bluuebunny/crossref_metadata_2025_split huggingface dataset:
MONOAMINEOXIDASE INHIBITION AND INSULIN SENSITIVITY
Authors: ADNITT P. I. 
Published: December 2008

SUMMARY
Insulin sensitivity was increased in rats treated for 21 days with mebanazine, 10mg./kg., phenelzine, 30mg./kg., or tranylcypromine, 10 mg./kg. but not in rats treated with isonicotinic acid hydrazide, 10 mg./kg., for 21 days or in animals treated with a single injection of mebanazine, 10 mg./kg. Pargyline, 14 mg./kg., given for 21 days produced 83% inhibition of hepatic monoamineoxidase and had a hypoglycaemic action when compared with 0·15 mg. mebanazine/kg., a dose just less than that required to inhibit monoamineoxidase. Increased insulin sensitivity seemed to be related to chronic inhibition of monoamineoxidase rather than to administration of hydrazine derivatives.
There was a tendency to anorexia during the drug treatment, but rats treated with monoamineoxidase inhibitors gained less weight than pair-fed control animals. This could be due to the previously reported reduction in growth hormone activity during treatment with monoamineoxidase inhibitors; nevertheless, any explanation for the increase in insulin sensitivity should be based upon the monoamineoxidase-inhibiting action of these drugs.
PLASMA TESTOSTERONE IN WOMEN IN LATE PREGNANCY AND AFTER DELIVERY
Authors: DEMISCH K. , GRANT J. K. , BLACK W. 
Published: December 2008

SUMMARY
The concentration of testosterone was measured in the plasma of 16 healthy women in late pregnancy and in 14 of these after delivery. The mean testosterone concentration was found to be elevated in late pregnancy, although the range overlapped with the normal. There was a prompt return to normal concentrations after delivery. The significance of the results and of inactivation of testosterone by protein binding are discussed.
TISSUE AND SERUM CREATINE KINASE ACTIVITY IN HYPOTHYROID RATS
Authors: NUTTALL F. Q. 
Published: December 2008

SUMMARY
In rats made hypothyroid by thyroidectomy, serum creatine kinase (CK) activity appears to be unchanged or slightly reduced. This is in contrast to the increased values reported in myxoedematous man. Brain CK activity was unchanged and heart activity was only slightly reduced in these animals. Skeletal muscle CK activity, however, was more definitely reduced and the reduction was highly significant. The lower tissue enzyme activity in heart and skeletal muscle could be explained by a reduction in total protein concentration of the tissue extracts from the thyroidectomized animals, since the specific activity of the enzyme from these tissues was essentially unchanged as compared with controls.
COMPARATIVE EFFECTS OF THE OESTROGENS AND OTHER STEROID HORMONES ON SERUM LIPIDS AND PROTEINS IN XENOPUS LAEVIS DAUDIN
Authors: REDSHAW M. R. , FOLLETT B. K. , NICHOLLS T. J. 
Published: December 2008

SUMMARY
A comparison has been made between the effects of oestradiol-17β, oestrone, oestriol, progesterone, testosterone and cortisone on the plasma concentration of proteins and lipids in the South African clawed toad, Xenopus laevis Daudin. No major changes in the parameters studied were found with the non-oestrogenic steroids; only the three oestrogens induced the appearance in the plasma of a calcium-binding phospholipoprotein and esterified lipids associated with yolk formation. These results support the hypothesis that the oestrogens alone cause the vitellogenic response in oviparous vertebrates.
Dose—response curves for oestradiol-17β, oestrone and oestriol were established for the effects on plasma protein, calcium, protein-bound phosphorus, phospholipid, lipid and cholesterol. The curves obtained were log.-linear over the range of doses employed (oestradiol-17β, 1–50 μg./day; oestrone, 4–100 μg./day; oestriol, 20–500 μg./day) with the exception of the cholesterol response to oestradiol. The relative potencies of the three oestrogens were compared for each of the plasma components measured. Oestradiol-17β was the most potent, being 3·9 times more active than oestrone and 13·7 times more active than oestriol.
EVIDENCE FOR THYROCALCITONIN BINDING TO PROTEIN IN PLASMA
Authors: LEGGATE J. , CARE A. D. , FRAZER S. C. 
Published: December 2008

SUMMARY
A simple method is described for concentrating thyrocalcitonin from plasma by adsorption onto finely divided silica gel. An approximately 20-fold increase in biological activity with respect to protein content has been obtained with recoveries of added material of about 80%, allowing subsequent fractionation and bioassay of the fractions.
Porcine thyrocalcitonin was added to either porcine or human plasma to give concentrations within the range observed in porcine thyroid venous plasma. Concentration on silica gel followed by gel filtration on Sephadex G 50 resulted in separation of the biological activity into two fractions, one of which was associated with the plasma proteins. A similar result was obtained with porcine thyroid venous plasma containing endogenous thyrocalcitonin. Preparative ultracentrifugation of plasma rich in thyrocalcitonin also provided evidence suggestive of some protein binding of the hormone. It is concluded that thyrocalcitonin is carried in plasma partly free and partly bound to plasma protein.
THE RELEASE, CLEARANCE AND PLASMA PROTEIN BINDING OF OXYTOCIN IN THE ANAESTHETIZED RAT
Authors: FABIAN MIRIAM , FORSLING MARY L. , JONES J. J. , LEE J. 
Published: December 2008

SUMMARY
At 4°, the activity of exogenous 8-arginine vasopressin in rat plasma decreased to 50% in 2 days, whereas there was no loss of oxytocin under the same conditions after 3 days. At 37°, oxytocin was not inactivated in 9 hr., whereas 50% of 8-arginine vasopressin was lost in 2 hr.
Forty per cent of exogenous oxytocin in rat plasma was unable to pass through a cellophane (Visking 8/32 in.) membrane, when subjected to a pressure of 100 torr for 18 hr.
In rats under pentobarbitone anaesthesia, progressive haemorrhage of more than 2·0 ml./100 g. induced a secretion of both oxytocin and 8-arginine vasopressin, to produce maximum concentrations of 450 and 700 μ-u./ml., respectively, in the carotid plasma.
In the intact rat (weighing 200–250 g.) anaesthetized with pentobarbitone, 50% of oxytocin in the circulation disappeared within 2 min. after stopping an i.v. infusion of 250–6000 μ-u./100 g./min. The half-time was increased to 4 min. by sham operation, and to 6 or 7 min. by occluding either the renal, or the portal, coeliac and mesenteric vessels. In non-lactating animals, the half-time was 8 min. after clamping both the renal and splanchnic vessels, whereas it was 6 min. in the lactating rat, under the same conditions.
The apparent volume of distribution of oxytocin was 7·3 ml./100 g. in intact rats, and 10–13 ml./100 g. after operation.
The plasma clearance of oxytocin was unaltered in the sham-operated rat, but it decreased after the operative procedures.
LUTEINIZATION OF OVARIAN GRAFTS IN RATS RELATED TO TREATMENT WITH TESTOSTERONE IN THE NEONATAL PERIOD
Authors: LADOSKY W. , NORONHA J. G. L. , GAZIRI I. F. 
Published: December 2008

SUMMARY
Male Wistar rats were castrated on the day of birth and divided into two groups; the first was injected with 0·1 mg. testosterone propionate (TP), on the day of castration and the second with 0·5 mg. TP after day 10. When 45 days old, all were grafted with an ovary in the kidney. Animals in the first group showed ovaries with ripening follicles without corpora lutea; those in the second group had corpora lutea at different stages of maturation. Ovaries grafted into female rats spayed on the day of birth developed luteinization even when injected with 0·5 mg. TP after the 10th day of life, but not if the hormone was injected earlier.
Since the hypothalamus is sensitive to androgens only before the 10th day of life even in gonadectomized rats, it can be argued that the female pattern of gonadotrophin control does not correspond to the undifferentiated hypothalamus but depends on some active central mechanism. The period during which the hypothalamus is still sensitive to androgens would correspond to the undifferentiated equipotential stage.
THE CORPUS LUTEUM OF THE SHEEP: EFFECT OF THE CONCEPTUS ON LUTEAL FUNCTION AT SEVERAL STAGES DURING PREGNANCY
Authors: MOOR R. M. , ROWSON L. E. A. , HAY MARY F. , CALDWELL B. V. 
Published: December 2008

SUMMARY
The relationship between the conceptus and the corpus luteum during the first 90 days of pregnancy was determined in sheep which were made unilaterally pregnant by egg transfer 4 or 5 days after oestrus. Additional corpora lutea were established approximately 24 hr. after an injection of human chorionic gonadotrophin given on day 20, 30, 50 or 70, and 18–24 days later the sheep were killed.
When 17 unilaterally pregnant ewes, in which new corpora lutea had been induced on or before day 31, were killed, only the corpora lutea on the same side as the gravid horn were still functional; total regression of the corpora lutea had occurred in the ovary adjacent to the non-gravid horn. In 13 out of 14 sheep in which corpora lutea had been induced on day 51 or 71, the luteal tissue was still present in both ovaries at autopsy. Thus a local effect is exerted during the first one-third of pregnancy by conceptuses confined to one uterine horn, but this effect changes to a more general one about day 50.
In five sheep, embryos were allowed to develop in an intact uterus and under these conditions no unilateral effect could be demonstrated on corpora lutea induced on day 31.
NEUROHYPOPHYSIAL FUNCTION IN AMPHIBIA: HORMONE ACTIVITY IN THE PLASMA
Authors: BENTLEY P. J. 
Published: December 2008

SUMMARY
Blood plasma of dehydrated toads (Bufo marinus) and bullfrogs (Rana catesbeiana) increased water transfer (hydro-osmotic response) across the isolated toad urinary bladder. Sodium transport (in terms of the shortcircuit current) was also increased.
Immersion of Bufo marinus, Rana catesbeiana and Xenopus laevis (but not the neotenous newt Necturus maculosus) for 2 hr. in a 2% NaCl solution also increased the hydro-osmotic activity of plasma. Ether and haemorrhage also had this effect on plasma from Rana and Bufo.
Hydro-osmotic activity of plasma from dehydrated bullfrogs was destroyed by incubation with trypsin or tyrosinase, evidence which combined with the pharmacological effects of the plasma indicate that the hydroosmotic activity in the plasma is due to arginine vasotocin. The concentrations of this hormone were comparable with levels of antidiuretic activity observed in mammalian plasma.
STUDIES ON TISSUE CULTURE OF EQUINE OVARIAN CELL TYPES: STEROIDOGENESIS
Authors: CHANNING CORNELIA P. , GRIEVES SUSAN A. 
Published: December 2008

SUMMARY
Utilizing paper and gas—liquid chromatography, the pattern of steroid secretion by cultures of equine granulosa, thecal and stromal cells has been studied.
Granulosa cell cultures secreted primarily progesterone and 20α-hydroxypregn-4-en-3-one. A granulosa cell culture of 700,000 cells harvested from two large vascular follicles of a mare in oestrus secreted the following amounts of steroid from days 0 to 6 of culture: 561 μg. progesterone, 68 μg. 20α-hydroxypregn-4-en-3-one, 5·3 μg. 17-hydroxyprogesterone, 1 μg. androstenedione, 0·12 μg. dehydroepiandrosterone and 2·7 μg. oestradiol. Thecal tissue harvested from the same follicles secreted 29, 3·0, 1·8, 1·4, 1·1 and 0·99 μg., respectively, of the same steroids. All these steroids originated from endogenous precursors or from acetate or cholesterol in the tissue culture medium which contained 15% horse serum, 30% medium '199' and 55% Hanks's solution.
Cultures of granulosa cells harvested from two large vascular follicles of a mare in early oestrus secreted progesterone at a constant rate of 35 pg./cell/day between days 6 and 34 of culture, thus demonstrating that these cells do not dedifferentiate in culture. The secretion of 20α-hydroxypregn-4-en-3-one relative to progesterone increased from days 3 to 6 and remained constant from days 6 to 15.
A MODIFIED OVARIAN CHOLESTEROL DEPLETION ASSAY FOR LUTEINIZING HORMONE
Authors: ZARROW M. X. , CLARK J. H. 
Published: December 2008

SUMMARY
The ovarian cholesterol depletion assay for luteinizing hormone (LH) was investigated in the untreated immature rat. The prepubertal rat is a satisfactory animal to use in this assay because the diurnal rhythm in ovarian cholesterol is not present until puberty. A dose-response curve was obtained between 2·5 and 10·0 μ LH and the average lambda was 0·17. The assay was specific for LH; the presence of other pituitary hormones had no significant effect on the relative potency of NIH-LH preparations. The assay is probably not sensitive enough for untreated plasma but had excellent reproducibility and is easily performed.
UPTAKE OF [14C]5-HYDROXYTRYPTAMINE BY THE UTERUS OF RATS TREATED WITH OESTROGEN AND PROGESTERONE
Authors: KOREN E. , PFEIFER Y. , SULMAN F. G. 
Published: December 2008

SUMMARY
Radioactive [14C]5-hydroxytryptamine (5-HT, serotonin) creatinine sulphate was injected intrapleurally into female rats treated with oestrogen and/or progesterone which had received, immediately before the injection of 5-HT, homogenates of placenta, foetus, uterus or plasma, taken from pregnant rats on the 19th day of pregnancy. The placental homogenate produced a significant increase in 5-HT uptake by the myometrium, when the rats had been primed with moderate doses of oestrogen plus progesterone. Higher doses prevented the increased uptake, and oestrogen treatment alone did not induce 5-HT uptake. The highest level of 5-HT accumulation in the uterus was produced by placental extract after pretreatment with 0·5 mg. oestradiol plus 10 mg. progesterone/rat/day.
These results suggest that the placenta contains a 'trans-serotonin' system which is dependent on the oestrogen—progesterone balance and serves to accumulate 5-HT in the placenta and myometrium. Shifts of the hormonal balance may contribute to the release of 5-HT and thus promote uterine contractions at any stage of pregnancy.
THE RELATIVE POTENCIES OF OESTRIOL, OESTRADIOL AND OESTRONE ON THE UTERUS AND VAGINA OF THE MOUSE
Authors: MILLER B. G. 
Published: December 2008

SUMMARY
The effects of oestriol, oestradiol and oestrone on the uterus and vagina of the mouse have been investigated, by measuring changes in the incorporation of tritiated uridine into RNA, and in wet and dry organ weight. The time course of the uridine response to a single injection of oestriol differs markedly from that seen with single injections of oestradiol and oestrone. Oestriol has only a weak uterotrophic action in tests employing daily oestrogen injections, but when administered every 4 hr. in small doses it elicits as much growth in both organs as does oestradiol. The relative capacities of oestriol and oestradiol to sensitize the uterus to the induction of deciduomata by peanut oil are contrasted.
A SENSITIVE IN-VITRO METHOD FOR THE ASSAY OF CHOLECYSTOKININ
Authors: AMER M. S. , BECVAR W. E. 
Published: December 2008

SUMMARY
A sensitive assay method for cholecystokinin is described utilizing strips of rabbit gall bladder. The preparation is not responsive to secretin, histamine, or ammonium salts. The assay is more reproducible, sensitive and specific than other in-vitro methods.
THE SITES OF IODINE ACCUMULATION AND THE IODOAMINO ACIDS IN THE THYROID AND PLASMA OF PLAICE (PLEURONECTES PLATESSA L.)
Authors: OSBORN R. H. , SIMPSON T. H. 
Published: December 2008

SUMMARY
Whole body scanning and radioautography of plaice injected with 125I failed to show extra-pharyngeal sites of thyroid activity. The constituent iodoamino acids of thyroid tissue and of blood plasma have been identified by thin-layer chromatography of the parent compounds and of their derivatives, the preparation of which is described. Thyroid tissue has been found to contain 3,5,3′-tri-iodothyronine (T3), thyroxine (T4), 3-iodotyrosine (MIT) and 3,5-di-iodotyrosine (DIT). T3 and T4 were the only iodoamino acids detected in plasma.
GAS—LIQUID CHROMATOGRAPHY FOR ESTIMATION OF PERIPHERAL PLASMA PROGESTERONE IN DOMESTIC ANIMALS
Authors: STABENFELDT G. H. , EWING L. L. , PATTON J. P. , McDONALD L. E. 
Published: December 2008

SUMMARY
A method was adapted for the quantitative determination of progesterone obtained from the peripheral plasma of several domestic animals (cow, gilt and ewe). The technique utilized the detection of a chloroacetate derivative of 20β-hydroxypregn-4-en-3-one (enzymically converted from progesterone) by gas—liquid chromatography with electron capture detection. An improved extraction procedure is presented in which the plasma extract is saponified instead of the plasma; this was particularly effective for the removal of the yellow pigments normally found in large amounts in bovine plasma and allowed one-step isolation of progesterone by thin-layer chromatography. Progesterone levels in the peripheral plasma during the follicular phase of the oestrous cycle of the cow, gilt and ewe averaged 0·4 ng./ml., 0·5 ng./ml. and 0·2 ng./ml., respectively. Luteal phase levels of progesterone averaged 6·6 ng./ml., 27·1 ng./ml. and 2·1 ng./ml. in the cow, gilt and ewe, respectively. Progesterone increased during gestation in one cow from 4·7 (sixth month) to 6·1 ng./ml. plasma (eighth month). No evidence was obtained for a pre-ovulatory rise of progesterone in one cow during the 12 hr. immediately following oestrus.
It is suggested that corpus luteum function can be monitored in domestic animals during the oestrous cycle by the daily estimation of progesterone in the peripheral plasma.
THE EFFECT OF OESTRADIOL-17β ON ENZYMES CONCERNED WITH METABOLISM OF CARBOHYDRATE IN HUMAN ENDOMETRIUM IN VITRO
Authors: WILSON E. W. 
Published: December 2008

SUMMARY
Human endometrium in the regenerative phase was maintained for 5 hr. in vitro with oestradiol-17β alone or together with actinomycin D. Qualitative and quantitative histochemistry of the tissue showed that the activities of glucose-6-phosphate, 6-phosphogluconate, and lactate dehydrogenases were increased by oestradiol, and that actinomycin suppressed the hormonal effect. The activities of succinate and iso-citrate dehydrogenases were unaffected by oestradiol. An attempt is made to correlate the metabolic roles of the enzymes affected by oestradiol. The suppression, by actinomycin, of the oestradiol effect suggests that the increased enzyme activity is due to the formation of new enzyme protein.
STUDIES ON THE ENZYMIC FORMATION OF DI-IODOTYROSINE BY A MICROSOMAL PREPARATION OF GOAT SUBMAXILLARY GLAND
Authors: HATI RATHA N. , DATTA ASOKE G. 
Published: December 2008

SUMMARY
Subcellular fractions of goat submaxillary gland catalysed the iodination of monoiodotyrosine to form di-iodotyrosine; the microsomal fraction was found to have maximum activity. The enzyme needed copper or hydrogen peroxide for its activity. Thiourea and thiouracil inhibited the enzymic activity. Manganese and ferric ions inhibited the enzymic formation of di-iodotyrosine. The enzyme was solubilized by sodium desoxycholate treatment.
INDUCTION OF IMPLANTATION OF BLASTOCYSTS TRANSFERRED TO OVARIECTOMIZED MICE
Authors: HUMPHREY K. W. 
Published: December 2008

SUMMARY
Blastocysts transferred to progesterone-treated ovariectomized mice implanted only if oestradiol was given at or after transfer. A dose of 1·0 m.g. Provera/day maintained the implants to term. Omission of priming with oestradiol did not prevent implantation. Transfers performed on day 0, 1 or 2 of progesterone treatment were completely unsuccessful, while transfers on day 8 were less effective than those performed on day 3 or 4. Administration of oestradiol 24 or 48 hr. beforehand did not prevent the induction of implantation by a second dose of oestradiol, and did not render the uterus 'refractory'. Treatment with 8 ng. oestradiol on days 1 to 5 or day 4 or 5 induced implantation of blastocysts transferred on day 4.
It is concluded that oestrogen is not released as a surge before implantation, but is released continuously after ovulation.
SEX DIFFERENCE IN THE RELEASE OF LUTEINIZING HORMONE EVOKED BY PROGESTERONE
Authors: TALEISNIK S. , CALIGARIS L. , ASTRADA J. J. 
Published: December 2008

SUMMARY
Long-term gonadectomized female and male rats showed increased plasma luteinizing hormone (LH) activity (as measured by the ovarian ascorbic acid depletion method). A single injection of 20 μg. oestradiol benzoate or 2·5 mg. testosterone propionate after 3 days reduced the raised values significantly. Progesterone injected into gonadectomized rats primed with gonadal steroids exerts a positive feed-back action on the release of LH. In ovariectomized rats the injection of progesterone 3 days after a single injection of oestradiol or testosterone induced, a few hours later, a significant increase in plasma LH. In contrast, castrated male rats responded to progesterone with an increase in plasma LH only when they had been primed 3 days before with testosterone. This difference was not eliminated by gonadectomy on the first day of life. Androgen-sterilized ovariectomized rats failed to show an increase in plasma LH after progesterone when primed with testosterone but did so after priming with oestradiol. In male rats treated with testosterone in the early neonatal period, the normal LH release induced by progesterone in testosterone-primed animals was abolished. It is concluded that separate female and male patterns of LH release evoked by progesterone exist in the rat, and the difference between them is not determined by a postnatal differentiation in the neural mechanism which controls the secretion of LH.
THE BINDING OF [1,2-3H]TESTOSTERONE WITHIN NUCLEI OF THE RAT PROSTATE
Authors: MAINWARING W. I. P. 
Published: December 2008

SUMMARY
The specificity of the binding of [1,2-3H]testosterone to nuclei of various rat tissues in vivo has been studied. A significant amount of radioactivity was retained in the nuclei of androgen-dependent tissues only, particularly the ventral prostate gland. The bound radioactivity was only partially recovered as [1,2-3H]testosterone; the remainder was identified as [3H]5α-dihydrotestosterone. Efforts were made to characterize the binding component, or 'receptor', in prostatic nuclei. On digestion of nuclei labelled in vivo with [1,2-3H]testosterone, with enzymes of narrow substrate specificity, only trypsin released tritium, suggesting that the receptor is a protein. On the basis of subfractionation studies of labelled nuclei, the receptor is an acidic protein. The androgen—receptor complex could be effectively extracted from the prostatic nuclei in 1 m-NaCl and from the results of fractionations on a calibrated agarose column, the complex has a molecular weight 100,000–120,000. The specificity of the binding of steroids to such 1 m-NaCl extracts in vitro was investigated by the equilibrium dialysis procedure. Under these conditions, the specificity of the binding of [1,2-3H]testosterone demonstrated in vivo could not be simulated. The receptor is probably part of the chromatin complex but its precise intranuclear localization cannot be determined by biochemical procedures alone.
FOLLICLE-STIMULATING HORMONE CONTENT OF THE PITUITARY GLAND BEFORE IMPLANTATION IN THE MOUSE AND RAT
Authors: BINDON B. M. 
Published: December 2008

SUMMARY
The method of Lamond & Bindon (1966) was used to measure follicle-stimulating hormone (FSH) in the pituitary glands of mice and rats killed at different times on each of days 1–6 of pregnancy. The sensitivity of the method allowed detection of FSH fluctuations not previously described in these species.
A significant fall in pituitary FSH occurred in both species on day 3, although it was earlier in the mouse than in the rat. This transient decline in FSH activity, interpreted as a release of the hormone, was followed in both species by a gradual increase on days 4 and 5. Ovarian weight, measured only in the mouse, increased significantly late on day 3 and is believed to reflect changes in pituitary FSH.
The results indicate that implantation in the mouse and rat is initiated by altered activity of the pituitary gland during the first 3 days of pregnancy. It appears that this pituitary mechanism differs from that responsible for the events of the oestrous cycle.