bluuebunny/crossref_metadata_2025_split huggingface dataset:
BIOASSAY OF OXYTOCIN BY CHANGES IN LIGHT PENETRATION THROUGH RAT MAMMARY GLAND TISSUE IN VITRO
Authors: BÍLEK J. , MIKULÁŠ I. , SLABA J. , SKÁLA I. 
Published: December 2008

SUMMARY
A method for the bioassay of oxytocin in the lactating rat mammary gland in vitro is described. The changes in transparency induced by oxytocin in a flat segment of the gland are recorded by means of a CdS photoresistor and a simple Wheatstone bridge. The sensitivity of the assay in routine use is about 0·5–10 μu. oxytocin, the index of precision being about 0·1.
THE PRODUCTION OF 'SULPHATION FACTOR' BY RAT LIVER
Authors: McCONAGHEY P. 
Published: December 2008

SUMMARY
Rat liver when treated with bovine growth hormone produced a humoral factor ('sulphation factor') which stimulated cartilage growth directly; the results indicate that this humoral factor differs from growth hormone.
Perfusion of rat liver and incubation of rat liver slices with bovine growth hormone stimulated the production of 'sulphation factor' as measured by the uptake of 35S into rat cartilage. The liver required a long exposure to the hormone before the 'sulphation factor' was produced and was still capable of 'sulphation factor' production after growth hormone treatment had ceased.
The age and condition of the animal influenced the time necessary for growth hormone to act on the liver and the persistence of its effects. Disruption of liver slices by freezing and thawing, and by homogenization, destroyed their ability to produce 'sulphation factor' on addition of growth hormone.
REGULATION OF STEROID SYNTHESIS IN RABBIT OVARIAN HOMOGENATES BY LUTEINIZING HORMONE, CYCLIC AMP AND PYRIDINE NUCLEOTIDES
Authors: SCOON V. , MAJOR PATRICIA W. 
Published: December 2008

SUMMARY
Luteinizing hormone and cyclic AMP stimulate synthesis of progestational steroids in rabbit ovarian homogenates. Both progesterone and 20α-hydroxypregn-4-en-3-one are produced and, in contrast to ovarian slice preparations, progesterone is the predominant steroid formed.
Steroid synthesis in homogenates from interstitial tissue is stimulated to a greater extent than in homogenates of luteal tissue. Synthesis of these steroids by the homogenates can also be increased by addition of NADP+ and NADPH. The amount and nature of the steroid synthesized varies with the amount of cofactor added and with its form (oxidized or reduced). When both forms of cofactor were added to the system in vitro, the ratio of the oxidized to the reduced form appeared to be important in determining the form of the steroid produced.
BINDING OF LONG-ACTING THYROID STIMULATOR TO 4S THYROID PROTEIN COUPLED TO SEPHAROSE
Authors: SMITH B. R. 
Published: December 2008

SUMMARY
Long-acting thyroid stimulator (LATS) and LATS binding protein (LAA) were made insoluble by coupling to Sepharose-4B. LATS was bound by insoluble LAA and the bound LATS was recovered in high yield by treatment with sodium thiocyanate. Insoluble LATS was bound to LAA but LAA could not be recovered from the complex since it was destroyed under the conditions required to dissociate the LATS—LAA bond. The implications of the results are discussed in relation to the purification of LATS and LAA and the development of a radioimmune type assay for LATS.
EFFECT OF REPEATED OESTROGEN ADMINISTRATION ON OESTROUS BEHAVIOUR IN OVARIECTOMIZED EWES
Authors: SCARAMUZZI R. J. , LINDSAY D. R. , SHELTON J. N. 
Published: December 2008

SUMMARY
The effects of repeated injections of oestradiol benzoate (ODB) on the behavioural oestrous responses of ovariectomized ewes were studied using a pool of 144 animals. Oestradiol benzoate (15·6–421·2 μg) injected at intervals of 4 or 6 days produced a gradual decrease in the number of ewes showing induced oestrous behaviour. The response eventually fell below 10% at which time the ewes were defined to be refractory to oestrogenic stimulation of behavioural oestrus. When a continuous variable was used as a measure of response an immediate effect was observed; after the second injection of ODB the duration of oestrous behaviour decreased while the time to onset of oestrous behaviour showed a corresponding increase when compared with the first injection. However the proportion of ewes responding remained unaltered, indicating that continuous variables are a more sensitive measure of refractoriness. Treatment of refractory ewes with the progestagens progesterone, SC-9880 or Nilevar restored normal oestrous behaviour. These results are interpreted to mean that oestrogens (15–400 μg) act to increase thresholds for subsequent oestrogen stimulation of behavioural oestrus, while progestagens (1–10 mg) act to decrease this threshold.
THE DEVELOPMENT OF A RADIOIMMUNOASSAY FOR ARGININE-VASOPRESSIN: PRODUCTION OF ANTISERA AND LABELLED HORMONE; SEPARATION TECHNIQUES; SPECIFICITY AND SENSITIVITY OF THE ASSAY IN AQUEOUS SOLUTION
Authors: EDWARDS C. R. W. , CHARD T. , KITAU MURIEL J. , FORSLING MARY L. , LANDON J. 
Published: December 2008

SUMMARY
A radioimmunoassay for vasopressin was developed using antibodies produced against conjugated and non-conjugated arginine vasopressin. Despite the fact that the vasopressin molecule has only eight amino acids, cross reactivity studies showed that these antibodies were specific for different amino acid sequences.
Labelled hormone of high specific activity (350–800 μCi/μg) was produced by a modification of the chloramine-T method. Unreacted iodide was removed by the batchwise addition of an ion-exchange resin. Other techniques of purification produced no advantage over this simple method.
Several methods of separating antibody-bound and free hormone were studied. All except chromatoelectrophoresis proved satisfactory. Ammonium sulphate or ethanol precipitation of bound hormone was chosen because of simplicity, speed and reproducibility.
The lower limit of detection of the assay was 80 pg arginine vasopressin/ml diluent buffer. Therefore an extraction and concentration procedure is necessary for the measurement of basal circulating levels of the hormone.
EFFECT OF SOME TRIPHENYLETHYLENES ON OESTRADIOL BINDING IN VITRO TO MACROMOLECULES FROM UTERUS AND ANTERIOR PITUITARY
Authors: SKIDMORE J. , WALPOLE A. L. , WOODBURN J. 
Published: December 2008

SUMMARY
The effects of a series of triphenylethylenes (I.C.I. 46,474, I.C.I. 47,699 and clomiphene isomers A and B) on oestradiol binding to receptors from rat, rabbit and mouse uteri and rat anterior pituitary were studied. Binding of oestradiol to receptors from uteri was inhibited competitively by I.C.I. 46,474. Receptors from uteri of the three species and from rat anterior pituitary have very similar affinities for oestradiol and the four triphenylethylenes. The order of activity of the triphenylethylenes as inhibitors of oestradiol binding is: clomiphene B > I.C.I. 46,474 > I.C.I. 47,699 > clomiphene A. Some correlations are made with the activity of the compounds in vivo.
A RADIOIMMUNOASSAY FOR AVIAN LUTEINIZING HORMONE
Authors: FOLLETT B. K. , SCANES C. G. , CUNNINGHAM F. J. 
Published: December 2008

SUMMARY
A radioimmunoassay for avian luteinizing hormone (LH) is described, using antisera raised against chicken pituitary gonadotrophins of varying degrees of purity, and purified chicken LH for radio-iodination. A postprecipitation double antibody method was developed with a sensitivity to 30–60 pg of purified chicken LH.
The specificity of the method was investigated. Fractions of follicle-stimulating hormone with high biological activity showed little immunological activity, whilst all the fractions of LH tested showed strong immunological potency. Human, ovine and bovine LH showed virtually no cross-reaction.
The method measures immunoreactive LH in 25–200 μl plasma from chickens and quail. The plasma levels correlate well with known physiological processes, being absent in hypophysectomized birds and low in sexually immature quail. When testicular growth begins in quail the level rises eightfold; castration increases it still further while the level is lowered by testosterone. Manipulation of the pituitary-thyroid system in quail did not significantly affect the level of plasma activity.
Estimates of activity are independent of either the antiserum or the iodinated preparation of LH used in the assay.
The antisera used all blocked gonadotrophic activity in vivo.
ISOLATION AND PURIFICATION OF LUTEINIZING HORMONE FROM PORCINE PITUITARY GLANDS
Authors: ANDERSON F. B. , O'GRADY J. E. 
Published: December 2008

SUMMARY
A method is described for the isolation of a purified luteinizing hormone (LH) from the anterior lobes of porcine pituitary glands. This includes fractional precipitation, gel filtration and isoelectric focusing. The preparation, which can be recovered in a fairly short time, is of high potency (equivalent to 3·4 mg standard NIH-LH-B7/mg and 6800 i.u. LH/mg).
FACILITATION OF LUTEINIZING HORMONE SECRETION IN THE FEMALE RAT BY PROGESTERONE
Authors: BROWN-GRANT K. , NAFTOLIN F. 
Published: December 2008

SUMMARY
Progesterone injected intramuscularly at 09.00 h on the day of prooestrus in the 4-day cycle of the rat decreased plasma luteinizing hormone (LH) concentration for 2 to 3 h, but by 5 h after injection had triggered an abrupt, premature, and sustained increase in LH secretion. Between 4 and 5 h after injection sufficient LH had been secreted to raise the plasma LH concentration to more than 20 ng/ml and to induce ovulation in the majority of rats. The facilitatory effect of progesterone on LH secretion could be prevented, or extinguished after it had begun, by the administration of sodium pentobarbitone. The effects observed after administration at the prooestrous stage of the cycle are compared with those seen after progesterone injection under other conditions.
EFFECTS OF PROSTAGLANDIN F2α ON SOME REPRODUCTIVE PROCESSES OF HAMSTERS AND RATS
Authors: LABHSETWAR A. P. 
Published: December 2008

SUMMARY
In an attempt to characterize the endocrine profile of prostaglandin F2α (PGF2α) in relation to the female reproductive system, the compound (racemic form) was administered to hamsters and rats in various reproductive states. The prostaglandin terminated pregnancy when given once a day either subcutaneously (50 μg/hamster) or orally (1·5–2 mg/hamster) from Days 4 to 6 of pregnancy inclusive, or as a single subcutaneous injection (50 μg/animal) on Day 4. In the rat, higher (500 μg/injection) and more frequent (twice daily) s.c. injections were required to get even foetal resorption. Concomitant administration of progesterone (4 mg/animal) in either species protected pregnancy. Prostaglandin F2α terminated pregnancy without interfering with the Pontamine blue reaction, suggesting that its antifertility effects were not mediated by inhibition of implantation. In both hamsters and rats the prostaglandin markedly reduced the size of deciduomata which could be restored to normal by administration of progesterone. Prostaglandin F2α delayed passage of zygotes through the Fallopian tubes in a proportion of rats but failed to accelerate egg transport in rats and hamsters. Furthermore, it caused a marked histological degeneration of the corpora lutea and induced formation of a fresh set of corpora lutea in pseudopregnant, pregnant and pseudopregnant—hysterectomized hamsters. These deleterious effects of prostaglandin were accompanied, in hamsters, by the appearance of freshly ovulated tubal ova. Most of the endocrine effects of PGF2α observed in this study can be accounted for by its luteolytic property.
SKIN VIRILISM IN WOMEN WITH HIRSUTISM
Authors: BURTON J. L. , JOHNSON C. , LIBMAN L. , SHUSTER S. 
Published: December 2008

SUMMARY
Thirteen hirsute women were studied and found to have significantly increased mean rates of sweat and sebum excretion and plasma testosterone concentration compared with control women. These same patients had previously been shown to have an increased total skin collagen content. These findings suggest that the whole skin is virilized in hirsutism. This may be the result of cutaneous androgen synthesis.
ANALYSIS OF THE EFFECTS OF PROGESTERONE ON THE SYNTHESIS OF RNA AND PROTEIN IN THE UTERUS OF THE OVARIECTOMIZED RAT AND ON THE DEVELOPMENT OF AN IODIDE CONCENTRATING MECHANISM
Authors: BROWN-GRANT K. , JOHN P. N. , ROGERS A. W. 
Published: December 2008

SUMMARY
Concentration of radioiodide in the cells of the luminal epithelium of the ovariectomized rat after a single injection of progesterone was abolished by 300 μg cycloheximide/100 g body weight given with or 4 h after the progesterone. Actinomycin D at 32 or 80 μ/100 g body weight given with the progesterone did not inhibit the development of the iodide concentrating mechanism. Oestradiol given 16 h before or 2 h after progesterone inhibited the iodide response in a dose-dependent manner. The incorporation of [3H]uridine into histologically fixed material was significantly increased in all tissues of the uterus 1 h after progesterone. The incorporation of [3H]lysine into histologically fixed material was increased significantly in luminal epithelium at 3 h and in all uterine tissues at 7 and 24 h. These findings are consistent with the view that gene transcription may be stimulated by progesterone, resulting in the synthesis of proteins in the different tissues of the uterus. In the luminal epithelium however, progesterone may also stimulate protein synthesis and the development of the iodide response in the absence of gene transcription.
A COMPARISON OF STEROIDOGENESIS IN VITRO IN TWO TELEOSTS, THE MARINE HERRING, CLUPEA, AND THE FRESHWATER ATLANTIC SALMON, SALMO
Authors: SANGALANG G. B. , TRUSCOTT B. , IDLER D. R. 
Published: December 2008

SUMMARY
Cortisol was the principal steroid biotransformed from [16-3H]pregnenolone incubated with interrenal tissues of the Atlantic herring, Clupea harengus harengus, and of the Atlantic salmon, Salmo salar. Corticosterone was the preferred product from [4-14C]progesterone in herring, and cortisol in salmon. In these two teleosts 3H:14C recrystallization ratios of cortisol produced from the equimolar amounts of precursors at various times of incubation suggested that pregnenolone was the better precursor of cortisol and that the favoured pathway to cortisol was via 17-hydroxylated rather than 17-deoxy intermediates.
It was demonstrated that interrenal tissues of herring and salmon both have the capacity to 17-hydroxylate corticosterone to cortisol; aldosterone was not detected in any of the interrenal incubates. The 17-hydroxylation of 11-deoxycorticosterone to 11-deoxycortisol was shown in vitro by interrenal tissues of the Atlantic salmon, a conversion that has not been previously demonstrated in fish or in normal tissues of other vertebrates. When interrenal tissue of Atlantic salmon was incubated with equimolar amounts of [1,2-3H] 11-deoxycorticosterone plus [4-14C]corticosterone, there was more conversion of 11-deoxycorticosterone to 11-deoxycortisol (0·39%) than of corticosterone to cortisol (0·12%) and only a small amount (1·0%) of the 3H-labelled precursor was associated with corticosterone after 4 h incubation.
Biotransformed cortisol was isolated from both herring and salmon interrenals incubated with each of the following pairs of equimolar substrates: [3H]21-deoxycortisol plus [4-14C]11-deoxycortisol, [3H]21-deoxycortisol plus [4-14C]corticosterone, and [7-3H]11-deoxycortisol plus [4-14C]corticosterone. Isotope ratios of product cortisol suggested that, under the in-vitro conditions employed, substrate efficiency to cortisol synthesis was in the order: 11-deoxycortisol ⪢ 21-deoxycortisol > corticosterone. The results indicated that steroid hydroxylations at C-11, C-17 and C-21 could occur in any order in vitro in interrenals of herring and of salmon.
DETERMINATION OF DEHYDROEPIANDROSTERONE AND DEHYDROEPIANDROSTERONE SULPHATE IN HUMAN PLASMA USING ELECTRON CAPTURE DETECTION OF 4-ANDROSTENE-3,6,17-TRIONE AFTER GAS-LIQUID CHROMATOGRAPHY
Authors: de JONG F. H. , van der MOLEN H. J. 
Published: December 2008

SUMMARY
A method for the measurement of dehydroepiandrosterone (DHA) and of its sulphate (DHAS) in human peripheral plasma is described and evaluated. After isolation of DHA from the sample the steroid is oxidized to 4-androstene-3,6,17-trione, which is measured with an electron capture detector after gas—liquid chromatography. It is possible to detect 100 pg 4-androstene-3,6,17-trione. The smallest amount of DHA per sample that can be distinguished from zero is approximately 4 ng, when recovery (27·9 ± 8·8%) and method blank (0·23 ± 0·38 ng) are taken into account. The oxidation to 4-ene-3,6-diones is specific for steroidal 5-en-3-ols. Specificity for DHA is ensured by several chromatographic steps. Repeated estimation of 10 ng DHA gave a mean value of 9·6 ± 1·45 (s.d.) ng (n = 35). Mean concentrations and their standard deviations for DHA and DHAS in peripheral plasma from 18 individuals were 0·50 ± 0·25 and 78 ± 40 μg/100 ml, respectively, at 08.30 h and 0·32 ± 0·17 and 84 ± 34 μg/100 ml, respectively, at 17.00 h of the same day. Levels of plasma cortisol in the same plasma samples estimated with a competitive protein-binding method were 16·7 ± 1·8 and 11·9 ± 3·8 μg/100 ml, respectively. No significant differences between the sexes were observed by any of the three assays. The mean values of the plasma concentrations of cortisol and DHA in the morning were significantly higher than those in the evening (P < 0·001 and P < 0·005, respectively). In contrast, the mean value of the plasma levels of DHAS in the morning was significantly lower than that in the evening (P < 0·025).
OESTRADIOL CONTENT OF OVARIAN VENOUS BLOOD AND OVARIAN TISSUE IN HYPOPHYSECTOMIZED RATS DURING LATE PREGNANCY
Authors: WAYNFORTH H. B. , ROBERTSON D. M. 
Published: December 2008

SUMMARY
Oestradiol-17β in ovarian venous blood and ovarian tissue was assayed by a competitive protein-binding method. Oestradiol was found in similar amounts in the ovarian vein blood of pregnant rats hypophysectomized on Day 12 and killed on Days 16 and 21 and in pregnant rats sham-hypophysectomized on Day 12 and killed on Day 16. The pituitary therefore plays no part in oestrogen production after mid-pregnancy until some time between Day 16 and Day 21, when it gives rise to an increased ovarian venous blood oestradiol content just before parturition, in intact sham-hypophysectomized rats. It is suggested that this increase is associated with the advent of the post-partum ovulation. The corpus luteum and the extraluteal component of the ovary in hypophysectomized rats autopsied on Days 16 and 21 and in sham-hypophysectomized rats autopsied on Day 16, contain similar amounts of oestradiol within each group. The extraluteal component contains about five times more oestradiol than corpora lutea in sham-hypophysectomized intact rats autopsied on Day 21. The ovaries of these animals also show an increased amount of oestradiol over that of the ovaries in the other three groups. It is suggested that secretion of oestradiol after mid-pregnancy in rats involves concurrently both the corpus luteum and the extraluteal component of the ovary.
COMPARISON OF THE EFFECTS OF VARIOUS AGENTS ON THYROIDAL ADENYL CYCLASE ACTIVITY WITH THEIR EFFECTS ON THYROID HORMONE RELEASE
Authors: KENDALL-TAYLOR PAT 
Published: December 2008

SUMMARY
Intact mouse thyroid glands were used to measure the formation of cyclic [3H]AMP from [3H]adenine, and the release of thyroidal iodine. These two parameters of thyroid activity responded to similar concentrations of human thyroid-stimulating hormone (TSH). Both were stimulated by prostaglandin E1, although the response was always very much less than to TSH. Both were inhibited by NaF, which appeared to have a toxic effect on the gland. The response to TSH was in each case reduced by lithium, suggesting that the antithyroid effect of Li+ is associated with a direct action on adenyl cyclase; however, Li+ also reduced thyroidal hormone secretion induced by dibutyryl cyclic AMP and may therefore have a second site of action.
In general, the effects of these agents on cyclic [3H]AMP formation correlated well with their effects on thyroidal iodine release. The results support the hypothesis that the activation of adenyl cyclase is closely associated with, and precedes, thyroid hormone secretion.
PRODUCTION OF PROSTAGLANDINS BY THE GUINEA-PIG UTERUS
Authors: POYSER N. L. 
Published: December 2008

SUMMARY
The production of prostaglandins by the uterus and the resting levels of prostaglandins in the uterus on selected days of the oestrous cycle were determined in guinea-pigs.
Prostaglandin F2α was detectable in the guinea-pig uterus in small amounts on days 13, 14 and 15 of the cycle. Prostaglandin E2 was present in even smaller amounts on days 14 and 15. The homogenized guinea-pig uterus had the ability to biosynthesize prostaglandins, from endogenous precursors, during incubation on every day of the cycle studied. Four to six times more prostaglandin F2α than E2 was produced on any one day with the amounts of prostaglandins formed increasing towards the end of the oestrous cycle. Indomethacin inhibited the biosynthesis of prostaglandins by the guinea-pig uterus. The implications of these findings are discussed.
VARIABILITY OF TOTAL PLASMA OESTRIOL IN LATE HUMAN PREGNANCY
Authors: MASSON G. M. , WILSON G. R. 
Published: December 2008

SUMMARY
There was no diurnal variation in plasma oestriol and diet, exercise and rest did not affect plasma oestriol levels in pregnant women. The 30-min, 3-h and day-to-day coefficients of variation compared favourably with that of 48-h urinary excretion.
HUMAN CHORIONIC SOMATO-MAMMOTROPHIN IN SERUM AND URINE IN VARIOUS STAGES OF PREGNANCY: ITS CORRELATION WITH ENZYMES AND OESTROGENS
Authors: BISWAS S. , HINDOCHA P. , DEWHURST C. J. 
Published: December 2008

SUMMARY
Human chorionic somato-mammotrophin (HCS) and the activities of heat-stable alkaline phosphatase (HSAP) and cysteine aminopeptidase (CAP) in the serum of normal pregnant women were studied. The hormone and enzymes were detectable at the early stage of pregnancy and all showed an increase with the progress of gestation. A highly significant correlation was found between HCS and activities of HSAP and CAP during all stages of gestation.
Human chorionic somato-mammotrophin and oestrogens were measured in the urine of pregnant women. The correlation coefficient between these factors was smaller than that found between serum enzymes and HCS but was still significant.
PLASMA TESTOSTERONE AND ACCESSORY SEX GLANDS IN NORMAL AND CRYPTORCHID RATS
Authors: LLOYD B. J. 
Published: December 2008

SUMMARY
Plasma testosterone concentration and the weights of the seminal vesicles and ventral prostate gland were measured in normal and cryptorchid Fischer rats at 3, 4·5, 7·5 and 13·5 months of age, and in normal parabionts and cryptorchid parabionts of 13·5 months of age. Testosterone was measured individually by a protein-binding method. In normal rats, all parameters rose to a maximum at 7·5 months of age, then levelled off or declined at 13·5 months of age. In cryptorchid rats, a similar pattern at a lower level was found for accessory sex gland weight, but plasma testosterone levels showed a progressive decline from an above normal level at 3 months to a subnormal level at 13·5 months of age. Cryptorchid parabionts were less responsive to gonadotrophin stimulation from union with a castrated partner than normal parabionts. The present study showed that plasma testosterone levels in normal and cryptorchid rats are age-related. It also showed that the pattern of plasma testosterone levels observed in cryptorchid rats is different from that seen in normal rats. Accessory sex gland weight is also age-related but is not a reliable index of plasma testosterone levels.