bluuebunny/crossref_metadata_2025_split huggingface dataset:
T4 AND T3 RELEASE FROM THE PERFUSED CANINE THYROID ISOLATED IN SITU
Authors: Laurberg Peter 
Published: December 2008

ABSTRACT
A method for once-through perfusion of the canine thyroid isolated in situ is described. The perfusion medium was a modified Krebs Ringer buffer with 4 % dextran added. In 4 control experiments the T4 and T3 concentrations in effluent were stable or slightly falling during 3 h perfusion. There were no significant alterations in the T4/T3 ratio in the effluent during these experiments.
A 10-min infusion of bovine TSH (1 mU/ml) caused an increase in the release of T4 and T3 after 15–25 min. The T4/T3 ratio in the effluent was significantly reduced after TSH stimulation. However, the ratio returned to pre-stimulation values while the hormone release was still very high. T4 and T3 content of the contralateral thyroid was determined after homogenation and hydrolysis with pronase. The T4/T3 ratio in the homogenate was twice as high as the T4/T3 ratio in the effluent during control perfusion. Thus there was a preferential secretion of T3 from the perfused canine thyroid and this was increased after TSH stimulation.
ENHANCEMENT OF GLUCOSE-STIMULATED INSULIN SECRETION FROM ISOLATED RAT PANCREATIC ISLETS BY HUMAN INSULIN ANTIBODIES
Authors: Hahn H. J. , Menzel R. , Gottschling H. D. , Jahr D. 
Published: December 2008

ABSTRACT
Isolated pancreatic rat islets incubated in vitro were used as a bioassay system for investigating the influence of human insulin antibodies on insulin secretion. Serum samples with different titres of insulin antibodies were obtained from juvenile diabetics after various periods of insulin therapy. The insulin secretion of isolated islets is enhanced by insulin antibodies and positively correlated to the measured antibody titres in serum.
EFFECTS OF ANDROSTENES, 5α-ANDROSTANES, 5β-ANDROSTANES, OESTRENES AND OESTRATRIENES ON SERUM GONADOTROPHIN LEVELS AND VENTRAL PROSTATE WEIGHTS IN GONADECTOMIZED, ADULT MALE RATS
Authors: Verjans H. L. , Eik-Nes K. B. 
Published: December 2008

ABSTRACT
The effects of subcutaneous administration of steroids from the androstene, 5α-androstane, 5β-androstane, oestrene and oestratriene series on serum levels of LH and FSH and on ventral prostate weights were investigated in gonadectomized, adult male rats. Each steroid was administered for seven days in a standard dose of 100 μg per 100 g body weight per day. 5α-Androstanes disubstituted with oxygen in the positions 3 (3-keto or 3α-hydroxy) and 17 (17-keto or 17β-hydroxy) were effective in suppressing either one or both serum gonadotrophins. 5β-Androstanes and androstenes exhibited very little inhibitory effect in this respect. Potent suppression of serum gonadotrophins was observed following treatment with oestratrienes, the presence of only a phenolic A-ring in these oestrogens appeared sufficient for such suppression. 3 or 3β and 17 or 17β disubstituted (keto or hydroxyl) androstenes could entirely or partly prevent ventral prostate weight decrease post-gonadectomy. 5α-Androstane-3α,17β-diol, 5α-androstane-3α,11β,17β-triol and 5α-androstan-17β-ol-3-one were most potent, while 5β-androstanes and oestratrienes had no effect on this decrement. Regulatory processes by steroids at the hypothalamic-pituitary and at the ventral prostate level were not parallel.
The results indicate, however, that 3 or 3α and 17 disubstituted (keto or hydroxyl) 5α-reduced testosterone metabolites, of which 5α-androstan-17β-ol-3-one might be the principal one, are the main steroids directing androgenic regulation at both organ systems tested in the mature male rat.
FACTORS GOVERNING THE STIMULATION OF EMBRYONIC CHICK CARTILAGE BY SOMATOMEDIN
Authors: Herington A. C , Phillips L. S. , Daughaday W. H. 
Published: December 2008

ABSTRACT
In these studies of the stimulation of embryonic chick pelvic rudiments by somatomedin (Sm) in serum, we have found that cartilage weight and duration of cartilage exposure to serum determine the stimulation of cartilage by serum and the relative stimulation by Sm and by other non-Sm serum components, respectively. These factors are critical for the use of this system to measure Sm in serum.
Initial experiments revealed that incorporation of sulfate (SO4) by cartilage incubated in buffer fell rapidly after 9 h and reached very low levels by 30 h. Incubation in 40 % normal human serum (NHS) produced significant stimulation of incorporation of SO4 after 4 h, and maintained at least initial levels of incorporation for 24 h. The greatest % stimulation by NHS over buffer was seen with prolonged incubation (44 h). However, specificity for Sm (discrimination between NHS and hypophysectomized human serum (HHS)) was greater with shorter incubation times. The potency of HHS was 11, 42 and 92 % of the potency of NHS following early, intermediate and late measurement of incorporation of SO4 by cartilage, respectively. The best overall results were obtained with intermediate incubation time and measurement of SO4 incorporation ((35S)-SO4 present for the final 5 h of a 25 h incubation), which allowed good precision (λ = 0.17) while maintaining satisfactory specificity for Sm. Since prolonged incubation with late measurement of SO4 incorporation allowed the greatest % stimulation by serum with little differentiation between NHS and HHS, stimulation of incorporation of SO4 under these conditions is apparently due to non-Sm factors present in both NHS and HHS.
In addition to incubation time, cartilage stimulation by serum was also determined by cartilage weight. Lighter cartilage (from younger embryos) was associated with higher unstimulated incorporation of SO4 (P < 0.01), lower stimulation by added serum (P < 0.01), and inadequate assay precision (P < 0.05): satisfactory assays were generally obtained with cartilage rudiments weighing more than 0.7 mg (dry weight).
CIRCADIAN FLUCTUATIONS OF SERUM HORMONE LEVELS IN PREPUBERTAL MALE AND FEMALE RATS
Authors: Döhler K. D. , Wuttke W. 
Published: December 2008

ABSTRACT
Diurnal variations in serum hormone levels during 2 different stages of prepubertal development were investigated in male and female rats. Groups of 13 to 18 and 25 to 30 day old male and female rats were decapitated at 4-hour by intervals during a period of 24 h. Their blood was collected and hormones were measured by radio-immunoassay.
FSH levels were constantly high in 13 to 18, but low in 25 to 30 day old females. FSH was low in younger males, and significantly higher but without diurnal fluctuations in the older males. Serum LH was low in approximately 40% of the 13 to 18 day old females, while 40% had moderately high levels, and the remaining females extremely high levels of the hormone. Most of the extremely high LH peaks were found at 15.00 h and some at 03.00 h. Older females and males of both age groups had constantly low serum LH levels. Serum oestradiol was high in males and females during days 13 to 18, but it was lower in the 25 to 30 day old animals. In the young females prolactin was slightly elevated between 15.00 h and 19.00 h, while in the males the serum prolactin fluctuations were not significant. Serum testosterone was low in females at all times. The 13 to 18 day old males had higher testosterone levels than the 25 to 30 day old males. Both groups showed slight, but insignificant fluctuations in serum testosterone.
These results confirm result published previously and furthermore they demonstrate the existence of circasemedian or circadian rhythms for both the gonadotrophins and gonadal steroids. These results, also suggest that the maturation of the positive feedback action of oestradiol on gonadotrophin release in female rats occurs between day 10 and 20.
THE LIVER AS A SOURCE OF SOMATOMEDIN
Authors: Schimpff R. M. , Donnadieu M. , Glasinovic J. C. , Warnet J. M. , Girard F. 
Published: December 2008

ABSTRACT
Somatomedin (Sm) activity (measured by [35S] uptake in chick embryo cartilage) was determined in serum samples simultaneously drawn from the hepatic vein, portal vein, femoral artery and femoral vein of seventeen anaesthezied normal adult dogs). A pool of human serum was taken as reference (Sm = 1 U/ml).
Sm levels in the peripheral vein of dogs were 0.38 ± 0.03 U/ml). Mean ± sem).
Sm activity was greater in the hepatic vein (0.48 U/ml) than in the other vessels (0.36, 0.39, 0.38 U/ml), and the paired differences were significant (P<0.02 to P<0.05).
In three dogs which received b-GH (20 IU/day), the Sm levels were significantly increased after nine days in the femoral vein (P < 0.05) and in the hepatic vein (P < 0.05).
The validity of the assay is discussed; a possible interference of NEFA in the assay is eliminated.
The difference of Sm levels between hepatic and portal veins, related to hepatic flow measured in seven of these dogs, indicate an important production of Sm by the liver.
THE INFLUENCE OF NORETHISTERONE OENANTHATE ON OVARIAN FUNCTION
Authors: Weiner Erik , Johansson Elof D. B. 
Published: December 2008

ABSTRACT
Two-hundred mg norethisterone oenanthate was injected im into five women on the fifth or sixth day after the onset of the menstrual bleeding. The plasma levels of oestradiol and progesterone were measured during one control cycle before the injection and then for three months or until ovulation occurred.
According to the plasma progesterone pattern the five women ovulated during the control cycle. After the injection ovulation was delayed in all the subjects. In two of the participants the first ovulation occurred around 55 days after the injection, while in two others ovulation was delayed about 80 days. The fifth woman did not ovulate until 16 weeks after the injection.
The treatment did not suppress the plasma levels of oestradiol below the levels seen in untreated women during the follicular phase.
It is concluded that the treatment with 200 mg of norethisterone oenanthate im can inhibit ovulation for an unpredictable time, but that the ovulatory pattern is restored within 12 weeks in most of the women.
BINDING OF TRITIATED METHYLATED LUTEINIZING HORMONE TO BOVINE CORPUS LUTEUM RECEPTORS
Authors: de la Llosa-Hermier M. Paloma , Hermier Claude , de la Llosa Pedro 
Published: December 2008

ABSTRACT
The binding of luteinizing hormone (LH) to cow corpora lutea homogenates was studied using a tritium labelled hormone obtained by reductive methylation. The KD observed was 0.9 10−10 m and the number of sites was the equivalent of 0.4 10−15 moles per mg of wet tissue. The influence of the pH and temperature was examined. HCG and LH produced the same binding inhibition curves as did unlabelled methylated LH, suggesting that the binding properties of the derivative used for labelling LH were similar to those of native LH. The inhibitory activity of the subunits was extremely low (α-LH: 4%, β-LH: 1%). No significant inhibition was observed in the case of FSH or prolactin.
THE SOURCE OF OVARIAN OESTRADIOL AND ANDROSTENEDIONE IN THE SHEEP DURING THE LUTEAL PHASE
Authors: Baird D. T. , Scaramuzzi R. J. 
Published: December 2008

ABSTRACT
The secretion of oestradiol and androstenedione was investigated in sheep by cannulating both ovarian veins in situ. The mean ovarian blood flow (ml/min ± se) was significantly higher on the side containing the corpus luteum (7.67 ± 1.36) than on the contralateral side (4.93 ± 0.85). The mean secretion (ng/min ± se) of oestradiol (1.09 ± 0.36) and androstenedione (1.52 ± 0.16) was higher on the side containing at least one large follicle (diameter > 4 mm) than on the contralateral side (0.19 ± 0.05 and 0.62 ± 0.21, respectively). The secretion of oestradiol was unchanged following enucleation of the corpus luteum but fell to very low levels (0.062 ± 0.022 ng/min) after enucleation of follicles diameter > 4 mm. The secretion of androstenedione fell significantly after enucleation of both corpus luteum and large follicles. These results suggest that during the luteal phase in the sheep oestradiol is secreted virtually exclusively by the largest non-atretic Graafian follicle. Androstenedione in contrast arises from both follicle, corpus luteum and possibly stroma.
THE PRIMARY EMPTY SELLA AN ENDOCRINE STUDY ON 12 CASES
Authors: Schaison G. , Metzger J. 
Published: December 2008

ABSTRACT
Twelve patients (10 women and 2 men) with a primary empty sella turcica were studied. Endocrine function tests were performed as follows: growth hormone (GH) was measured after insulin-induced-hypoglycaemia, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) after LH-releasing hormone, thyrotrophin (TSH) and prolactin after thyrotrophin-releasing hormone; pituitary reserve of adrenocorticotrophin (ACTH) was determined by measurement of plasma cortisol after lysinevasopressin and 11 deoxycortisol after metyrapone.
Five of the patients (group A) had no endocrine disturbance.
Seven patients (group B) had a hypothalamo-pituitary disorder. Two of them had panhypopituitarism which appeared in one case after meningoencephalitis and in the other after a severe cranial trauma. In two cases an amenorrhoea-galactorrhoea syndrome with increased prolactin level (68 and 230 ng/ml) led to a diagnosis of a prolactin producing adenoma, which was confirmed by surgery. Finally three cases of amenorrhoeagalactorrhoea, with normal prolactin level, and/or diabetes insipidus remained unexplained. However, no causal relationship could be demonstrated between the pituitary disturbance and the "empty sella".
Primary empty sella turcica is therefore a neuroanatomical and neuroradiological entity with no endocrine implication. A pituitary disorder might suggest a microadenoma or an incidentally associated disease.
SERUM LH AND FSH LEVELS FOLLOWING INTRAVENOUS INJECTION OF A GONADOTROPHIN RELEASING PRINCIPLE IN NORMAL AND GONADECTOMIZED ADULT MALE RATS TREATED WITH OESTRADIOL-17β OR 5α-DIHYDROTESTOSTERONE
Authors: Verjans H. L. , Eik-Nes K. B. 
Published: December 2008

ABSTRACT
Effect of intravenous administration of a synthetic gonadotrophin releasing factor (GnRF) on circulating LH and FSH concentrations was investigated in normal and gonadectomized, adult male rats injected subcutaneously each day during seven days with various doses of oestradiol-17β or 5α-dihydrotestosterone in sesame oil. Higher increase in serum LH and FSH levels subsequent to intravenously administered GnRF was observed in castrated control animals than in intact control animals, though this increment was not of significant nature for serum FSH. Pre-treatment of normal and gonadectomized rats with oestradiol-17β resulted in an augmented response of serum LH and FSH concentrations to GnRF iv. Pre-treatment of normal and gonadectomized rats with 5α-dihydrotestosterone diminished serum LH and FSH response following administration of the same amount of GnRF. For these steroids to affect the response pattern of serum LH and FSH to GnRF iv, higher doses were required in normal than in gonadectomized animals. The data indicate that oestrogen and androgen may act at different sites in the male hypothalamic-pituitary axis with respect to regulation of pituitary gonadotrophins.
PREGNANT MARE'S SERUM GONADOTROPHIN. I.
Authors: Pal Alok K. , Gupta Tarun , Chatterjee Amar 
Published: December 2008

ABSTRACT
A single consistent Iuteolytic dose of 10 IU PMSG given on day 5 of pregnancy caused complete resorption of foetuses and placentae associated with a polyfollicular ovarian state in rats. Concomitant treatment with progesterone or prolactin given concurrently with PMSG was found to overcome the antifertility efficacy of PMSG and maintained the endocrine balance favouring pregnancy maintenance. It was postulated that the PMSG-induced ovarian polyfolliculogenesis might be responsible for luteolysis of the corpus luteum gravidarum.
EFFECT OF COLD-EXPOSURE ON SERUM THYROTROPHIN LEVELS IN MAN
Authors: Tuomisto J. , Männistö P. , Lamberg B.-A. , Linnoila M. 
Published: December 2008

ABSTRACT
Serum TSH levels were measured after exposing male volunteers to cold, or successively to warmth and to cold, causing clear changes in body temperature. Very moderately heated Finnish sauna bath increased body temperature to about an average of 39°C, and cooling in a relatively warm swimming pool (+25 to +28°C, 30 min) decreased body temperature to below 35°C after sauna, and to about 33°C without sauna. In both cases a slight but significant initial increase of serum TSH was demonstrated. No changes in serum T3 or ETR were seen. The results suggest that a similar mechanism of initial TSH response may exist in humans as has previously been demonstrated in rats.
METABOLISM OF PROGESTERONE IN UTERINE TISSUE OF NON-PREGNANT RATS IN VITRO
Authors: Lisboa B. P. , Holtermann M. 
Published: December 2008

ABSTRACT
The metabolism of labelled progesterone was studied in vitro in uterine tissue of non-pregnant rats with particular emphasis on the influence of substrate concentration. Neither a qualitative nor quantitative difference was found for a steroid tissue ratio between 15 × 10−6 and 4.2 × 10−9 to 1 g (substrate amounts between 57.73 and 0.02 nmol); with both concentrations 42 to 44 per cent of progesterone was metabolized to about 35 per cent monohydroxymonoketonic steroids and 4–6 per cent dihydroxylated C21O2-compounds.
In both sets of incubations we have isolated and identified the following steroids: 3α-hydroxy-5α-pregnan-20-one, 3β-hydroxy-4-pregnen-20-one, 3α-hydroxy-4-pregnen-20-one, 20α-hydroxy-4-pregnen-3-one, 5α-pregnane-3α,20α-diol and 4-pregnene-3α,20α-diol. The most abundant metabolite formed in these incubations was 3α-hydroxy-4-pregnen-20-one -which corresponds to about 30 per cent of the total activity recovered. It is the first time that the presence of 20α-hydroxysteroid-oxidoreductase activity is definitely established in this type of tissue.
The identification of three allylic alcohols as progesterone metabolites in the rat uterus confirms that Δ4-3-hydroxysteroids are important intermediates in the in vitro uterine metabolism of steroids.
CORTISOL EFFECT ON COLLAGEN BIOSYNTHESIS IN EMBRYONIC EXPLANTS AND IN VITRO HYDROXYLATION OF PROTOCOLLAGEN
Authors: Blumenkrantz Nelly , Asboe-Hansen Gustav 
Published: December 2008

ABSTRACT
The effect of increasing doses of hydrocortisone acetate, hydrocortisone phosphoric acid complex, and hydrocortisone sodium succinate on collagen biosynthesis was assayed in two different systems.
I. Explants of chicken embryo tibiae showed decreased biosynthesis of [14C]hydroxyproline and total and glycosylated [14C]hydroxylysine under the influence of high doses of hydrocortisone. With the lower doses of hydrocortisone acetate, no effect was noticed. The total uptake of the precursor amino acids followed patterns similar to those of collagen biosynthesis.
II. Hydroxylation of [14C]proline labelled protocollagen by protocollagen proline hydroxylase was inhibited by high doses of hydrocortisone acetate, hydrocortisone phosphoric acid complex, and hydrocortisone sodium succinate.
III. A decreased diffusion of collagen to the medium with increasing doses of hydrocortisone acetate, hydrocortisone phosphoric acid, and hydrocortisone sodium succinate was noticed.
IV. No further hydroxylation of new-synthesized collagen was obtained under the influence of hydrocortisone phosphoric acid and hydrocortisone sodium succinate, when the undialyzable material was used as a substrate for protocollagen proline hydroxylase.
EFFECTS OF SMALL DOSES OF L-THYROXINE AND TRIIODO-L-THYRONINE ON PITUITARY LH CONTENT OF THYROIDECTOMIZED RATS
Authors: Aranda A. , Hervás F. , de Escobar G. Morreale , del Rey F. Escobar 
Published: December 2008

ABSTRACT
Pituitary LH was studied by means of a specific radioimmunoassay (RIA) in male rats at different time intervals after thyroidectomy (T̄), and in rats which were T̄ at least 30 days before and were then treated with different doses of L-thyroxine or triiodo-L-thyronine.
A decrease in the pituitary LH of the T̄ animals, with respect to the intact age-paired controls, was demonstrable from 13 days after the operation, when total pituitary LH content was taken into consideration, or from 5 days after T̄, when the LH concentration (μg/mg pituitary) was considered. Doses of thyroid hormones lower than the daily maintenance dose for the rat produced very little effect on the pituitary LH levels of T̄ animals. However, a single dose of 1.75 μg of T4 or 0.2 μg of T3 (doses approximately equivalent to the T4 and T3 maintenance dose for T̄ rats) induced such a rapid and intense increase in the pituitary LH content that it no longer differed from that of the intact age-paired controls by 12 hours. Surprisingly, 5.0 μg of T4 and 1.0 μg of T3 did not produce any increase in the pituitary LH content of T̄ rats.
STUDIES IN CONGENITAL GENERALIZED LIPODYSTROPHY
Authors: Oseid Svein , Pruett Esther D. R. 
Published: December 2008

ABSTRACT
Two patients with congenital generalized lipodystrophy have been studied at rest, and during and after long-term exercise at different carefully measured work loads. The two patients represented different stages of diabetes development.
Both patients derived most of their energy used during muscular exercise from carbohydrate, and comparatively little from fat. FFA levels remained low throughout the period of observation in contrast to normal individuals and patients with juvenile diabetes. The data presented seem to show that deposition of glucose and free fatty acids (FFA) as triglyceride, must be impaired and are not compatible with the concept of increased triglyceride turnover in the adipocytes.
The fall in blood glucose concentration (BCG) was less than in normal individuals and juvenile diabetics during exercise, and the glucose tolerance remained unchanged following work stop in both patients (k-values unchanged), in contrast to normal persons and patients with juvenile diabetes.
Both patients showed significant falls in circulating immuno-reactive insulin (IRI) levels during exercise irrespective of a rise or fall in BGC. Thus, the exercise itself might activate endogenous mechanisms which could, on the one hand increase the circulating BGC, and at the same time force circulating IRI to decrease, thus disturbing the well-known relationship between circulating glucose and IRI levels as has been exhibited in normal subjects. The high IRI levels, also during exercise in these patients, indicate a' relative insulin resistance in the muscles, but less marked than the insulin resistance in the adipose tissue.
The IRI response after glucose infusion did not change significantly with increasing work loads with one exception.
Exercise did not alter significantly the human growth hormone (HGH) levels in either the diabetic or the non-diabetic patient indicating an abnormal regulation of the HGH secretion in congenital lipodystrophy.
DEMONSTRATION OF CORTICOTROPHIN-RELEASING ACTIVITY IN RAT AND HUMAN PERIPHERAL BLOOD
Authors: Yasuda Naoki , Greer Monte A. 
Published: December 2008

ABSTRACT
Corticotrophin-releasing activity of rat or human peripheral blood was examined with a sensitive in vitro CRF bioassay, using cultured rat adenohypophyseal cells and ACTH measurement by radioimmunoassay. A dose-related ACTH secretion into the medium occurred in response to plasma or serum obtained from unstressed rats or humans. The minimum effective dose was 2.5 μl (0.1% of the medium concentration). No concomitant release of TSH occurred, indicating that cellular destruction was not the source of ACTH in the medium. As previously found with hypothalamic extract, 50% of the maximum ACTH secretion produced by a given quantity of plasma occurred within 1–5 min. Fifty per cent of CRF activity was retained after plasma was boiled for 5 min. CRF activity of serum was not different in intact, 1–10 min. ether-stressed, adrenalectomized, hypophysectomized or dexamethasone-treated rats. There was no significant difference in CRF activity between serum from intact rats and those with complete forebrain removal and hypophysectomy, indicating that serum CRF originates from a source outside the forebrain or pituitary. Because of the lack of correlation of blood CRF activity with conditions in which there are marked differences in in vivo ACTH concentration, it is possible that the blood CRF activity we measure is non-specific.