bluuebunny/crossref_metadata_2025_split huggingface dataset:
PROSTAGLANDIN MEDIATED NATRIURESIS DURING GLUCAGON INFUSION IN DOGS
Authors: Olsen Uffe Bang 
Published: December 2008

ABSTRACT
Ten μg/min glucagon infused intravenously for 30 min in conscious dogs (weight 15–25 kg) is shown to increase renal prostaglandin activity and to produce a natriuretic effect, which is impaired by indomethacin pretreatment. Cardiac output, heart rate, renal blood flow and urine cAMP excretion are similarly increased in non-pre-treated and indomethacin pre-treated dogs. Glucagon infusion does not consistently change plasma renin activity in non-pre-treated dogs, while the renin secretion is almost totally blocked when glucagon is administered to dogs that are pre-treated with indomethacin.
The results are consistent with the view that the natriuretic response to glucagon is largely dependent upon increased renal blood flow. An addition tubular prostaglandin mediated and possible anti-aldosterone effect is, however, also involved.
THE SIZE OF GROWTH HORMONE GRANULES IN PITUITARY ADENOMAS PRODUCING ACROMEGALY
Authors: Landolt Alex M. , Rothenbühler Verena 
Published: December 2008

ABSTRACT
Measurements of the diameters of large numbers of granules in electron micrographs of pituitary adenomas in cases of acromegaly do not show that a typical size exists which allows of the retrospective diagnosis of the hormone secreted by the tumour. The granule diameters found in single cases show a normal distribution. The average values determined in 19 unselected cases of acromegaly range between 160 and 342 nm. They are also normally distributed about the mean for the entire group which is 238 nm. With histo-immunological electron microscopic techniques hGH can be demonstrated in small, medium and large granules. The size of hormone granules is determined by functional factors such as the speed of hormone synthesis and hormone release but not by the type of hormone secreted.
ALTERED RESPONSIVENESS TO HYPOPHYSIOTROPHIC HORMONES OF PERIFUSED RAT PITUITARY TUMOURS
Authors: Carlson Harold E. , Mariz Ida K. , Briggs Jacqueline E. , Daughaday William H. 
Published: December 2008

ABSTRACT
Since growth hormone (GH) and prolactin (Prl) secretion by human pituitary tumours is often influenced by the hypophysiotrophic hormones thyrotrophin-releasing hormone (TRH) and somatostatin (SRIF), we have examined the responses of several transplantable rat pituitary tumours to these substances in a perifusion apparatus. The MStT/W15 tumour did not alter its secretion of GH and Prl in response to TRH, SRIF, or a partially purified porcine hypothalamic extract containing GH-releasing activity; normal rat pituitaries show clear responses to each of these substances. Theophylline and dibutyryl cyclic AMP each provoked increased GH and Prl release from the tumour. A second specimen of the MStT/W15 tumour and a specimen of the MStT/W5 tumour behaved in a manner identical to the original MStT/W15, showing no response to TRH or SRIF, but releasing both GH and Prl when theophylline or dibutyryl cyclic AMP was given. The MtT/F4 tumour increased its secretion of GH in response to TRH, 10 μg/ml, and theophylline, but no effect was seen with lower concentrations of TRH or with SRIF; Prl secretion by the F4 tumour was increased by theophylline, but TRH and SRIF had no effect. The autonomy demonstrated in these experimental tumours may be due to a loss of specific hypophysiotrophic hormone receptors or of secretory activating mechanisms.
DIURNAL RHYTHM OF VASOTOCIN IN THE PINEAL OF THE MALE RAT
Authors: Calb Maria , Goldstein R. , Pavel S. 
Published: December 2008

ABSTRACT
The pineal content of arginine vasotocin in the male rat is subject to diurnal changes, having a high value around noon and a low value around midnight. Since in rats exposed to 24 h constant light the pineal content in arginine vasotocin decreases, and in the rats exposed to 24 h constant darkness the pineal content in arginine vasotocin increases, it appears that during the night both the synthesis and release of arginine vasotocin is enhanced.
FIVE CASES OF ABSENCE OF IODIDE CONCENTRATING MECHANISM
Authors: Toyoshima K. , Matsumoto Y. , Nishida M. , Yabuuchi H. 
Published: December 2008

ABSTRACT
Five cases, 2 males and 3 females, with absence of iodide concentrating mechanism are reported. Three of the five subjects are siblings and the eldest sister has no symptom to account for the cretinism. All 5 cases have improved clinically following the administration of potassium iodide and 4 cases are still in a euthyroid state without any adverse effects during a half to more than 4 years. This study suggests that the absence of iodide concentrating mechanism might be erroneously diagnosed as athyroidal cretinism or adolescent non-toxic diffuse goitre, and may at times not show any clinical symptoms.
THE INTERRELATIONSHIPS BETWEEN SERUM 25-HYDROXYCHOLECALCIFEROL, SERUM PARATHYROID HORMONE AND BONE CHANGES IN ANTICONVULSANT OSTEOMALACIA
Authors: Mosekilde Leif , Christensen Merete Sanvig , Lund Birger , Sorensen Ole Helmer , Melsen Flemming 
Published: December 2008

ABSTRACT
Serum 25-hydroxycholecalciferol (25-HCC) and serum parathyroid hormone (iPTH) were measured in 59 randomly selected adult epileptic outpatients receiving chronic anticonvulsant therapy. Quantitative morphometric analysis of iliac crest biopsies was performed. A mild degree of osteomalacia was found which was inversely correlated to dietary vitamin D intake. Serum 25-HCC was reduced in the epileptic patients compared to a control group, although dietary intake of vitamin D was higher than the mean daily intake in the Danish population. Serum 25-HCC was positively correlated to dietary vitamin D intake, but not correlated to the severity of bone changes, indicating that other factors than circulating 25-HCC are responsible for the development of anticonvulsant osteomalacia. Serum 25-HCG was inversely correlated to serum iPTH in patients with a low dietary calcium intake. The mean value of serum iPTH was not increased, and there was no correlation between serum iPTH and bone morphometry.
OESTROGEN FORMATION FROM C19 PRECURSORS IN HUMAN CHORIOCARCINOMA IN CULTURE
Authors: Schut Herman A. J. , Townsley John D. 
Published: December 2008

ABSTRACT
A cloned cell line of human choriocarcinoma was evaluated as a model of human placental oestrogen production. Oestrone formation from dehydroepiandrosterone (D), D-sulphate (DS) or 4-androstenedione (A) was ≦ 5% of oestradiol-17β (Oe2) formation. Oe2 formation from D and A was similar (100–150 pmole/h/107 cells); that from DS was 10 times less. Omitting serum from the medium increased Oe2 yield from DS 4-fold; addition of albumin restored these yields to control values (P > 0.05, t-test), presumably by binding DS. N6,02′-dibutyryl-adenosine 3′,5′-cyclic monophosphoric acid and theophylline treatment for 72 h stimulated (P <0.01) Oe2 formation from D (36 %), DS (66%) and A (183 %). In intact cells, sulphatase activity, Oe2 formation from D and Oe2 formation from DS equalled those in homogenates (P > 0.05) but Oe2 formation from D was greater than that from DS in both systems (P < 0.001), indicating a deficiency of sulphatase relative to subsequent enzymes of oestrogen synthesis. Steroids, at concentrations previously shown to inhibit placental sulphatase or 3β-hydroxysteroid dehydrogenase, did not inhibit choriocarcinoma enzymes. Except for its relative sulphatase deficiency and insusceptibility of oestrogen synthesizing enzymes to steroid inhibitors, choriocarcinoma appears to be a useful model of placental oestrogen synthesis.
EFFECT OF α-MSH ON THE TYROSINASE ACTIVITY AND THE RATE OF MELANIN ACCUMULATION OF MELANOMA CELLS IN VITRO
Authors: Lee Teh H. , Lee Mang S. 
Published: December 2008

ABSTRACT
A stimulation of the tyrosinase activity was observed when melanoma cells isolated from transplantable mouse melanomas were incubated at 37°C for 6 h in the presence of 1–10 × 10−6 m α-MSH. All strains of mouse melanomas studied (B-16, Cloudman S-91 and Harding-Passey), exhibited similar responses. It was also observed that the intact cellular structure of melanoma cells was not required for the ability to respond to α-MSH. The stimulation of the enzymic activity was accompanied by an increase of the rate of incorporation of radioactivity into melanin from L-[U-14C]tyrosine, indicating an enhanced melanogenesis of tumour cells under in vitro conditions.
DECREASED BONE SENSITIVITY OF THYROIDECTOMIZED RATS TO THE CALCAEMIC EFFECT OF 1,25-DIHYDROXYCHOLECALCIFEROL
Authors: Pavlovitch H. , Presle V. , Balsan S. 
Published: December 2008

ABSTRACT
The calcaemic response of thyroidectomized parathyroid transplanted rats to a single dose of biosynthetic 1,25-dihydroxycholecalciferol (50 ng) injected into a jugular vein, was evaluated. The animals were fed a vitamin D-free, low calcium diet. Compared to sham-operated and to thyroidintact parathyroid transplanted rats thyroidectomized animals had a significantly reduced calcaemic response to 1,25-dihydroxycholecalciferol, Daily supplementation with d,l-thyroxine (100 μg/rat) during the experimental period restored a normal response. The increase in serum calcium concentration after 1,25-dihydroxycholecalciferol injection was similar in thyroidectomized bilaterally nephrectomized animals, and in thyroidectomized kidney-intact rats. The results suggest that in thyroxine depleted rats, the sensitivity of bone to the calcaemic effect of 1,25-dihydroxycholecalciferol is decreased.
MITOCHONDRIAL REDOX COMPONENTS OF HUMAN ADRENOCORTICAL STEROID HYDROXYLASES UNDER PHYSIOLOGICAL CONDITIONS AND IN FOCAL HYPERPLASIA OF THE ZONA FASCICULATA
Authors: deAlvare Louis R. , Kimura Tokuji , Singhakowinta Amnuay , Honn Kenneth V. , Chavin Walter 
Published: December 2008

ABSTRACT
Cytochrome P450, aa3 and adrenodoxin were characterized in human adrenocortical mitochondria. Human adrenodoxin demonstrated a distinctive electron paramagnetic spectrum exhibiting anisotropic g values indicative of axial symmetry. The observed g values were g // =2.027, g⊥ =1.940. Adrenodoxin content of crude human adrenal mitochondria was 0.65 ± 0.01 nmol/mg of mitochondrial protein and was in a stoichiometric 1:1 molar ratio with cytochrome P450. Mitochondrial cytochrome P450 (0.62 nmol/mg mitochondrial protein) and aa3 (0.19 nmol/mg mitochondrial protein) levels were determined in a normal human adrenal. A patient receiving ACTH (3d) demonstrated a doubling of P450 content, while cytochrome aa3 levels remained unchanged. ACTH plus hydrocortisone therapy (3d) increased both P450 and aa3 levels, however 24 h hydrocortisone therapy alone was without effect. An area of focal hyperplasia of the zona fasciculata also demonstrated P450 and aa3 levels elevated above the contralateral and normal human adrenal levels. The possibility of hormonal control of human adrenal mitochondrial cytochromes P450 and aa3 is suggested.
EXOGENOUS HORMONE UPTAKE AND RETENTION IN THE RAT UTERUS AT THE TIME OF OVO-IMPLANTATION
Authors: Sartor P. 
Published: December 2008

ABSTRACT
The uterine uptake of tritiated hormones, oestradiol and progesterone, was studied at the time of ovum implantation in the rat. Macromolecular dyes such as trypan blue were used to distinguish implanted sites from the unimplanted ones.
A differential uptake was found between the implanted and unimplanted sites in normal 6th day pregnant females.
Oestradiol was retained more at the unimplanted sites, whereas its half-life was approximately the same at the two levels. On the other hand progesterone was found in greater amounts in the implanted sites due to a difference in half-life for each site (30 min for unimplanted sites, 40 min for implanted ones during the first 30 min following injection). When endogenous oestradiol retention was suppressed by ovariectomy, higher uptake of [3H]oestradiol in unimplanted sites was not found.
These results suggest a heterogeneity in the binding sites of oestradiol in the pregnant uterus.
PERIPHERAL AND CENTRAL ANDROGENIC STIMULATION OF SEXUAL BEHAVIOUR OF CASTRATED MALE RATS
Authors: Hamburger-Bar Rachel , Rigter Henk 
Published: December 2008

ABSTRACT
The effects of androgens on the maintenance and restoration of sexual behaviour (mounts, intromissions and ejaculations) of castrated male rats were studied. In the maintenance study the rats were treated during 5 weeks, starting one day following castration. Testosterone propionate maintained sexual behaviour at an almost normal level. The androgenoestrogen intermediate 19-hydroxytestosterone propionate was unable to prevent the decline in the number of ejaculations over the weeks although this hormone maintained the post-ejaculatory refractory period in those rats that ejaculated and also maintained normal sexual latencies.
In the restoration study administration of testosterone propionate during 7 weeks to long-term castrated rats restored sexual behaviour to normal. 19-Hydroxytestosterone propionate treated rats displayed mounts but no other signs of sexual behaviour. The 5α-reduced androgen dihydrotestosterone propionate did not restore sexual behaviour. Testosterone propionate and dihydrotestosterone propionate stimulated peripheral target organs; 19-hydroxytestosterone propionate was ineffective in this respect. It has been suggested that testosterone might stimulate sexual behaviour in rats in two ways, i. e., via its aromatization to oestradiol in the brain, and by stimulating growth of peripheral tissues via its 5α-reduction to dihydrotestosterone. In support for this view we have found that the combination of 19-hydroxytestosterone propionate and dihydrotestosterone propionate was effective in restoring the full pattern of sexual behaviour in castrated male rats.
COMPARISON OF EFFECTS OF C19 (ANDROSTENE OR ANDROSTANE) STEROIDS ON SERUM GONADOTROPHIN CONCENTRATIONS AND ON ACCESSORY REPRODUCTIVE ORGAN WEIGHTS IN GONADECTOMIZED, ADULT MALE RATS
Authors: Verjans H. L. , Eik-Nes K. B. 
Published: December 2008

ABSTRACT
The effect of subcutaneous administration of graded doses of C19 (androstene or androstane) steroids on serum levels of LH and FSH and on weights of accessory reproductive organs in gonadectomized, adult male rats were investigated. The C19 steroids were administered during 7 days in doses of 100, 50, 25, 12.5 or 6.25 μg per 100 g body weight per day. With the amounts of steroids used, 5α-dihydrotestosterone and 5α-androstane-3α,17β-diol had a high potency in preventing the rise of serum gonadotrophin concentrations and in curbing the decrease of weights of ventral prostates and seminal vesicles following orchidectomy. 5α-Androstane-3β,17β-diol showed no such effects. Positive feedback effects on serum gonadotrophins in castrates were observed following injection of certain doses of some steroids. Effects of steroids on accessory reproductive organs did not always correlate with those on gonadotrophic function of the hypothalamic-pituitary unit.
EVIDENCE FOR A DOPAMINERGIC COMPONENT IN THE SERIES OF NEURAL EVENTS THAT LEAD TO THE PRO-OESTROUS SURGE OF LH
Authors: Clemens James A. , Tinsley Frank C. , Fuller Ray W. 
Published: December 2008

ABSTRACT
The possible participation of dopamine in the neural events that lead to the pro-oestrous surge of luteinizing hormone (LH) was investigated utilizing a dopaminergic ergoline derivative (lergotrile mesylate). Administration of reserpine (2.0 mg/kg, ip) to rats on the day of pro-oestrus depicted brain dopamine and norepinephrine and prevented the LH surge and ovulation. Administration of lergotrile mesylate prior to or at the same time as reserpine prevented the inhibitory effects of reserpine on LH release and on ovulation in about half of the animals. When lergotrile mesylate was given on the morning of pro-oestrus, the LH surge was advanced. The results indicate that there is a dopaminergic component in the series of neural events that precede the surge of LH on prooestrus, and that the dopaminergic stimulus precedes the LH surge by about 4–5 h.
CHANGES IN SERUM LEVELS OF THYROXINE AND THYROXINE-BINDING PROTEINS (TBG, TBPA, ALBUMIN) INDUCED BY VENOUS STASIS
Authors: Jacobsen B. Brock , Petersen B. , Andersen H. 
Published: December 2008

ABSTRACT
Serum concentrations of thyroxine (T4), thyroxine-binding globulin (TBG), thyroxine-binding pre-albumin (TBPA) and albumin were determined in 21 healthy, young subjects before and after a brief venous stasis in two experiments: 1) 3 min stasis induced by a sphygmomanometer with constant pressure 20 mmHg above the diastolic blood pressure and 2) 2 min stasis induced by an arm tourniquet of rubber.
In both experiments the serum T4 level was significantly rised (mean 9 %) after venous compression. Increases of the same magnitude were observed for serum TBG, serum TBPA and serum albumin. The serum concentrations of the free constituents - sodium and creatinine - remained unchanged, whereas the haemoglobin concentration increased (mean 8%). This haemoconcentrating effect of venous stasis seemed to be more pronounced in females than in males. Our data emphasize the need for protein correction procedures when total serum T4 is measured.
ANTIFERTILITY PROPERTIES OF BOVINE PINEAL EXTRACTS: REDUCTION OF OVULATION AND PRE-OVULATORY LUTEINIZING HORMONE IN THE RAT
Authors: Orts R. J. , Kocan K. M. , Johnson R. P. 
Published: December 2008

ABSTRACT
Bovine pineal glands were extracted with acetic acid and partially purified on Sephadex G-25. Three fractions, F3, F4 and F5, were each administered to cycling female rats for 4, 2 or 1 day prior to ovulation to determine their effects on fertility, ovulation and the pro-oestrous surge of luteinizing hormone (LH). The incidence of pregnancy and the mean number of foetuses were reduced in animals after treatment with F3 or F4 but not in those treated with F5. Each of the F3 and F4 fractions significantly reduced the mean number of ova shed and the pre-ovulatory concentration of serum LH. The F5 fraction caused a moderate reduction of the pro-oestrous rise of serum LH but had no significant effect on ovulation. The data suggest that fertility in rats can be reduced by more than one substance of low molecular weight present in bovine pineal extracts through a modifying effect on LH secretion and subsequent ovulation.
EFFECT OF PROLACTIN INHIBITORY AGENTS ON THE ECTOPIC ANTERIOR PITUITARY AND THE MAMMARY GLAND IN RATS
Authors: Gräf K.-J. , Horowski R. , El Etreby M. F. 
Published: December 2008

ABSTRACT
The purpose of the present study was to investigate the biological effectiveness of two highly potent prolactin (PRL) inhibitors, lisuride hydrogen maleate (LMH) and 2-Br-α-ergocryptine (CB-154), in the absence of hypothalamic factors acting directly at the level of the anterior pituitary. Hypophysectomized female rats bearing 4 transplanted pituitaries beneath the kidney capsules were treated with oestradiol benzoate (OeB) and progesterone (P) with or without simultaneous administration of LHM or CB-154 for 22 days in order stimulate or inhibit lobulo-alveolar growth of the mammary glands. In addition to the investigation of the mammary glands by DNA determination and assessment of the histological pictures, the aim of this study was directed towards the influence of the substances tested at the level of the anterior pituitary remote from the hypothalmus. In this connection the changes in the different cells within the ectopic pituitaries as revealed by immunoenzyme-cytochemical studies were investigated.
The results obtained support the classical view of a neuroendocrine regulation of mammary gland growth and the importance of oestrogens, P and PRL within this system. Both ergot derivatives LHM and CB-154 were able to antagonize the stimulatory effect of OeB combined with P on the mammary gland. With regard to the mechanism of action of LHM and CB-154 it is concluded that both substances act via a direct action on dopaminergic receptors within the ectopic anterior pituitary.
THE THYROTROPHIN RESPONSE TO THYROTROPHIN RELEASING HORMONE DURING TREATMENT IN PATIENTS WITH GRAVES' DISEASE
Authors: Haug E. , Frey H. M. M. , Sand T. 
Published: December 2008

ABSTRACT
Thyrotrophin releasing hormone (TRH) tests were performed at 4 or 8 weeks intervals, after the initiation of anti-thyroid treatment in 15 patients with Graves' disease. All TRH tests were negative as long as the serum levels of thyroxine (T4) and triiodothyronine (T3) were elevated, and normalization of the serum levels of these hormones always occurred before the response to iv TRH was restored. In 13 patients the time from the patients for the first time were registered as biochemically euthyroid varied from 0–9 months (mean 3.1 months), before normal TRH response was restored. Two patients were still TRH non-responsive at the end of the study, even though they had been biochemically euthyroid for as long as 17 and 18.5 months. The TRH test, therefore, is not helpful in the evaluation of the effect of anti-thyroid treatment in patients with Graves' disease.
There was an increase in the serum level of thyrotrophin (TSH) from 3.4 ± 0.3 (sem) to 4.3 ± 0.5 (sem) ng/ml (P <0.05), and a decrease in the serum level of total T4 from 19.4 ± 1.1 (sem) to 5.8 ± 0.8 (sem) μg/100 ml in 13 patients from the first examination until the last time they were examined before restored TRH response. This finding shows that the pituitary gland has retained its ability to synthesize and secrete TSH even though no TSH could be released by iv TRH. In 6 TRH non-responsive patients with Graves' disease, serum TSH levels were suppressed from 2.5 ±1.2 (sem) ng/ml before the administration of a single dose of 3 mg T4 orallly, to 0.9 ± 0.2 (sem) ng/ml, 7 days after the T4 administration. Thus, the negative feed-back effect on the pituitary gland of the thyroid hormones is operating in these patients.
This finding indicates that the TRH non-responsiveness in euthyroid patients with Graves' disease is not due to pituitary depletion of TSH, since the negative feed-back effect of the thyroid hormones is operating normally.
LONG-TERM TURNOVER OF THYROID IODINE IN THE RAT AS STUDIED BY THE ISOTOPIC EQUILIBRIUM METHOD
Authors: Bastiani Paul , Simon Claude 
Published: December 2008

ABSTRACT
A long-term kinetics study was made in rats in a steady state for iodine metabolism and receiving either 5 μg iodine (group 5) or 50 μg iodine (group 50) daily. By using the isotopic equilibrium method, the value of the renewed fraction was followed during at least 120 days in the thyroglobulin (Tg) and the lysosomes of the thyroid and in the plasma hormones.
For both groups, only part of the total iodine pool in the Tg as well as in the lysosomes is directly available for secretion. Furthermore, the direct precursor pool of iodine for secretion in the lysosomes is dependent on the daily iodine intake (1.3 times greater in group 50 than in group 5) while the Tg iodine supply in the colloid is not (80 % of the total Tg iodine pool for both groups).
An iodine pool with a very slow turnover is present in the lysosomes (about 50 % in each group), in the Tg of group 5 (more than 15 %) and probably in the Tg of group 50 (less than 5 %). Thus, the distribution of such a pool between lysosomes and Tg is dependent on the daily iodine intake.
The very slow iodine pool is probably not accumulated into the follicles, since every studied pool is in steady state. It is practically not secreted since hormones in the plasma are entirely renewed. Again, it is practically not deiodinated since the thyroid iodide pool is also entirely renewed. These three criteria are valuable for both groups.
Although one cannot entirely exclude its participation in secretion, it is postulated that the major part of this pool is re-cycled without deiodination. Both lysosome-lysosome and lysosome-colloid pathways of re-cycling have been postulated. The second pathway is supposed to increase when the daily iodine intake is decreased.