bluuebunny/crossref_metadata_2025_split huggingface dataset:
BODY WEIGHT AND FOOD CONSUMPTION OF LACTATING RATS NURSING VARIOUS SIZES OF LITTERS
Authors: ÔTA K. , YOKOYAMA A. 
Published: December 2008

SUMMARY
Changes in body weight and food consumption during lactation in rats nursing various sizes of litters were studied. The rate of increase in body weight of the mother rats during the experimental period (day 3–14 of lactation) was very similar in mothers with different numbers (2, 4, 8 and 12) of suckling pups/litter. It is suggested that the weight increase of adult female rats during lactation is related more closely to the alteration of ovarian function caused by the suckling stimulus than to the enhanced food intake during this period. Both the food intake of mother rats and the daily gain in weight of litters increased as the number of suckling pups/litter increased and as lactation advanced. Linear relationships were observed between the logarithm of the litter size and both the food intake of the mother rats and the weight gain of the litters. The presence of a close correlation between the food intake of mother rats and the quantity of milk produced by them is suggested.
REGRESSION OF CORPORA LUTEA IN UNILATERALLY PREGNANT GUINEA-PIGS
Authors: OXENREIDER S. L. , DAY B. N. 
Published: December 2008

SUMMARY
Corpora lutea of unilaterally pregnant guinea-pigs regressed in the ovary adjacent to a non-gravid uterine horn while luteal maintenance occurred in the opposite ovary adjacent to a gravid horn. Severence of the utero-ovarian vascular and tissue connexions of the non-gravid uterine horn prevented unilateral regression during unilateral pregnancy and also appeared to cause asynchronous maintenance of cyclic corpora lutea that prolonged the length of oestrous cycles. Unilateral hysterectomy also prevented luteal regression during unilateral pregnancy.
One-third of the females in which the vascular and tissue connexions between the ovary and non-gravid horn were left intact did not contain corpora lutea in the ovary adjacent to the non-gravid horn. Most of the remaining females in the same treatment groups contained smaller corpora lutea in the ovary adjacent to a non-gravid horn than in the ovary adjacent to a gravid horn.
The presence of a sterile uterine horn tended to cause a decrease in the size of corpora lutea located in the contralateral ovary during the last half of pregnancy.
STEROIDOGENIC EFFECTS OF LUTEINIZING HORMONE AND PROLACTIN ON THE RAT OVARY IN VIVO
Authors: YOSHINAGA K. , GRIEVES SUSAN A. , SHORT R. V. 
Published: December 2008

SUMMARY
Progesterone and 20α-dihydroprogesterone were measured in the ovarian venous blood of rats in early pro-oestrus, late dioestrus, day 5 of pseudopregnancy, and in androgen-treated animals with persistent oestrus. Little progesterone was secreted in early pro-oestrus or persistent oestrus (0·1 μg./hr.), but the secretion rose in dioestrus (2·1 μg./hr.) and in pseudopregnancy (7 μg./hr.). The 20α-dihydroprogesterone secretion was low in the persistent oestrous group; in all the other groups it was 1·5–3 μg./hr.
Treatment with luteinizing hormone increased progesterone secretion within 30 min. in pro-oestrus and persistent oestrus, had no significant effect in dioestrus, and depressed it markedly in pseudopregnancy. It appeared to have no significant effect on 20α-dihydroprogesterone secretion except during pseudopregnancy, when it was depressed.
Treatment with prolactin produced no effect within 30 min.in pro-oestrous, dioestrous or pseudopregnant animals.
A NEW IN VITRO ASSAY FOR THYROIDSTIMULATING HORMONE
Authors: BROWN JILL , MUNRO D. S. 
Published: December 2008

SUMMARY
A new in vitro assay for thyroid-stimulating hormone (TSH) is described. The parameter of TSH action is the discharge of radioactive iodine from mouse thyroid glands labelled with 131I in vivo. The assay is sensitive to human TSH and gave consistent results during 1 yr. without seasonal variation. A potent preparation of long-acting thyroid stimulator gave a dose-response line parallel with human TSH. Fresh human serum was toxic to the assay preparation so that circulating TSH levels cannot be measured.
PREPARATION OF GONADOTROPHIN AND GROWTH HORMONE FROM HUMAN PITUITARIES FOR CLINICAL USE
Authors: BROWN J. B. , CATT K. J. , MARTIN F. I. R. 
Published: December 2008

SUMMARY
A procedure for extracting both gonadotrophin and growth hormone from acetone-dried pituitary powder in a form suitable for clinical use is described. Gonadotrophin is extracted first and fractionated by ethanolic precipitation; growth hormone is then extracted from the residues by a modification of Raben's procedure. The yields and potency of the products are given with particular emphasis on their activities in man. The economy of the preparation of gonadotrophin and growth hormone from human pituitaries is discussed.
URINARY OESTROGEN EXCRETION AFTER METYRAPONE ADMINISTRATION TO PATIENTS WITH THE POLYCYSTIC OVARY SYNDROME
Authors: SFIKAKIS A. P. , IKKOS D. G. , DIAMANDOPOULOS K. N. 
Published: December 2008

SUMMARY
The 24 hr. urinary excretion of oestrone, oestradiol and oestriol was measured during metyrapone administration in six normal women, four patients with primary amenorrhoea, six patients with polycystic ovary syndrome (POS) and three patients with secondary amenorrhoea. In the six normal women the oestrogen excretion on the first and second day of metyrapone administration did not differ from the control values except for a slight, probably significant, decrease in the excretion of oestradiol on the first day. In the patients with primary and secondary amenorrhoea the results were similar to those in the normal women. In the POS group the urinary excretion of oestrogens increased by 11–120% on the first day of metyrapone administration and by 63–140% on the second day. Studies with metyrapone in three patients with POS during dexamethasone suppression and/or ACTH administration suggest that the increased oestrogen excretion after metyrapone depended on the usual feedback mechanism between the adrenal and the hypothalamo-hypophysial system.
Possible reasons for the absence of this increase in the normal subjects are discussed. It is concluded that the abnormal response to metyrapone in patients with the POS was not due to the amenorrhoea per se and the possibility that this response was related to the underlying disorder of POS is considered.
CHANGES IN THE DENSITY AND PROGESTERONE CONTENT OF LUTEAL TISSUE IN THE EGYPTIAN BUFFALO DURING THE OESTROUS CYCLE
Authors: EL-SHEIKH A. S. , SAKLA FRANÇOIS B. , AMIN SAFAA O. 
Published: December 2008

SUMMARY
The histological and functional changes of 31 corpora lutea of Egyptian buffaloes during the various phases of the oestrous cycle were studied. The volumes of the corpora lutea were calculated, the volume per cell, the cell volume and the volume of the intercellular spaces were estimated from transverse serial sections stained with haematoxylin and eosin, Mallory's triple stain or van Gieson's stain. The nuclear volumes were also determined and the cytoplasmic volume was calculated. The progesterone content was estimated using column absorption chromatography and a counter-current distribution system.
It was concluded that the luteal cells increase both in volume and in number due to mitosis. The luteal cells decrease in volume after the 15th day after ovulation, the cells lose their distinct outlines in the regressive stage and disappear completely in the corpus albicans. There was a parallel increase in luteal cell volume and progesterone content until the 15th post-ovulatory day followed by a decrease in the regressive phase and disappearance of the hormone in the corpus albicans. A highly significant correlation (r = +0·875) was found between the progesterone content and the cytoplasmic volume. Progesterone concentration/g. luteal tissue increased from the corpus haemorrhagicum to the mature corpus luteum, decreased in the regressive corpus luteum and completely disappeared in the corpus albicans.
OESTROGEN SYNTHESIS IN VITRO BY OVARIES FROM RATS IN DIFFERENT PHASES OF THE OESTROUS CYCLE
Authors: OAKEY R. E. , STITCH S. R. 
Published: December 2008

SUMMARY
Ovaries taken from rats in oestrus converted more [4-14C]testosterone to [14C]oestrone and [14C]oestradiol-17β than did ovaries taken at dioestrus. Little difference was found in the conversion of [4-14C]androst-4-ene-3,17-dione to [14C]oestrone by either type of tissue.
These results suggest that testosterone, rather than androstenedione, is an endogenous oestrogen precursor in the rat.
The ability of the rat ovary to produce oestrogen in vitro from C-19 steroids during dioestrus is discussed.
GEL FILTRATION OF OESTROGEN CONJUGATES IN BOVINE URINE
Authors: MIKLOSI S. A. , McCOSKER P. J. 
Published: December 2008

SUMMARY
A chromatographic method for the purification of oestrogen conjugates in bovine urine is described.
The sample is made 1·0 m in NaCl and applied to a 45 × 6·2 cm. column of Sephadex G-25. Elution with water results in a constant and reproducible retardation and simultaneous purification of the urinary conjugates. Authentic oestrogen conjugates and radioactive urinary metabolites were used in the experiments. The extent of purification and values for recovery are presented and the use of activated charcoal for preliminary decolorization is described.
METABOLISM AND TISSUE DISTRIBUTION OF NORETHISTERONE AND NORGESTREL IN RABBITS
Authors: KAMYAB SORAYA , LITTLETON PHORNPHIMOL , FOTHERBY K. 
Published: December 2008

SUMMARY
After injection of [4-14C]norethisterone or norgestrel labelled with 14C in the ethynyl group into rabbits, 45% and 57·4% of the radioactivity was excreted in the urine, mostly within 2 days. Although small amounts of radioactivity were excreted in the expired air of rabbits receiving norgestrel, little metabolism of the ethynyl group occurred. Radioactivity in plasma declined quickly after injection and 24 hr. later less than 0·5% of the dose remained in the circulation. Up to 5 hr. after injection large amounts of radioactivity were found in liver, kidney, intestine and bile; a large proportion of the dose appeared to undergo an entero-hepatic circulation. Although the concentration in fat and muscle was low the total amount in these tissues may approach 5%. The uterus contained a high concentration of radioactivity suggesting that this tissue may bind the progestins or their metabolites. By 24 hr. the amount of radioactivity in the tissues had markedly decreased. Small amounts of radioactivity crossed the placenta of pregnant animals near term and small amounts were found in the foetus and amniotic fluid. Within 3 hr. of the injection at least half of the radioactivity in the tissues was in a conjugated form and considerable metabolism of the injected progestins had occurred. Little, if any, norethisterone or norgestrel was present in the tissues. The metabolites of norethisterone were mainly polar compounds showing that hydroxylation of the steroid had occurred, whereas the metabolites of norgestrel appeared to be similar to the compounds produced by partial or complete reduction of the α,β-unsaturated ketone grouping in ring A.
THE INCORPORATION OF TRITIATED URIDINE IN THE GENITAL TRACT OF THE OESTROGEN-TREATED MOUSE
Authors: MILLER B. G. , EMMENS C. W. 
Published: December 2008

SUMMARY
The uptake of uridine in vivo into uterine and vaginal RNA after intravenous administration provides a sensitive measure of early oestrogenic effects in the ovariectomized mouse. The response of the uterus to a dose of 0·05 μg. of oestradiol increases rapidly to about tenfold at 8–16 hr., and returns to control levels by 32 hr. In the vagina the response develops more slowly, being maximal at 16–24 hr. The relative potencies of oestradiol, oestrone, oestriol, diethylstilboestrol and meso-hexoestrol tested by this criterion at 4 hr. were similar to those obtained in the 6-hr. water imbibition test.
THE EFFECT OF ALDOSTERONE AND ADRENALECTOMY ON THE ELECTRICAL POTENTIAL DIFFERENCE OF RAT COLON AND ON THE TRANSPORT OF SODIUM, POTASSIUM, CHLORIDE AND BICARBONATE
Authors: EDMONDS C. J. , MARRIOTT JANE C. 
Published: December 2008

SUMMARY
The effect of adrenalectomy on the increase of the transmucosal potential difference (p.d.) of the colon of the rat induced by Na depletion, together with the action of aldosterone on the p.d. and on colonic Na+ and Cl− transport, and K+ and bicarbonate secretion have been investigated. Adrenalectomy increased the Na+ content in the stool, an effect reversed by treatment with aldosterone. When Na+-depleted rats were adrenalectomized and maintained on cortisone, the elevated p.d. fell to levels below those found in normal rats. Aldosterone given intravenously (i.v.) in physiological doses increased the p.d. in normal, adrenalectomized and Na+-depleted adrenalectomized rats after a latency period of 80–110 min., and the p.d. tended to rise further when injections were continued for several days. The p.d. gradient along the colon after treatment with aldosterone was similar to that of Na+-depleted rats, the highest p.d. being at the distal end of the descending colon. Cortisol intravenously increased the p.d. but the effect was small in comparison with that of aldosterone.
Measurement of ionic fluxes in the descending colon of adrenalectomized rats showed that treatment with aldosterone produced an increase in Na+ and water absorption, and in K+ secretion, but had no effect on bicarbonate secretion. The effects of aldosterone on the transmucosal p.d. and ion transport were similar to those of Na+ depletion.
THE LOCALIZATION OF [3H]ALDOSTERONE AND [3H]CORTISOL WITHIN RENAL TUBULAR CELLS BY ELECTRON MICROSCOPE AUTORADIOGRAPHY
Authors: WILLIAMS M. A. , BABA W. I. 
Published: December 2008

SUMMARY
Microgram quantities of tritiated aldosterone or cortisol were injected into the aorta of rats. The kidneys were removed at various times after injection, and examined by light and electron microscope autoradiography. The mineralocorticoids or their metabolites were bound to kidney cells in amounts sufficient to give autoradiographs. Radioactivity occurred mainly in the proximal and distal convoluted tubules. Within these cells it was bound mainly to mitochondria and plasma membranes. The results are discussed in relation to the current theories of mineralocorticoid action.
STEROID SECRETION BY THE ADRENAL GLAND OF FOETAL AND NEONATAL SHEEP
Authors: ALEXANDER D. PAULINE , BRITTON H. G. , JAMES V. H. T. , NIXON D. A. , PARKER R. A. , WINTOUR E. MARELYN , WRIGHT R. D. 
Published: December 2008

SUMMARY
From the left adrenal of ten sheep foetuses and four lambs aged from 110 days after conception to 14 days after birth, adrenal venous blood was collected and assayed for cortisol, corticosterone and aldosterone. These steroids were secreted at all ages but the rate of secretion was greatly increased toward term and after birth. The increase coincided with morphological changes in the adrenal gland. At no stage was the rate significantly increased by corticotrophin, and in two young foetuses it was not decreased by dexamethasone. In two foetuses and one lamb, angiotensin II did not increase the rate of secretion of any of the three steroids significantly, and the blood pressure was raised only in the lamb. It is probable that the secretion of the steroids was maximal under the conditions of the experiments.
THE EFFECT OF ANTERIOR PITUITARY HORMONES ON CARBOHYDRATE METABOLISM IN VITRO IN THE PREPUBERTAL RAT OVARY
Authors: MAJOR PATRICIA W. , ARMSTRONG D. T. 
Published: December 2008

SUMMARY
Small doses of luteinizing hormone (LH) have been shown to exert a stimulating effect on the in vitro carbohydrate metabolism of the prepubertal rat ovary. In order to determine the specificity of the response, studies were undertaken comparing the effects caused by LH with those of other anterior pituitary hormones. Preparations of thyroid stimulating hormone (TSH) caused responses similar to those caused by LH, when added to the media in which prepubertal rat ovaries were incubated. A detailed study of the effects of TSH preparations (prepared by different procedures with known low levels of LH contamination) on lactic acid production, has been undertaken. All TSH preparations tested caused considerably greater stimulation of glycolysis than could be accounted for on the basis of their contamination with LH when the latter was appraised by the ovarian ascorbic acid depletion assay.
FURTHER OBSERVATIONS ON THE KOBER COLOUR AND ITTRICH FLUORESCENCE REACTIONS IN THE MEASUREMENT OF OESTRIOL, OESTRONE AND OESTRADIOL
Authors: BROWN J. B. , MACNAUGHTAN CAROLINE , SMITH MARGERY A. , SMYTH BARBARA 
Published: December 2008

SUMMARY
Higher temperatures allow lower sulphuric acid concentrations and shorter heating times to be used in the Kober colour reaction for oestrogens. A one-stage reaction which is completed in 5 min. at 120° is described for oestrone and oestradiol, and a two-stage reaction which requires two periods of heating for 5 min. at 120° is described for oestriol. The conditions were applied to the Ittrich fluorescence procedure. A spectrophotofluorimetric correction was developed in which fluorescence was measured at wavelengths for excitation and emitted light near the optima for the oestrogens and at another combination at which the oestrogens produced virtually no fluorescence whereas that of impurities was not diminished. Extraction, centrifugation and fluorimetry were performed in specially designed cells. The sensitivity is 0·05–0·1 ng./sample with a linear response up to 300 ng. and a precision better than 4% in the range 1·0–100 ng.
HISTOCHEMICAL DISTRIBUTION OF SOME HYDROXYSTEROID DEHYDROGENASES IN THE PLACENTA, FOETAL MEMBRANES AND UTERINE MUCOSA OF THE MOUSE
Authors: BOTTE V. , TRAMONTANA S. , CHIEFFI G. 
Published: December 2008

SUMMARY
The placenta, foetal membranes and uterine mucosa of mice (pregnant for 8–17 days) have been investigated by histochemical methods for NAD-dependent 3β-hydroxysteroid dehydrogenase (3β-HSDH), and for NAD-and NADP-dependent 17α- and 17β-hydroxysteroid dehydrogenases (17α- and 17β-HSDH), 11α- and 11β-hydroxysteroid dehydrogenases (11α- and 11β-HSDH), and 20β-hydroxysteroid dehydrogenase (20β-HSDH).
3β-HSDH was found to be distributed in the trophoblastic giant cells of the first generation with both pregnenolone and DHA as substrates, and in the giant cells of the second generation and of the labyrinth and the endodermal cells of the inverted yolk sac placenta, but only with DHA as substrate.
17α-HSDH and 17β-HSDH, NAD-dependent, were present in both the first and second generation giant cells and in the giant cells of the labyrinth as well as in the endodermal cells of the inverted yolk sac placenta. With NADP as cofactor, 17α-HSDH and 17β-HSDH were weakly positive with all the substrates used in the giant cells of the second generation and of the labyrinth, while NADP-dependent 17β-HSDH was present in the first generation giant cells and in the endodermal cells of the inverted yolk sac placenta but only with oestradiol-17β as substrate.
The histochemical reaction for 11α-HSDH, both NAD- and NADP-dependent, was limited to trophoblastic giant cells of the second generation and of the labyrinth; 11β-HSDH, both NAD- and NADP- dependent, was distributed in the giant cells of the second generation and of the labyrinth, the epithelial cells of the uterine mucosa and the decidua basalis.
The histochemical reaction for 20β-HSDH, NAD- and NADP-dependent, was weakly positive in the giant cells of the first generation only.
EFFECT OF THE PITUITARY INHIBITOR I.C.I. 33,828 (METHALLIBURE) ON THE REPRODUCTIVE SYSTEM OF MALE RATS
Authors: HEMSWORTH B. N. , JACKSON H. , WALPOLE A. L. 
Published: December 2008

SUMMARY
Impairment of pituitary function in male rats by I.C.I. 33,828 (1-α-methylallylthiocarbamoyl-2-methylthiocarbamoylhydrazine; methallibure) caused arrest of sperm iogenesis beyond step 8, without apparently interfering with the timing of the cycle of the seminiferous epithelium. In this respect there was a close similarity between the effect of the drug and that of hypophysectomy. Uninterrupted daily administration was required and after cessation of treatment, pituitary function was rapidly restored. The antifertility effect of the compound in male rats is due to reduced libido, arrest of spermiogenesis and possibly the induction of 'lethal mutations' in developing germ cells.
PLASMA INSULIN AND GROWTH HORMONE DURING 22-HOUR FASTS AND AFTER GRADED GLUCOSE LOADS IN SIX HEALTHY ADULTS
Authors: HUNTER W. M. , WILLOUGHBY J. M. T. , STRONG J. A. 
Published: December 2008

SUMMARY
Plasma insulin and growth hormone were measured by radioimmunoassay in healthy adults during the latter part of 22 hr. fasts and after graded glucose loads. The insulin concentration was less than 8 μ-u./ml. in all fasting samples and in samples taken after the blood glucose had returned to fasting levels. Insulin levels increased with increasing glucose loads.
During fasting, growth hormone showed intermittently raised secretion; in some subjects high values were reached at times which could not be related to external events or to stress. Growth hormone levels were consistently low during the absorption of glucose but rose immediately thereafter. This rise occurred increasingly late and reached increasing levels as the glucose loads were made progressively larger.
Insulin had almost invariably returned to fasting levels before the growth hormone concentrations began to rise.
OVULATION FOLLOWING VAGINAL STIMULATION IN A SPONTANEOUS OVULATOR AND ITS IMPLICATIONS
Authors: ZARROW M. X. , CLARK J. H. 
Published: December 2008

SUMMARY
Ovulation was blocked in pregnant mare serum-treated immature rats by treatment with chlorpromazine. Reflex ovulation and hence luteinizing hormone release was induced by three procedures: (a) placing male rats with the treated females overnight, (b) mechanical stimulation of the vagina and cervix with a glass rod, and (c) electrical stimulation of the uterine cervix. Mating or mechanical stimulation induced ovulation in 77 and 82% of the rats, respectively. Electrical stimulation was least effective, causing ovulation in only 50%. The average number of ova released and the percentage of rats ovulating was found to be a function of the amount of mechanical stimulation with the glass rod. Pelvic neurotomy abolished the reflex ovulatory response. The stronger response obtained by coitus or mechanical stimuli indicated the possibility of receptor sites in the vaginal wall. This assumption was supported by the finding of penile spines in the rat. A survey of the literature indicates that penile spines are present in a variety of mammalian orders including the primates. The evolutionary relationships and implications of the existence of penile spines and reflex ovulation are discussed. It is suggested that man, like the rat and probably other species which ovulate spontaneously, also has the ability to ovulate after stimulation of the vaginal tract.