. 
Published: December 2008

SUMMARY
The metabolic clearance rate (MCR) of androsta-4,16-dien-3-one (androstadienone) and the cumulative specific activity (CSA) of urinary 3α-hydroxy-5α-androst-16-ene (androstenol) were measured in two healthy men and in one healthy woman after single intravenous injections of 4-[14C]- or 7α-[3H]androstadienone. Approximate plasma production rates, calculated from the MCR and values for the endogenous androstadienone concentration in plasma pools from six male and six female donors (0·984 and 0·366 μg/l respectively), were 975 and 1341 μg/24 h for the two men and 456 μg/24 h for the woman. The 'production rates' of androstadienone calculated from the CSA of urinary androstenol were 5210, 3730 and 1070 μg/24 h respectively. It follows that urinary androstenol is not uniquely derived from circulating androstadienone and it is concluded that both steroids are secretory products. Alternative sources and precursors of urinary androstenol are discussed.
Secretion of radioisotope in the sweat appeared to occur predominantly in the axillae, but was quantitatively no greater than in previous experiments with labelled progesterone and 5-pregnenolone.
KINETIC ASPECTS OF THE DEPRESSION OF 131IODIDE CONCENTRATION BY THYROTROPHIN IN THYROID TISSUE IN VITRO
Authors: MANLEY S. W. , BOURKE J. R. , HAWKER R. W. 
Published: December 2008

SUMMARY
The changes in the kinetics of 131I131I− accumulation accompanying the thyrotrophin (TSH)-induced decrease in the tissue/medium concentration ratio (T*/M*) in propylthiouracil-blocked guinea-pig thyroid slices in vitro have been investigated. 131I− was eluted in serial 2 ml fractions from prelabelled 10 mg thyroid slices incubated for 10 h with TSH. Retrapping of 131I− from the extrafollicular space was abolished by including ClO4− in the elution medium. In the presence of ClO4−, departures from 1st order kinetics were detected by the analysis of regression of successive estimates of instantaneous exit rate, though not by the analysis of regression of logeTt*/T0*. It was predicted that initial exit data would be more representative of exit rates under equilibrium conditions. TSH gave increases in the fractional exit rate (Ktm) of similar order to those required to account for the decrease in T*/M*.
The data support the hypothesis that an increase in 131I− exit rate mediates the decrease in T*/M* induced by TSH.
BLOOD FLOW CHANGES IN THE PITUITARY NEURAL LOBE OF THE RABBIT ASSOCIATED WITH NEUROHYPOPHYSIAL HORMONE-RELEASING STIMULI
Authors: SOORIYAMOORTHY T. , LIVINGSTON A. 
Published: December 2008

SUMMARY
Blood flow rates in the posterior pituitary glands of rabbits were calculated by measuring the clearance of locally deposited 133Xe in saline detected by an externally located probe. These studies indicated that intraarterial injection of CaCl2 and central stimulation of a vagus (both hormone-releasing stimuli) caused a significant rise in blood flow, whilst during haemorrhage, also a release stimulus, the blood flow in the posterior pituitary was maintained. Pretreatment with atropine abolished the increase seen with CaCl2 and vagal stimulation and caused a significant fall in blood flow after haemorrhage. Parasympathomimetic drugs caused an increase in the flow which was also atropine-sensitive; sympathomimetic drugs and sympathetic blocking drugs caused no alteration in blood flow.
These results indicate that there is a local increase in blood flow in the posterior pituitary which is associated with hormone-releasing stimuli and which is cholinergically mediated.
CHANGES IN THE APPEARANCE OF HYPOTHALAMO-NEUROHYPOPHYSIAL NEUROSECRETORY GRANULES ASSOCIATED WITH THEIR MATURATION
Authors: CANNATA M. A. , MORRIS J. F. 
Published: December 2008

SUMMARY
The appearance of neurosecretory granules (NSG) in different parts of the hypothalamo-neurohypophysial system (paraventricular and supraoptic neurosecretory neurones and their processes within the hypothalamus and in the neural lobe) of the rat was studied after fixation at different pH's (5·0, 6·0, 7·0 or 8·0) using a triple-aldehyde mixture followed by osmium tetroxide. Differences between the areas studied were most marked at pH 8·0. At this pH a significantly greater proportion of granules retained an electron-dense core within the perikarya and adjacent processes than within the neural lobe, where only 5% of all granules remained dense-cored. At pH 8·0 comparison of NSG in paraventricular and supraoptic areas showed that a significantly higher proportion of granules remained dense-cored in the paraventricular region. This difference was particularly marked in the neurosecretory processes.
The difference in response to fixation at pH 8·0 between hypothalamus and neural lobe may reflect changes in the nature of the granule resulting from 'maturation'. If so, maturation starts within the perikaryon and proceeds as the granules pass down the axons to the neural lobe, where very few remain immature.
The differences between paraventricular and supraoptic regions might be explained as a result of faster maturation of granules containing vasopressin than those containing oxytocin.
PLASMA CORTICOSTERONE LEVELS DURING PREGNANCY IN THE MOUSE: THE RELATIVE CONTRIBUTIONS OF THE ADRENAL GLANDS AND FOETO-PLACENTAL UNITS
Authors: BARLOW SUSAN M. , MORRISON P. J. , SULLIVAN F. M. 
Published: December 2008

SUMMARY
Plasma corticosterone levels were measured throughout pregnancy and on the first day post partum in the mouse. During the first half of pregnancy plasma corticosterone levels rose from the non-pregnant value of 2·3 μg/100ml to 15·2 μg/100 ml on day 10. During the second half of pregnancy there was a sharp rise, levels reaching a peak of 138·3 μg/100ml on day 16. Following parturition there was a rapid fall to 18·3 μg/100 ml on the morning of the first day post partum. Adrenalectomy on day 15 resulted in an 80% fall in plasma corticosterone levels indicating that most of the steroid was of adrenal origin. The remaining portion of the corticosterone was found to be of foeto-placental origin, and in the chronically adrenalectomized animal this source was capable of maintaining high blood levels of corticosterone (67 μg/100 ml). The foeto-placental unit also provides the main secretory stimulus to the adrenal gland, but the mechanism by which it does this is not understood.
RADIOIMMUNOASSAY OF OESTRONE, OESTRADIOL-17α AND -17β IN BOVINE PLASMA DURING THE OESTROUS CYCLE AND LAST STAGES OF PREGNANCY
Authors: DOBSON HILARY , DEAN P. D. G. 
Published: December 2008

SUMMARY
Specific antibodies were raised against 6-(O-carboxymethyl)oxime—bovine serum albumin derivatives of oestrone, oestradiol-17α and -17β for use in radioimmunoassays to measure each unconjugated oestrogen in peripheral plasma during the bovine oestrous cycle and the last stages of pregnancy. In non-pregnant cows the concentration of oestradiol-17β increased from very low values of 5 pg/ml to 14 pg/ml at oestrus. Oestrone showed little cyclic variation with an average concentration of 4 pg/ml, whereas oestradiol-17α varied inconsistently at much higher levels between 20 and 30 pg/ml.
An increase in the concentration of each oestrogen occurred in the last 14 days of pregnancy with a rapid decrease around parturition. Oestradiol-17β increased from 400 pg/ml on Day — 14 to 1000 pg/ml on Day — 1 with values of 300 pg/ml at parturition. Similar values for oestradiol-17α were 400, 800 and 500 pg/ml with a further decrease to 300 pg/ml, 1 day post partum. Higher concentrations for oestrone were observed: 900 pg/ml on Day — 14, 2800 pg/ml Day — 1, decreasing rapidly to 500 pg/ml on the day of parturition.
EFFECT OF EXERCISE ON THE SECRETION AND METABOLISM OF CORTISOL IN MAN
Authors: FEW J. D. 
Published: December 2008

SUMMARY
Concentration and specific activity of plasma cortisol were measured for 4 h after the intravenous injection of 10 μCi [1,2-3H]cortisol into 14 normal men. Of these subjects four were resting controls; four exercised at a high work load for 1 h; four exercised at a low work load for 1 h and two received infusions of unlabelled cortisol, all beginning 1 h after the administration of [1,2-3H]cortisol.
In the high work load group plasma cortisol had increased by 12·2 ± 6·3 μg/100 ml at the 60th minute of exercise. In this group the half-life of [3H]cortisol was 31·5 ± 5·3 (s.d.) min in contrast to 74·5 ± 8·3 min for the resting controls (P < 0·001).
In the light exercise group plasma cortisol concentration tended to fall, but due to large intersubject differences this was not statistically significant. In this group the half life (t½) of [3H]cortisol was 43·8 ± 3·9 min which was also significantly different from that of the resting controls (P < 0·001).
Specific activity of plasma cortisol fell rapidly (mean t½ = 15 min) during 1 h of heavy exercise, and continued to fall to a nadir 10–30 min after exercise had ceased, finally reaching a value some 60% above the nadir 1·5–2·0 h after exercise had ceased. A similar, although exaggerated, pattern was observed in the two resting subjects into whom 5 and 4 mg respectively, of unlabelled cortisol were infused. In contrast, in the light exercise group cortisol specific activity changed only slowly (mean t½ = 151 min) but continued to fall after exercise.
In the light exercise group, during the latter part of exercise and during the first hour after exercise, the ratio [3H]cortisone: [3H]cortisol in plasma was significantly higher than the corresponding values for the resting group (P < 0·05). Even higher values for this ratio were obtained for some of the heavy exercise subjects but due to wide scatter the group was not statistically significantly different from the resting group.
These results suggest that exercise itself increases the rate of uptake of cortisol by peripheral tissues and that when the work load exceeds a critical level stimulation of the adrenal cortex results in a massive secretion of cortisol which is sufficient to raise the plasma level which in turn promotes further ingress of cortisol into the tissues. After exercise at a high work load a return of cortisol from the tissues to the plasma can be detected.
EFFECTS OF POSTPUBERTAL OESTROGEN INJECTIONS ON MITOTIC ACTIVITY OF VAGINAL AND UTERINE EPITHELIAL CELLS IN MICE TREATED NEONATALLY WITH OESTROGEN
Authors: MORI TAKAO 
Published: December 2008

SUMMARY
Cell cycles of vaginal and uterine epithelial cells were studied using [3H]thymidine autoradiography in adult ovariectomized mice given oestrogen injections neonatally. The mice were in a 'persistent-oestrous' state, showing ovary-independent, continued proliferation and cornification of the vaginal epithelium. The duration of different stages of the cell cycle could not be assessed in such mice, since the percentage of labelled mitoses failed to rise to 100%. In neonatally oestrogenized, adult mice the vaginal epithelium appeared to contain a mixed population of cells. After an oestrogen injection, almost all mitoses of vaginal epithelial cells became labelled, with a generation time of about 17 h. By contrast, the generation time was about 15 h in vaginal epithelial cells of ovariectomized 'normal' mice injected with oestrogen when adult. The uterine epithelium of neonatally oestrogenized, ovariectomized mice also consisted of a mixed population of cells.
A single oestrogen injection produced an increase in both the mitotic rate and cell number in the vaginal and uterine epithelium of ovariectomized 'normal' adults but not in neonatally oestrogenized, ovariectomized adults. These studies show that in mice given oestrogen neonatally, uterine and vaginal epithelial cells were not responsive to oestrogen or at least less sensitive to oestrogen than ovariectomized 'normal' controls.
OESTROGEN, PROGESTERONE AND CORTICOSTEROID CONCENTRATIONS IN PERIPHERAL PLASMA OF SOWS DURING PREGNANCY, PARTURITION, LACTATION AND AFTER WEANING
Authors: ASH R. W. , HEAP R. B. 
Published: December 2008

SUMMARY
Steroid hormone concentrations in plasma have been measured in blood samples taken from conscious sows with ear vein catheters. In late pregnancy, the plasma progesterone concentration ranged from 6 to 12 ng/ml and it decreased in all animals before the onset of parturition. Total unconjugated oestrogens increased to high values of up to about 3 ng/ml in late pregnancy and then declined after the onset of parturition. Oestrone was the predominant unconjugated oestrogen measured. Plasma corticosteroid (mainly cortisol) concentration was about 33 ng/ml and showed no consistent change at the time of parturition.
During lactational anoestrum the plasma concentration of progesterone and total unconjugated oestrogens was very low, while that of corticosteroids was 21 ng/ml. When the piglets were weaned at 26–31 days, sows came into oestrus 4–12 days later, and this was preceded, or accompanied by, an increase in plasma oestrogens. In the luteal phase, plasma progesterone concentrations rose to 20–35 ng/ml. A sow whose piglets were removed at birth, showed signs of oestrus (vulval enlargement and a lordosis response), but a lack of receptivity to the boar associated with no detectable changes in the plasma oestrogen concentration; however, ovulation probably occurred since plasma progesterone values increased in a manner comparable to that found after the formation of normal corpora lutea in other sows. After a second non-receptive cycle, the sow was mated and became pregnant at the third post-weaning oestrus.
At parturition the concentration of progesterone and total unconjugated oestrogens was greater in placental venous plasma than in maternal jugular plasma, which indicates placental synthesis of these hormones. A greater concentration of plasma corticosteroids in foetal blood than in placental venous or maternal jugular plasma suggests foetal synthesis in late pregnancy.
THE PITUITARY-ADRENAL SYSTEM OF THE GENETICALLY OBESE (ob/ob) MOUSE
Authors: EDWARDSON J. A. , HOUGH C. A. M. 
Published: December 2008

SUMMARY
Adult genetically obese (ob/ob) mice which are characterized by adrenal hypertrophy and increased secretion of corticosteroids have considerably increased levels of ACTH in the pituitary gland. At 5 weeks of age there is no difference in the pituitary ACTH content of lean and obese animals and dietary restriction, sufficient to maintain body weight at normal values, reduces the pituitary ACTH content of adult obese mice from 14 times the level found in lean litter-mate controls to almost normal values. Using an in-vitro perifusion system, the release of ACTH from isolated pituitary glands was studied. Pituitaries from lean and obese mice responded similarly to stimulation with a crude extract of hypothalamic tissue containing corticotrophin releasing factor (CRF). The CRF content of the hypothalamus in both groups appears to be similar. In contrast with the high pituitary content, plasma values for ACTH in unstressed obese mice are not increased. The results are discussed in relation to other evidence for a hypothalamic disorder in ob/ob mice.
LIPIDS IN THE MOUSE UTERUS DURING EARLY PREGNANCY
Authors: HALL KATHLEEN 
Published: December 2008

SUMMARY
Lipids in the uterine endometrium of mice during early pregnancy were investigated by histochemical techniques. Three groups of animals were studied: (1) on days 1–8 inclusive of the first pregnancy, (2) on days 1–9 after mating at the post-partum oestrus and suckling seven or eight young from their first pregnancy, (3) on days 1–6 after delivery of the first litter but with no access to males. Day 1 was that on which a seminal plug appeared in the vagina or (group 3) after birth of a litter during the previous night. In post-partum mice, only the areas between the former implantation sites were studied.
Epithelial lipids are sparse during the first 24 h. On day 2 and early day 3 in nulliparous mice, and for a longer period in post-partum mice, the presence of lipid in epithelium and stroma seems mainly a degenerative phenomenon associated with cell breakdown and consequent tissue disruption. During late day 3 and on day 4 the increase in lipid droplets giving staining reactions characteristic for triglycerides may represent the storage in this form of fatty acids no longer needed for phospholipid synthesis or as energy sources, once the intense mitotic proliferation of these cells dies down. Triglycerides also predominated in the necks of the glands, but in the deeper parts, the sparse droplets often gave staining reactions for acidic lipids. In differentiating decidual cells during day 5 and early day 6 in nulliparous mice, histochemical reactions suggest that fatty acids accumulate. Some of these are probably utilized in synthesis of the increasing amounts of phospholipids which were particularly prominent later on day 6 and during day 7, while others appeared to be temporarily stored during that period as triglycerides. The phased deposition and removal of triglyceride proceeds centrifugally through the decidua and is slightly in advance of glycogen deposition and removal in the same cells; its time-course correlated well with that which other workers have described from chemical assay. Histochemical tests appeared to reveal activity of a lipase-esterase (fatty acid ester hydrolase) which strengthened and spread through the decidua in parallel with the disappearance of lipid droplets. In lactating mice, as long as the blastocysts remained in diapause, epithelial lipid resembled that on day 4; in the stromal cells, lipid droplets were plentiful in areas close to the former placental sites but were few or absent elsewhere. Once the delayed implantation had started no abnormalities were detected. Alterations in lipids are discussed in the context of the known changes in the levels of ovarian hormones. Lipids within uterine macrophages are also discussed.
MATERNAL AND FOETAL CORTICOSTERONE LEVELS DURING LATE PREGNANCY IN RATS
Authors: DUPOUY J. P. , COFFIGNY H. , MAGRE S. 
Published: December 2008

SUMMARY
Adrenal and plasma corticosterone levels were determined in rat foetuses and in intact or adrenalectomized mothers during late pregnancy. Foetal adrenal and plasma corticosterone concentrations reached a peak on day 19 of pregnancy, while maternal plasma corticosterone increased on day 18 and remained high until parturition. From day 18, mothers adrenalectomized on day 14 had corticosterone levels similar to those of intact pregnant rats. At every stage of gestation (except day 21) plasma corticosterone levels were higher in the foetuses than in the mothers. The corticosterone concentration in the maternal plasma correlated with the number of live foetuses during the last 3 days of gestation.
These results suggest that corticosterone can cross the placenta from foetus to mother as early as day 18 and that the foetus contributes to the maternal corticosterone pool after day 18.
MAMMARY NUCLEIC ACIDS AND PITUITARY PROLACTIN SECRETION DURING PROLONGED LACTATION IN MICE
Authors: NAGASAWA H. , YANAI R. 
Published: December 2008

SUMMARY
Lactation was prolonged until 61 days by repeated renewal of litters every week after day 12 in primiparous C3H/He strain mice. On days 12, 19, 40 and 61 of lactation, litters were removed for 5 h and after 1 h of resuckling the synthesis of DNA and RNA in the mammary gland was estimated by the incorporation of [3H]thymidine and [14C]uridine into mammary DNA and RNA in vitro respectively. Mammary nucleic acid content and pituitary and plasma levels of prolactin were also assayed. Nulliparous mice were similarly treated on day 19 of pregnancy.
The percentage gain in litter weight per week was highest between days 5 and 12 of lactation, declined until days 26–33 and became steady thereafter. Mammary DNA synthesis was extremely high on day 19 of pregnancy, decreased on day 12 of lactation to less than one-fifteenth of that on day 19 of pregnancy and increased linearly thereafter. Changes in mammary DNA content were not so marked, but DNA content was high on days 12 and 19 of lactation. RNA synthesis was highest on day 19 of pregnancy, abruptly decreased on days 12 and 19 of lactation and increased again with the advance of lactation. Mammary RNA content, RNA:DNA and 14C:3H ratios increased from day 19 of pregnancy to days 12–19 of lactation and decreased on days 40 and 61. While the pituitary levels of prolactin were almost constant during lactation, they were significantly higher than those on day 19 of pregnancy. There were only slight differences in plasma prolactin levels at any stage.
EFFECT OF BILATERAL ADRENALECTOMY AND CORTICOSTEROID THERAPY ON THE SECRETION OF CORTICOTROPHIN-RELEASING FACTOR ACTIVITY FROM THE HYPOTHALAMUS OF THE RAT IN VITRO
Authors: HILLHOUSE E. W. , JONES M. T. 
Published: December 2008

SUMMARY
The rat hypothalamus in vitro preparation was used to investigate the effect of bilateral adrenalectomy, with and without replacement therapy, on the release of corticotrophin-releasing factor (CRF). Corticotrophin-releasing factor was estimated using 48 h basal hypothalamic lesioned assay rats and corticosterone production of excised adrenals was used as the end point.
Bilateral adrenalectomy resulted in depletion of hypothalamic CRF content within the first 2 h after the operation but this effect was prevented by replacement therapy with corticosterone. Thereafter, the hypothalamic CRF content returned to values not significantly different from the intact control level. Bilateral adrenalectomy caused an increase in both basal and acetylcholine-induced release of CRF and it is suggested that corticosteroids exert a negative feedback effect on the hypothalamus.