bluuebunny/crossref_metadata_2025_split huggingface dataset:
TISSUE DISTRIBUTION OF CALCITONIN IN THE RAT: COMPARISON WITH PARATHYROID HORMONE
Authors: de LUISE M. , MARTIN T. J. , MELICK R. A. 
Published: December 2008

SUMMARY
When [125I]calcitonin was injected intravenously into rats the major site of accumulation of radioactivity was the liver, whereas [125I]parathyroid hormone was localized chiefly in the kidney.
The distribution of [125I]bovine serum albumin and of Na [125I] was studied for comparison. Although most of the radioactivity of [125I]calcitonin was found in the soluble fractions of liver and kidney, significant binding to liver microsomes occurred. This fraction also bound an appreciable amount of the radioactivity of [125I]parathyroid hormone. The uptake of [125I]calcitonin by liver could be inhibited by the simultaneous injection of unlabelled calcitonin, but not by that of parathyroid hormone, insulin or adrenocorticotrophic hormone.
These results indicate a role for the liver and kidney in the early clearance of calcitonin and parathyroid hormone respectively. It is likely that the liver is the major site of the metabolism of calcitonin in vivo.
THE DEVELOPMENT OF A RADIOIMMUNOASSAY FOR OXYTOCIN: THE EXTRACTION OF OXYTOCIN FROM PLASMA, AND ITS MEASUREMENT DURING PARTURITION IN HUMAN AND GOAT BLOOD
Authors: CHARD T. , BOYD N. R. H. , FORSLING M. L. , McNEILLY A. S. , LANDON J. 
Published: December 2008

SUMMARY
A method is described for the extraction and concentration of oxytocin from plasma which is simpler and more rapid than other available procedures. It has proved satisfactory for both radioimmunoassay and bioassay of circulating oxytocin. The recovery of added oxytocin was 60 ± 5·5% and showed no significant variation between plasma from pregnant and non-pregnant women, or plasma from other species. The sensitivity of the assay is related to the volume of plasma extracted. With a 10 ml plasma sample and the radioimmunoassay method described previously, the maximum sensitivity under optimal conditions is 0·75 μu. (1·5pg)/ml. In the second stage of human labour, oxytocin is not detectable in maternal plasma at this level of sensitivity. Of 36 cord venous plasma samples studied, 15 showed positive results in the range 1·5–20 μu. (3–40 pg)/ml; of 16 simultaneous cord arterial and venous plasmas, 12 showed positive results; the arterial samples showed a range of 8–145 μu. (7–290 pg)/ml with an average of 45 μu./ml; the venous samples showed a range of 0–100 μu. (0–200 pg)/ml with an average of 24 μu./ml. Plasma oxytocin levels during the second stage of labour in the goat averaged 120 μu. (240 pg)/ml by radioimmunoassay and 100 μu. (200 pg)/ml by bioassay. The half-life of infused oxytocin in the non-pregnant human subject as determined by radioimmunoassay was 5 min.
MAINTENANCE OF PREGNANCY RELATIVE TO THE PRESENCE OF FEW EMBRYOS IN THE RABBIT
Authors: ADAMS C. E. 
Published: December 2008

SUMMARY
Either one or two 60-h morulae were transferred to one uterine horn of Polish, Dutch or Strain A rabbits in which the mean number of ovulations was 4·3, 6·4 and 10·8. The pregnancy rate, as determined by palpation on day 10, varied from 45–65% (mean 53%) in recipients of one egg to 69–71% with two eggs. Only 20% of the does carrying one foetus maintained pregnancy to term compared with 87% of those with two implants. If pregnancy failed this usually occurred between days 15 and 20. In a further experiment, in which additional eggs were transferred to the contralateral horn, it was shown that all single conceptuses were inherently capable of surviving to term.
It is concluded that irrespective of breed and ovulation rate, two conceptuses are normally required to prevent regression of corpora lutea on about day 17. Treatment with follicle-stimulating hormone in mid-pregnancy or removal of the barren uterine horn on day 13 failed to maintain pregnancies involving only one conceptus.
THE EFFECT OF AUTONOMIC BLOCKING AGENTS ON VASOPRESSIN RELEASE IN VIVO INDUCED BY OSMORECEPTOR STIMULATION
Authors: BRIDGES T. E. , THORN N. A. 
Published: December 2008

SUMMARY
Intracarotid injection of 0·25 ml of a hyperosmotic (1 m) sodium chloride solution into hydrated rats was an effective stimulus for vasopressin release. The effects of autonomic blocking drugs on this stimulus and on the release of vasopressin by intracarotid injections of acetylcholine were studied.
Anti-adrenergic compounds (reserpine and phenoxybenzamine), ganglion-blocking agents (pempidine and pentolinium) and atropine were shown to be effective in preventing the vasopressin release caused by hyperosmotic stimulation.
Acetylcholine-induced release of vasopressin was inhibited by pempidine but not reserpine.
Based on these findings the nervous pathway(s) involved in the release of vasopressin induced by hyperosmolarity of the plasma is discussed.
EFFECTS OF ANDROGENS AND PROLACTIN ON THE RATE OF PRODUCTION AND COMPOSITION OF SEBUM IN HYPOPHYS-ECTOMIZED FEMALE RATS
Authors: NIKKARI T. , VALAVAARA M. 
Published: December 2008

SUMMARY
The effect of five androgens on the activity of the sebaceous glands of female rats hypophysectomized at 3–4 weeks of age was studied by determining the rate of production and palmitate: stearate ratio of the skin surface lipids. Both of these values reflected the stimulation of the sebaceous glands by androgens, but the palmitate: stearate ratio appeared to be a more sensitive index of low androgenic activity than the production rate. The response of the sebaceous glands to the androgens tested increased in the order (the relative potencies were calculated from the palmitate: stearate ratios): androstenedione, 17; dehydroepiandrosterone, 33; androstanolone, 48; androstanediol, 91; and testosterone propionate, 100. Prolactin did not enhance the stimulation of the sebaceous glands induced by testosterone propionate.
GENETIC VARIATION IN ADRENAL STRUCTURE: QUANTITATIVE MEASUREMENTS ON THE CORTEX AND MEDULLA IN HYBRID MICE
Authors: SHIRE J. G. M. 
Published: December 2008

SUMMARY
The volumes of the adrenal cortex and medulla were measured for young adult male mice from the A/Cam and CBA/FaCam strains and from five hybrid generations produced by crossing these inbred strains. The hybrid stocks were the reciprocal F1's, the F2 and the backcrosses to both parental strains. Two independent sets of measurements were made. The second set confirmed and extended the results of the first. Both the adrenal cortex and the adrenal medulla were significantly larger in the CBA mice than they were in the A mice. It seems likely that the observed difference between the strains in cortical volume was determined by genetic variation either at a single locus or, at most, at two loci. The difference in medullary volume was determined by variation at at least two gene loci. In all cases the alleles found in the CBA mice showed dominance. The problems of deciding whether four separate loci were involved or whether all the differences were due to pleiotropic effects of fewer genes is discussed. In the first experiment measurements of the volume and number of cells in the zona fasciculata were made in addition to those of medullary and cortical volume. These measurements confirmed the existence of genetic variation in these characters which had been suggested by earlier findings of significant strain differences in them. The results of the second experiment also showed that the significant strain difference between A and CBA mice in testis weight was brought about by genes other than those causing the adrenal differences.
The relation between the differences in adrenal structure described in this paper and those known to exist between these two strains in other aspects of the adrenal glands and in their target organs are discussed, as is the relation between findings on inbred strains and those to be expected in natural populations.
THE EFFECT OF EXOGENOUS PROGESTAGEN ON THE LEVELS OF FREE OESTROGEN IN THE OVARIAN VEIN PLASMA OF THE EWE
Authors: SMITH J. F. , ROBINSON T. J. 
Published: December 2008

SUMMARY
The levels of free oestrogen (oestrone and oestradiol-17β) in plasma in the ovarian vein were determined in three groups, each of 27 ewes, at nine intervals at about the time of oestrus. One group had a normal oestrus while the other two had been treated for 16 days with intravaginal sponges containing either 10 or 30 mg of a synthetic progestagen (Cronolone, Searle).
In untreated ewes, the mean level (corrected) of oestradiol-17β in plasma from the active ovary rose from 25·3 ng/100 ml at −48 h to a peak of 91·6 ng/100 ml at 0 h (onset of oestrus) and then fell. There was evidence of biphasic production. The mean level of oestrone was relatively high (13·0 ng/100 ml) at −48 h; it fell to 2·0 ng/100 ml between −36 and −24 h and then rose again to 9·4 ng/100 ml at + 12 h. There was no significant change, with time, in the plasma levels of either oestrogen from the non-active ovary. The total amounts of oestradiol-17β and of oestrone produced from both ovaries at an oestrous period were estimated to average 9·7 and 2·4 μg.
In treated ewes, a similar pattern of production of oestradiol-17β was shown by the ewes treated with 30 mg Cronolone. That of ewes treated with 10 mg differed (P < 0·01). Peak level was reached at an earlier stage, relative to the onset of oestrus, and it declined more rapidly, the total amount of oestrogen produced (oestrone + oestradiol-17β) was less (10 mg Cronolone, 8·6 μg; 30 mg Cronolone, 12·1 μg; normal oestrus, 12·1 μg), and there was no biphasic production.
EFFECT OF ADRENOCORTICOTROPHIC HORMONE AND ANDROST-5-EN-17-ON-3β-YL SULPHATE ADMINISTRATION TO THE MOTHER ON URINARY OESTROGEN EXCRETION IN LATE HUMAN PREGNANCY
Authors: JEFFERY J. , SWAPP G. H. , WILSON G. R. , FOTHERBY K. 
Published: December 2008

SUMMARY
Infusion into the mother of adrenocorticotrophin during late normal pregnancy was accompanied by rises or falls in the urinary excretion of oestrone, oestradiol and oestriol. A similar variable pattern was found when the subjects infused were receiving regular pharmacological doses of glucocorticosteroid (i.e. when maternal adrenal function was reduced) or were carrying anencephalic foetuses (i.e. when foetal adrenal function was reduced). Similar infusion of a substantial quantity of androst-5-en-17-on-3β-yl sulphate (DHAS) was accompanied by rises in oestrogen excretion by normal subjects. The rises were large compared with basal levels, but small (a few per cent) compared with the amount of DHAS infused. The changes in a pregnancy with anencephaly were within the range of the normal subjects. It is concluded that maternal DHAS plays little part in placental oestrogen synthesis, and that some control of oestrogen synthesis from DHAS occurs by the placenta itself.
THE EFFECT OF BETAMETHASONE ON GLUCOSE UTILIZATION AND OXIDATION BY SHEEP
Authors: REILLY P. E. B. , FORD E. J. H. 
Published: December 2008

SUMMARY
Continuous infusions of tracer amounts of [U-14C]glucose were used to measure the effect of a single intramuscular injection of 0·5 mg betamethasone/kg on the rates of glucose entry in six sheep eating 900 g/day chopped hay containing 49 g protein. In four of the sheep the rates of oxidation of glucose to CO2 were also measured. Hyperglycaemia occurred with a maximum plasma glucose concentration occurring 24 h after administration of the steroid. The mean glucose entry rates, expressed as mg/min/kg ± s.e.m., rose from 1·27 ± 0·11 (6) to 1·75 ± 0·16 (6). The difference between these means is significant (P < 0·001). The mean proportion of CO2 derived from glucose after administration of betamethasone (11·64 ± 1·4% (4)) was not significantly different (P > 0·5) from that derived before its administration (12·47 ± 0·34% (4)). The amounts of glucose available for synthetic purposes increased because the total production rates increased. The mean extra amount available was 11·3 ± 2·1 (4) mg C/min. These results are discussed in the light of other findings relating to the actions of the glucocorticosteroids on glucose metabolism.
HORMONAL MODULATION OF HYPOTHALAMIC UNIT ACTIVITY AND EEG RESPONSE TO VAGINAL STIMULATION IN THE DEERMOUSE
Authors: ZOLOVICK A. J. , ELEFTHERIOU B. E. 
Published: December 2008

SUMMARY
The EEG after-reaction to vaginal stimulation occurred during oestrus and was inhibited during dioestrus or abolished by pregnancy or ovariectomy. Hypothalami of oestrous animals were more responsive to vaginal stimulation than the hypothalami of dioestrous or pregnant animals. The increase in the number of responsive neurones in oestrous animals was attributed to an increase in the number of neurones that exhibited a delayed decline in their discharge rate in response to vaginal probing. These neurones were located along the midline in the anterior and basal hypothalamus. Administration of oestrogen to ovariectomized animals was moderately successful in reinstating the delayed inhibitory response of the hypothalamic neurones to vaginal stimulation while the EEG response was almost completely restored. The importance of this hypothalamic activity is discussed in relation to the luteinizing hormone short loop feedback mechanism and the EEG after-reaction.
EFFECT OF REDUCED FOOD INTAKE ON THYROID CELL HEIGHT AND GOITROGENIC RESPONSE IN RATS
Authors: DONIACH I. , SWETTENHAM K. V. 
Published: December 2008

SUMMARY
Adult rats in groups of ten were maintained variously on full, half and quarter food intake. Some were given plain drinking water ad libitum, others were given a goitrogenic challenge of 0·1% aminotriazole (ATA) in the drinking water. Food and fluid consumption were measured daily. The animals were killed after 3 weeks for measurement of thyroid and body weight. The thyroids were histologically examined and epithelial cell height was measured. Another series of rats on normal food intake were given ATA solutions of various concentrations to drink and the efficacy of the concentrations to depress a 16 h thyroid uptake of 131I was measured.
The results showed a reduction in average thyroid cell height parallel to the degree of starvation in the non-ATA treated groups and a reduction in goitrogenic response to equivalent challenge with ATA of about 15% in the half-fed animals and 20–25% in the quarter-fed animals. It is suggested that, in adapting to caloric restriction, higher centres depress the thyrotrophic hormone releasing factor response of the hypothalamus to a fall in circulatory thyroid hormone concentration. The degree of reduction in goitrogenic response might be regarded as a quantitative index of this depression.
GENETIC VARIATION IN ADRENAL WEIGHT IN YOUNG ADULT MICE
Authors: BADR F. M. , SPICKETT S. G. 
Published: December 2008

SUMMARY
Adrenal weight and body weight were measured for 100 mice of each sex of the strains: A/Cam, CBA/FaCam and SF/Cam. This was also done for reciprocal F1 hybrids between A and CBA, for reciprocal backcrosses, and for F2 hybrids. Using regression analysis, adrenal weights were corrected for differences in body weights. Sexes and strains were found to be significantly different with respect to both absolute and corrected adrenal weight. The males of the F1 cross between the A and CBA strains showed partial dominance of the A genotype. Reciprocal F1 females were found to differ significantly. This may be explained in terms of parent-genotype: offspring-genotype interactions.
The variances of the heterogeneous stocks: F2, backcross of F1 to A and backcross of F1 to CBA, were found to be significantly higher than those of the homogeneous stocks: A, CBA and F1's. This indicated that at least some of the variation in relative adrenal weight between the strains was genetically determined. The frequency distributions of the ratio of adrenal weight to body weight in F2 and reciprocal backcrosses conformed to the classical pattern of a metrical character.
ACTIONS OF MAMMALIAN, AVIAN AND PISCINE GONADOTROPHINS IN THE LIZARD
Authors: LICHT P. , HARTREE ANNE STOCKELL 
Published: December 2008

SUMMARY
The gonadotrophic activities of crude glycoprotein fractions from pituitaries of man, sheep, chicken and carp and of partially purified follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the three tetrapod species were examined in both sexes of the lizard Anolis carolinensis. The piscine material did not show activity in the lizard but all mammalian and avian preparations promoted spermatogenesis, ovarian growth, ovulation and steroidogenesis. FSH preparations were far more potent than LH, in fact the actions of the LH preparations may have been due largely to FSH contamination. These findings are consistent with earlier conclusions that FSH alone may be able to stimulate all types of gonadal activity in lizards, except that high doses of FSH block ovulation. Comparisons of the relative potencies of the avian and mammalian preparations provide evidence for the zoological specificity of vertebrate gonadotrophins. In general, the relative potency of chicken gonadotrophins in lizards was greater than that estimated from standard rodent bioassays: i.e. the lizard is relatively more sensitive to chicken gonadotrophin than the rodent.
FUNCTIONAL ZONATION OF ADRENOCORTICAL TISSUE IN THE BRUSH POSSUM (TRICHOSURUS VULPECULA)
Authors: VINSON G. P. , PHILLIPSt J. G. , JONES I. CHESTER , TSANG W. N. 
Published: December 2008

SUMMARY
The relationship of structure and function in the adrenal gland of the possum Trichosurus vulpecula, has been studied using in-vitro incubation techniques. It was shown that both 17α-hydroxycorticosteroids and 17-deoxycorticosteroids were produced from radioactive pregnenolone and progesterone, and that these transformations occurred both in the definitive cortex as well as in a special zone of hypertrophied tissue found only in the adult female.
In support of earlier findings, it was also shown that the adrenal cortex of the possum has a remarkable capacity to produce C19 steroids (including androstenedione and testosterone) from the radioactive precursors. While most of the transformations occurred with equal efficiency in both types of tissue, the reduction of androstenedione to testosterone seemed to take place more readily in the special hypertrophied zone of the adult female.
In studies in vivo, it was found that levels of testosterone in the peripheral blood of the adult female possum were extremely high compared with man. Variations in testosterone levels were not apparently correlated with the stage of the oestrous cycle.
The possible pathways by which the adrenal products are synthesized, and their physiological implications are discussed.
URINARY EXCRETION OF FREE CATECHOLAMINES IN GRAVES' DISEASE
Authors: BAYLISS R. I. S. , EDWARDS O. M. 
Published: December 2008

SUMMARY
As judged by the urinary excretion of free noradrenaline and adrenaline, the secretion of catecholamines is not increased in patients with Graves' disease. Catecholamine excretion was not reduced by treatment with propranolol or carbimazole singly or in combination. The possible mechanism in hyperthyroidism responsible for the apparent increase in sympathetic nervous activity and the mitigation of these features by propranolol is discussed.
EFFECT OF OESTRADIOL ON CELL PROLIFERATION AND HISTOLOGICAL CHANGES IN THE UTERUS AND VAGINA OF MICE
Authors: GALAND P. , LEROY F. , CHRÉTIEN J. 
Published: December 2008

SUMMARY
The duration of the phase of DNA synthesis (S-phase) and turnover times were measured by autoradiography in the vaginal and endo-uterine epithelium of spayed mice at different times after a single oestradiol injection. With three doses of oestradiol (0·3, 1·2 and 10·0 μg), changes of turnover time followed similar patterns in uterine epithelium, but maximal activation and subsequent levelling off of proliferation rates were reached sooner with higher doses. In the vagina, no significant dose-dependence was apparent with the same doses of oestradiol; maximal activation of cell proliferation was observed in every case 12 h after hormone injection.
Transient shortening of S-phase was observed in both tissues under oestrogen stimulation. The morphological changes in uterine epithelium appeared to be independent of mitotic stimulation. For vaginal epithelium, the results may be interpreted to indicate that oestrogen-induced keratinization starts by a differentiating action on pre-existing G1 cells.
THE 'EARLY ANDROGEN SYNDROME' IN THE GUINEA-PIG
Authors: BROWN-GRANT K. , SHERWOOD M. R. 
Published: December 2008

SUMMARY
When testosterone propionate was administered to pregnant guinea-pigs over a short period (days 33–37) of gestation a high proportion of the female offspring exhibited a characteristic syndrome. The time of the first vaginal opening was delayed and its duration reduced. Subsequent periods of opening were fairly regular in occurrence but were shorter in duration than in normal animals; the 'cycle' length was usually slightly longer. Continuous vaginal opening was not observed but during the periods of opening, vaginal smears containing many cornified cells and no leucocytes were obtained. During the periods of vaginal opening no lordosis response to manual stimulation could be elicited nor did the animals mate when run with males. The increase in body weight was normal up to about 150 days of age and slightly, but not significantly, less than that of controls between 150 and 200 days of postnatal life. As adults some masculinization of the external genitalia was observed. At autopsy the weights of the uteri, ovaries, adrenal and anterior pituitary glands were much greater than those of control animals at any stage of the cycle. Histological examination showed that the ovaries contained many antral follicles but no luteal tissue. Enlargement of the glands and metaplastic changes in the epithelium were observed in the uteri. The pituitaries showed an excess of cells containing large, densely packed eosinophilic granules.
This early androgen syndrome is compared with that produced by hypothalamic lesions in the guinea-pig and with the changes produced in other species by the administration of androgenic steroids during prenatal or early postnatal life.
THE EFFECT OF SURGICAL ISOLATION OF THE HYPOTHALAMUS ON REPRODUCTIVE FUNCTION IN THE FEMALE RAT
Authors: BUTLER JEAN E. M. , DONOVAN B. T. 
Published: December 2008

SUMMARY
Surgical isolation of the hypothalamus from the rest of the brain was used in a study of the hypothalamic control of gonadotrophin secretion. Rats with hypothalamic islands of differing sizes and animals in which the hypothalamus was partially deafferentated were prepared. Oestrous cycles were followed by taking daily vaginal smears and the reproductive state assessed from histological examination of the genital tract collected at autopsy 28 days postoperatively. In rats with 'large' and 'long' hypothalamic islands persistent vaginal oestrus ensued and the ovaries were follicular. Rats in which smaller islands disconnected the suprachiasmatic nuclei from the median eminence displayed persistent vaginal dioestrus and the ovaries contained corpora lutea. Rats with frontal cuts placed anterior to the suprachiasmatic nuclei behaved similarly to rats with 'large' and 'long' islands in developing persistent vaginal oestrus, but when the anterior connexions to the hypothalamus were severed caudal to the suprachiasmatic nuclei the animals had oestrous cycles which were sometimes interrupted by periods of dioestrus of pseudopregnancy length. Posterior and transverse cuts in the hypothalamus did not alter the oestrous cycle although there was some indication that luteal function was favoured.