bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE SODIUM AND POTASSIUM CONCENTRATIONS IN THE UTERINE FLUID OF THE RAT AT THE TIME OF IMPLANTATION
Authors: CLEMETSON C. A. B. , KIM J. K. , MALLIKARJUNESWARA V. R. , WILDS J. H. 
Published: December 2008

SUMMARY
Rat uterine fluid Na+ and K+ concentrations were calculated from the ratio of the Na+ and K+ concentrations in uterine washings, on the assumption that the sum of Na+ and K+ (mequiv./l) is the same in blood serum and in uterine fluid. Uterine fluid volumes were likewise calculated from the total quantity of Na+ and K+ washed out of the uterine horn.
The mean uterine fluid volume was 7·6 μl per horn and the mean potassium concentration was 45·8 mequiv./l on day 6 of normal pregnancy. Both oophorectomy alone on day 2 and oophorectomy followed by daily injections of progesterone, cause a marked reduction of the uterine fluid volume on day 6 of pregnancy. Oophorectomy on day 2 caused a significant reduction in the uterine fluid K+ concentration. Administration of high and low doses of progesterone after oophorectomy on day 2 of pregnancy resulted in uterine fluid potassium concentrations higher and lower, respectively, than the normal day 6 fluid.
It is postulated that a high uterine fluid K+ concentration is essential for blastocyst-endometrial contact preceding implantation and that this may be significant with regard to certain types of delayed implantation.
A COMPARISON OF THE COMPETITIVE PROTEIN-BINDING ASSAY AND RADIOIMMUNOASSAY FOR PLASMA PROGESTERONE DURING THE NORMAL MENSTRUAL CYCLE
Authors: MORGAN CHRISTINE A. , COOKE I. D. 
Published: December 2008

SUMMARY
A protein-binding assay for plasma progesterone using 2% aqueous chick plasma as the binding solution is described. Details of specifications for petroleum spirit to extract the plasma are given, no chromatographic step being employed. Bound and free steroid are separated by Florisil. The system will assay plasma progesterone at a concentration of 2·0 ng/ml; other reliability data are evaluated. One technician can assay 12 duplicate plasma samples per day.
The radioimmunoassay method has utilized two antisera, the first, antiprogesterone-20-0-carboxymethyl-oxime—bovine serum albumin at a dilution of 1 in 3000, the second, anti-progesterone-11-succinyl—bovine serum albumin at a dilution of 1 in 10000. Bound and free steroid are separated by dextran—charcoal suspension. The system will assay plasma progesterone at a concentration of 1·0 ng/ml. One technician can assay 24 duplicate plasma samples per day.
There is a good correlation between results obtained by both competitive protein-binding (CPB) and radioimmunoassay (RIA) methods. Both methods have a place in estimating the large numbers of serial samples required in the study of physiological situations, although the RIA method will probably supersede the CPB because of its robustness and greater output.
REGULATION OF THE PERMEABILITY TO WATER IN TOAD URINARY BLADDER: THE EFFECT OF COPPER
Authors: PARISI MARIO , PICCINNI ZULEMA F. 
Published: December 2008

SUMMARY
The effect of Cu2+ in concentrations from 1 × 10−7 to 1 × 10−4 mol/1 on water movement across the toad urinary bladder in vitro was studied. Although Cu2+ did not alter the permeability to water by itself, it strongly inhibited the hydrosmotic response induced by oxytocin and theophylline. This effect was present only when the ion was added to the serosal side. The observed inhibition was not completely reversible even at the lower Cu2+ concentrations. No interaction of Cu2+ with cyclic AMP was observed. However, a reversible inhibitory effect of the ion on the hydrosmotic response induced by increasing tonicity of the medium was demonstrated. In this case Cu2+ was effective from both sides. It is concluded that Cu2+ has two effects: (1) a non-reversible action on the cyclase system, inhibiting the responses to oxytocin and theophylline; (2) a reversible action on the 'osmosensitive mechanism', inhibiting the response induced by increasing tonicity.
THE EFFECTS OF OESTROGEN ON THE CELL CYCLE IN EPITHELIAL AND CONNECTIVE TISSUES OF THE MOUSE UTERUS
Authors: DAS R. M. 
Published: December 2008

SUMMARY
The duration of stages of the cell cycle in the uterine epithelial and stromal tissues of ovariectomized mice was estimated by the labelled mitosis method. In untreated animals the mean duration of the S phase (DNA synthesis) was 10·5 h in the glandular and luminal epithelium. Oestrogen treatment shortened it to 6 h in both tissues. In the endometrial stroma of progesterone-treated mice the duration of S was 8 h; when oestrogen was given it increased slightly. The generation times estimated under steady-state conditions were 270,156 and 383 h respectively in the lumen, glands and stroma of untreated mice. After oestrogen stimulation the responses became highly synchronized.
A SOLID PHASE RADIOIMMUNOASSAY FOR OVINE AND CAPRINE PROLACTIN USING SEPHAROSE 6B: ITS APPLICATION TO THE MEASUREMENT OF CIRCULATING LEVELS OF PROLACTIN BEFORE AND DURING PARTURITION IN THE GOAT
Authors: HART I. C. 
Published: December 2008

SUMMARY
A rapid solid phase radioimmunoassay for ovine and caprine prolactin is described utilizing antibodies chemically bound to Sepharose 6B. Prolactin was measured in blood samples taken from goats at varying intervals before the onset of the first stage of labour. The concentration of prolactin rose 5–35 h before parturition to a level 2·6–4·5 times the lowest concentration found earlier in gestation. The results of serial samples taken during the first and second stages of labour indicate that the intense uterine contractions associated with the expulsion of the kid are associated with a large increase in the level of prolactin in the blood.
INFLUENCE OF AGE ON THE RELEASE OF LUTEINIZING HORMONE INDUCED BY OESTROGEN AND PROGESTERONE IN IMMATURE RATS
Authors: CALIGARIS L. , ASTRADA J. J. , TALEISNIK S. 
Published: December 2008

SUMMARY
In immature female rats serum luteinizing hormone (LH) concentration, as measured by radioimmunoassay, was found to be higher at 10 or 15 days of age than thereafter. Animals ovariectomized soon after birth or at 5 days of age showed a significant rise in serum LH levels 10 days later.
A positive feedback effect on LH secretion was observed on the day following a single injection of oestradiol benzoate (OB) in 28-day-old rats but not in younger animals. However, in animals primed with OB a second dose of OB 2 days later resulted in a significant rise in serum LH levels even in rats of 22 days of age.
Progesterone (1 mg) injected 3 days after the injection of a single dose of OB induced, a few hours later, a significant rise in serum LH concentration. This effect was observed from the 22nd day of age but not in younger animals. The magnitude of the response to progesterone, as revealed by the serum LH levels, sharply decreased at the time of puberty.
It is concluded that the mechanisms responsible for the tonic release of LH are ready to function at the time of birth or shortly thereafter, while those involved in the phasic release mature around 22 days of age.
THE METABOLIC CLEARANCE RATE AND PRODUCTION RATE OF PROGESTERONE AND THE CONVERSION OF PROGESTERONE TO 20α-HYDROXYPREGN-4-EN-3-ONE IN THE SHEEP
Authors: BEDFORD CECELIA A. , HARRISON F. A. , HEAP R. B. 
Published: December 2008

SUMMARY
Tracer kinetic techniques were used to determine the metabolic clearance rate (MCR) and production rate (PR) of progesterone in the sheep during pregnancy, the oestrous cycle and the lactation anoestrus. The MCR from whole blood measured by the continuous infusion of [3H]progesterone was 3·483 ± 0·126 l/min in pregnancy, 2·752 ± 0·239 l/min in the oestrous cycle and 5·020 ± 0·566 l/min in lactation anoestrus. After correcting for body weight the respective values were 0·077, 0·077 and 0·133 l/min/kg. The PR ranged from 0·60 to 6·75 μ/min in the oestrous cycle and 6·66 to 72·14 μg/min in pregnancy. In the last 4 weeks of gestation the PR of progesterone was significantly greater in ewes bearing foetuses with birth weights of more than 4 kg than in ewes with smaller lambs.
The conversion or isotope concentration ratio of progesterone to 20α hydroxypregn-4-en-3-one (20α-diHP) was 69·4±10·0% in non-pregnant and 77·2 ± 4·8% in pregnant sheep. The concentrations of [3H]progesterone and [3H]20α-diHP were closely correlated.
There was an appreciable extraction (25·4 ± 3·0%) of progesterone and production (9·1 ± 2·0% of 20α-diHP by the head.
CORTICOSTEROIDOGENESIS IN ISOLATED ADRENAL CELLS: EFFECT OF ADRENOCORTICOTROPHIC HORMONE, ADENOSINE 3′,5′-MONOPHOSPHATE AND β1–24ADRENOCORTICOTROPHIC HORMONE DIAZOTIZED TO POLYACRYLAMIDE
Authors: RICHARDSON M. C. , SCHULSTER D. 
Published: December 2008

SUMMARY
A cell suspension was prepared from normal rat adrenal tissue by collagenase digestion of decapsulated adrenal glands. Corticosterone produced by these cells was assayed both by competitive protein binding and by radioimmunoassay (range: 0–1 ng; sensitivity: 30 pg). Before incubation, the medium and cells equivalent to one gland contained 27·7 ± 3·2 ng corticosterone which increased to 36·3 ± 7·0 ng corticosterone after 1 h of incubation. Although a normal sigmoid log dose—response curve was obtained using adrenocorticotrophin (ACTH) (ED50:1·2 × 10−4 i.u./ml), it was observed that log (ACTH concentration) was directly proportional to log (corticosterone produced) between 1 × 10−7 and 1 × 10−3 i.u. ACTH/ml. A similar linear relationship was demonstrated for the effect of adenosine 3′,5′-monophosphate on steroidogenesis. Time-course studies revealed that after addition of ACTH there was a definite lag (3 min) before onset of increased steroidogenesis; within 5 min a constant corticosterone production rate was achieved. β1–24 Adrenocorticotrophin was shown to retain its ability to stimulate steroidogenesis when diazotized to beads of polyacrylamide too large to enter cells. Evidence is provided that the activity of the β1–24 ACTH—polyacrylamide beads is not due to biologically active peptides cleaved from the complex.
It is concluded that ACTH can stimulate steroidogenesis without entering its target cells.
STRAIN DIFFERENCES IN TESTICULAR WEIGHT AND SPERMATOGENESIS WITH SPECIAL REFERENCE TO C57BL/10J AND DBA/2J MICE
Authors: SHIRE J. G. M. , BARTKE A. 
Published: December 2008

SUMMARY
Marked differences were found in the absolute and relative weights of the testes of young adult mice from 11 strains. DBA/2J mice had large testes (936 ± 46 mg/100 g body weight) and C57BL/10J mice had small ones (389 ± 6 mg/100 g). Comparisons of mice from these two strains, raised under three different environmental conditions, showed that the difference between the strains was relatively unaffected by environmental variation. Measurements on hybrid mice confirmed that much of the observed difference between the two strains was genetic in origin.
The C57BL/10 mice were unlike those of any of the other strains in that both the relative and the absolute weights of the testis declined between the ages of 9 and 16 weeks.
Strain differences were also found when spermatogenesis was studied in four of the strains by counting the different types of germinal cells in seminiferous tubules in stage VII of spermatogenesis. There were about twice as many type A spermatogonia in DBA/2 mice as there were in C57BL/10 mice. The mean numbers of spermatocytes and spermatids were much greater in DBA/2 than in C57BL/10. These differences were sufficient to account for the observed differences between these strains in testicular weight.
Reciprocal F1 mice resembled their DBA/2 parents both in the weight of their testes and in the pattern of spermatogenesis.
It is suggested that, in comparison with mice of the other strains, C57BL/10J mice may be deficient in androgenic hormones.
DIFFERENCES BETWEEN MOUSE STRAINS IN TESTICULAR CHOLESTEROL LEVELS AND ANDROGEN TARGET ORGANS
Authors: BARTKE A. , SHIRE J. G. M. 
Published: December 2008

SUMMARY
The concentrations of esterified and free cholesterol in the testes, and the weights of the testes, seminal vesicles, kidneys and submandibular glands, were determined in mice of the C57BL/10J and DBA/2J inbred strains. Measurements were also made on reciprocal F1 hybrids. Cholesterol concentration and the weights of the testes and seminal vesicles were also studied in C57BL/6J and AKR/J inbred mice and in mice from two random-bred stocks. Considerable strain differences were found both in the concentration of esterified cholesterol and in gonadal weight. Since all the animals were maintained under the same environmental conditions the differences must have been genetic in origin. The decrease in absolute testicular weight which occurred in the C57BL/10 mice after the age of 8 weeks was accompanied by an increase in the percentage of total cholesterol present as ester. Groups of C57BL/10 males were treated with luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin-secreting pituitary isografts, pregnant mare serum gonadotrophin (PMS), testosterone propionate or pregnenolone. The concentration of esterified cholesterol was slightly decreased by LH and increased by pituitary grafts, confirming earlier studies in other strains. Treatment with PMS caused a drastic depletion of the high levels of esterified cholesterol usually found in the testes of these mice, and also caused marked growth of the seminal vesicles. Testosterone increased the weight of seminal vesicles while pregnenolone had no effect. None of the treatments stimulated spermatogenesis. A marked sex difference in the weight of the kidneys was absent in the C57BL/10 strain but was present in the DBA/2 strain. The kidneys of C57BL/10 males were significantly smaller than those of DBA/2 males. These findings, together with other studies on C57BL/10 mice, suggest that males of this strain are relatively androgen deficient. This could be due to inadequate production of FSH and LH, perhaps accompanied by a deficiency in the conversion of pregnenolone to androgenic steroids. The effect of the C57BL/10 genotype on spermatogenesis either is not hormone mediated or else is irreversible after the age of 6 weeks.
CENTRAL AND PERIPHERAL NEURAL INFLUENCES ON THE OXYTOCIN-INDUCED PRESSURE RESPONSE OF THE MAMMARY GLAND OF THE ANAESTHETIZED LACTATING RAT
Authors: GROSVENOR C. E. , DeNUCCIO D. J. , KING S. F. , MAIWEG H. , MENA F. 
Published: December 2008

SUMMARY
Intramammary pressure responses to intravenous injections of oxytocin were compared in the urethane-anaesthetized rat before and after various denervation procedures and before and after administration of various adrenergic blocking drugs. Intravenous administration of either phenoxybenzamine, propranolol or pentolinium after a period of time resulted in a more quickly ascending, higher amplitude pressure response but which usually returned more slowly — often oscillating — to the pre-existing basal pressure. Unilateral severance of the dorsal roots supplying the six abdomino-inguinal glands resulted in immediate though lesser increases in both the slope and amplitude of the intramammary pressure response. The responses were increased to a similar extent in contralateral as well as ipsilateral glands caudal to the point of root section whereas the responses of glands rostral to the section were unaffected. The effect of dorsal root section persisted unchanged in rats pretreated with either phenoxybenzamine or propranolol. The intramammary pressures also increased immediately when the segmental nerves were cut. The intramammary pressure was decreased in all glands tested after transecting the spinal cord between T-10 and T-11, then increased dramatically in slope and amplitude over the next 1 to 2 h in glands caudal to the level of section; the responses of glands rostral to the level of cord section were unchanged. The resulting high amplitude responses obtained after cord section usually oscillated and were slow to return to pre-existing basal pressures. The intramammary pressure profile changed in a manner similar to that following spinal cord section when 25% KCl was placed bilaterally on the cerebral cortices. The effect of KCl persisted in rats pretreated with phenoxybenzamine and pentolinium. The results obtained from these experiments suggest that a diffuse motor control of ductal and vascular tone exists in the rat mammary gland which appears to be inhibitory in function and to be sensitive to central as well as to peripheral influences.
METABOLISM OF ETHYNYLOESTRADIOL IN MAN
Authors: REED M. J. , FOTHERBY K. , STEELE S. J. 
Published: December 2008

SUMMARY
The metabolism of 17α-ethynyloestradiol was studied in one man and 16 women. After intravenous or oral administration, 22·6–46·9% of the dose was excreted in the urine over a 5-day period. Up to 36% of the urinary radioactivity may be present in the unconjugated form with a further 64% being extractable after enzymic hydrolysis. Sulphate conjugates formed only 11·4% of the urinary radioactivity. Semi-quantitation of these extracts showed ethynyloestradiol itself to be the major metabolite, accounting for 3·2–8·4% of the administered dose in the unconjugated fraction with a further 2·4–16·5% in the enzyme hydrolysed fraction. Up to 16·5% of the dose was therefore excreted unchanged, and metabolites less and more polar than ethynyloestradiol were also found. Excretion via the faeces accounted for up to 30% of the administered dose, with most of the extractable radioactivity being in the unconjugated form. Ethynyloestradiol accounted for up to 29·6% of faecal radioactivity. No significant amounts of radioactivity were detected in sweat collected from one subject 2 or 24 h after administration of the dose. Plasma levels of 3·32% and 1·72% of the administered dose per litre were found 1 and 24 h after administration. Metabolites in plasma were present mainly as sulphate conjugates.
CYCLIC AMP AND THE DIFFERENTIATION OF ADRENAL CORTICAL CELLS GROWN IN TISSUE CULTURE
Authors: MILNER A. JOSEPHINE 
Published: December 2008

SUMMARY
Primary tissue cultures of adrenal cells were prepared from foetal rat adrenals. The effect of cyclic AMP (75 μmol/l) on the morphology and steroid synthetic activity of the cortical cells was examined in order to determine whether cyclic AMP mimics the effects induced by adrenocorticotrophin (ACTH); namely transformation to the differentiated cell type and increase in steroid synthetic activity. Cyclic AMP was found to induce some, but not all, of the changes normally induced by ACTH. In particular, the mitochondria in the cortical cells developed vesicular cristae and there was a proliferation of the smooth endoplasmic reticulum. These two organelles are the principle sites of enzymes involved in steroid synthesis and the ultrastructural transformation was accompanied by an increase in the steroidogenic activity of the cells. However, clear differences in the ultrastructure of the cyclic AMP- and ACTH-treated cells were noted. The effects of cyclic AMP on the ultrastructure of cortical and fibroblastic cells present in the adrenal cultures were found to be dependent upon the cell type.
IMPLANTATION AND ATTACHMENT REACTION OF RAT UTERINE LUMINAL EPITHELIUM AT A HIGH DOSE OF OESTRADIOL
Authors: LJUNGKVIST I. 
Published: December 2008

SUMMARY
The injection of 5 μg oestradiol to progesterone-treated spayed, pregnant rats caused implantation in some rats but not in others. In rats with implantation the epithelium underwent a change similar to that during normal implantation, i.e. an attachment reaction. No attachment reaction was seen in rats without implantation or in progesterone-treated, spayed, virgin rats. The results may support the idea that the attachment reaction is the morphological sign of a receptive uterus and that the reaction is functionally related to the onset of implantation. Further, they indicate that the sensitivity to oestrogen varies between rats during delayed implantation.
THE DISTRIBUTION OF CORTISOL AND ITS RATE OF TURNOVER IN NORMAL AND COLD-STRESSED SHORN SHEEP
Authors: PANARETTO B. A. , VICKERY MARION R. 
Published: December 2008

SUMMARY
Cortisol pools were examined in six shorn sheep before (i.e. control conditions) and during their exposure to a cold, wet environment. Cortisol labelled with tritium was infused until equilibrium concentration [3H(eq)] was reached in the plasma; the infusion was then stopped and the instantaneous concentrations [3H(t)] determined at intervals during the next 20–40 min. A two-pool model was used to calculate results and the rate constants k10, k12 and k21 were used to describe catabolism of hormone from the central pool, movement from the central to the outer pool and in the reverse direction respectively.
In the majority of cases when the fractional concentrations, [3H(t)]/-[3H(eq)], after infusion were plotted against time, curves representing control conditions indicated that the apparent rate of disappearance of cortisol from plasma was faster than from cold-stressed normothermic sheep. The apparent rate of disappearance of cortisol from the plasma of both control and cold-stressed normothermic sheep was faster than when the animals were hypothermic. These results were not obtained in two sheep when they were cold-stressed and normothermic and these are discussed.
The rate constants k10, k12 and k21 obtained in the experiments bore the relation control < cold-stressed normothermic < hypothermic. The total amount of cortisol increased about 4 times, relative to control, when the sheep were cold-stressed and normothermic, and 40 times, relative to control, when they were hypothermic. Pools decreased in one cold-stressed normothermic sheep. Turnover rates were 7·7%, 7·0% and 3·7% of the total pool/min for sheep under control, cold-stressed normothermic and hypothermic conditions respectively.
It is concluded that the greatly increased plasma cortisol concentrations detected in cold-stressed normothermic and hypothermic sheep were associated with great increases in total cortisol, distributed in relatively constant 'spaces' in the body under those conditions.
OVULATION INDUCED BY PREGNANT MARE SERUM GONADOTROPHIN IN THE IMMATURE RAT TREATED NEONATALLY WITH A LOW OR A HIGH DOSE OF ANDROGEN
Authors: UILENBROEK J. Th. J. , ten BOSCH J. J. van der WERFF 
Published: December 2008

SUMMARY
Ovulation-inducing effects of pregnant mare serum gonadotrophin (PMSG) were studied in immature female rats treated on day 5 (day 1 = day of birth) with oil or with 5 or 1250 μg testosterone propionate (TP). The response of rats treated with 1250 μg TP was negligible regardless of the age of the animals and of the dose of PMSG. The response of rats treated with 5 μg TP to PMSG alone was low (36% of rats, with 2·6 ova/ovulating rat), but could be improved by progesterone administration 2 days after PMSG injection (91% of rats, with 14·5 ova/ovulating rat). At every age and dose of PMSG tested the response of animals treated with 5 μg TP to combined PMSG and progesterone treatment was less than that of control animals.
It is concluded that neonatal TP treatment diminishes the release of endogenous ovulating hormone subsequent to PMSG injection. This effect is dependent on the dose of TP used, but already demonstrable in animals treated with 5 μg TP on day 5, which would have been cyclic and fertile after puberty.
Only for the animals treated with 1250 μg TP could a decreased sensitivity of the ovaries to combined administration of PMSG and human chorionic gonadotrophin be demonstrated.