bluuebunny/crossref_metadata_2025_split huggingface dataset:
A comparison of metabolic clearance rates of oestradiol-17β in immature and peripubertal female pigs and possible implications for the onset of puberty
Authors: Elsaesser F. , Stickney K. , Foxcroft G. 
Published: December 2008

Abstract.
A continuous infusion technique of either [3H]oestradiol-17β (E2) or unlabelled E2 was used to investigate suggested differences in the metabolic clearance rate of oestradiol-17β (MCR-E2) in immature and peripubertal female pigs. Using the isotope infusion technique, the following values were obtained: 60 day old gilts; MCR-E2 = 2133 ± 274 ([unk] ± sem) ml/min, MCR-E2/kg BW = 116 ± 14.5 ml/min kg, and conversion ratio (CR) of E2 to oestrone (E1) = 31.6 ± 3.7%. The respective values for 160 day old gilts were: MCR-E2 = 3027 ± 340, MCR-E2/kg BW = 48.5 ± 4.82, and CR = 15.9 ± 2.12. Except for a significant difference in the weight related MCR-E2 data for the 60 day old group, similar values were found following infusion of unlabelled E2. The percentage of radioactivity extractable with ether from plasma was 22.6 ± 3.0% and 27.2 ± 2.0%. Fifty-seven and 66% of total radioactivity infused was recovered in the urine within 12 h in 60 and 160 day old gilts, respectively. There was no difference in the percentage binding of E2 to plasma proteins as determined by equilibrium dialysis (80%). It is concluded that in addition to an activation of ovarian steroidogenesis during puberty, a gradual maturational decrease in the MCR-E2/kg BW might play a role in raising plasma E2 concentrations and thus in constituting an effective oestrogen feedback signal, which results in the first pre-ovulatory LH-surge.
The effect of hyposmotic and sodium chloride hyperosmotic environments on the secretion and synthesis of prolactin from human decidua in vitro
Authors: Andersen Jesper Rye , Borggaard Birgit , Ørnvold Kim , Knoth Mogens 
Published: December 2008

Abstract.
Using a paired design as well as a cross-over design both with 16 h incubation periods, we have incubated human decidua in hyposmotic, isosmotic, and sodium chloride hyperosmotic media. In the cross-over design each tissue aliquot was subjected to 3 media with different osmolalities, one of which was isosmotic. Thus, intensive utilization of the tissue was possible.
The results of the cross-over study were identical with the result of the paired design. We found a decreased secretion of prolactin in hyposmotic environments, whereas hyperosmotic environments up to an osmolality about 400 mmol/kg gave a dose related increase in the prolactin secretion into the medium as well as in the total content of prolactin in the tissue and the medium. Excessive hyperosmotic medium decreased the secretion. The enhanced secretion was an effect of increased production, which could be blocked by cycloheximide. We found no feedback of prolactin on its own secretion.
Endogenous androgen levels in epithelium and stroma of human benign prostatic hyperplasia and normal prostate
Authors: Bartsch W. , Krieg M. , Becker H. , Mohrmann J. , Voigt K. D. 
Published: December 2008

Abstract.
5α-Dihydrotestosterone (DHT) and 5α-androstane-3α, 17β-diol (3α-diol) were extracted from epithelium and stroma of human benign prostatic hyperplasia (BPH) and of normal prostate and quantified by RIA. The main results were: (1) concerning the BPH, DHT is mainly located in the nuclear fraction of epithelium and stroma, whereas 3α-diol was completely of extranuclear origin, (2) in the nuclei derived from BPH stroma the DHT content (7.1 ± 0.88 pmol/mg DNA, mean ± sem [n = 14]) was significantly higher (P < 0.01) than in the nuclei derived from BPH epithelium (3.8 ± 0.38 pmol/ mg DNA [n = 14]). The DHT content in the nuclear fraction derived from unseparated, i.e. whole tissue, was 5.6 ± 0.60 pmol/mg DNA [n = 14], (3) the biological significance of the overwhelming DHT accumulation in the stromal nuclei for the BPH tissue is reflected by a significant correlation between the DHT values in the nuclei from stroma and whole tissue (rs = 0.710, P < 0.01) and (4) in four normal prostates the DHT content in the nuclear fraction of epithelium (1.3 ± 0.37 pmol/mg DNA) and stroma (2.2 ± 0.93 pmol/mg DNA) was significantly lower (P < 0.01, each) compared with the respective BPH fraction. These data support earlier findings which indicate that the stroma of BPH is a preferential tissue for androgen metabolism.
Dynamics of Prl release in galactorrhoeic normoprolactinaemic women
Authors: D'Agata R. , Aliffi A. , Maugeri G. , Mongioì A. , Vicari E. , Gulizia S. 
Published: December 2008

Abstract.
Prl responsiveness to TRH and sulpiride was evaluated in 14 galactorrhoeic normoprolactinaemic women. Radiological signs of sellar alteration were present in 6 of these patients. Pituitary responses to TRH did not differ from those obtained in a group of 16 healthy women. Serum Prl levels after sulpiride were higher in the patients than in the controls (P<0.01). The Amax response was 256 ± 16 SE vs 158 ± 10.6 ng/ml in the control group (P<0.01). The mean integrated area after sulpiride was also greater (20738 ± 1263 se ng/ml/2 h vs 13 188 ± 408) (P< 0.01).
The markedly enhanced Prl response to sulpiride in our patients with galactorrhoea could be due to a functional disorder of the hypothalamic-pituitary axis or to a lactotrope hyperplasia.
Circulating TSH-binding inhibiting immunoglobulins in myasthenia gravis
Authors: Kiessling W. R. , Finke R. , Kotulla P. , Schleusener H. 
Published: December 2008

Abstract.
Using a radioligand receptor assay the sera of 46 patients with myasthenia gravis (MG) were tested for the presence of circulating TSH-binding inhibiting immunoglobulins (TBII). In addition thyroid function was evaluated on the basis of T3, T4, TBG and TSH radioimmunoassays including the TRH stimulation test. Circulating antimicrosomal and antithyroglobulin thyroid antibodies were measured by haemagglutination techniques. Two patients had concomitant Graves' disease (GD), 5 were euthyroid with autonomously functioning thyroid tissue due to non-immunogenic multinodular goitre and 39 myasthenic patients were euthyroid with normal pituitary thyroid axis. Only 1 patient with GD had strongly positive TBII-activity and 3 euthyroid MG patients were TBII borderline-positive.
Inhibition by early treatment with bromocriptine of spontaneous mammary tumour development in rats with no side-effects
Authors: Nagasawa H. , Morii S. 
Published: December 2008

Abstract.
Temporary inhibition by CB-154 (bromocriptine) of pituitary prolactin secretion, which induced a decline in mammary gland DNA synthesis for 4–11 weeks of age, resulted in a marked suppression of spontaneous mammary tumour development in rats after one year of age. The treatment had no effect on reproduction and subsequent lactation immediately after the CB-154 injection or growth and function of the mammary glands and pituitary prolactin secretion in later life.
Dopaminergic suppression of pancreatic somatostatin secretion
Authors: Itoh Mitsuyasu , Furman Brian L. , Gerich John E. 
Published: December 2008

Abstract.
To characterize dopaminergic influences on pancreatic islet D cell function and its potential interaction with islet A and B cell function, the effect of dopamine (0.5–100 μm) on immunoreactive somatostatin (IRS), insulin (IRI), and glucagon (IRG) release from rat islets incubated in vitro was studied. Dopamine significantly suppressed the release of IRS (P< 0.001) and IRI (P < 0.001) and augmented IRG release (P < 0.001). Maximum suppression of IRS and IRI release was evident at 20 μm dopamine with half-maximal suppression occurring at 0.5–1 μm. Maximal stimulation of IRG release was observed at 100 μm dopamine with a halfmaximal response occurring at 5–10 μm. Suppression of IRS secretion by dopamine (20 μm) was completely reversed by the dopaminergic antagonists haloperidol (5 μm) and pimozide (5 μm), but was only partially reversed by the alpha adrenergic antagonist phentolamine (2 μm), and was further suppressed by the beta adrenergic antagonist propranolol (2 μm). Suppression of IRI release by dopamine was completely reversed by propranolol, but was unaffected by haloperidol, pimozide, and phentolamine. There results indicate that dopamine directly affects pancreatic islet D cell function, and that islet B and D cells appear to be more sensitive to dopamine than are A cells. Dopamine suppresses IRS secretion predominantly through activation of dopaminergic receptors, whereas it suppresses IRI release through an alpha adrenergic mechanism and stimulates IRG release through a beta adrenergic mechanism.
Relationships between fat and plasma androstenone and plasma testosterone in fatty and lean young boars during growth and after hCG stimulation
Authors: Bonneau M. , Meusy-Dessolle N. , Léglise P. C. , Claus R. 
Published: December 2008

Abstract.
The effect of weight of fatty tissue on fat and plasma androstenone and on plasma testosterone relationships in the young boar was studied. For this purpose, hCG stimulation of steroid testicular production was performed in 12 boars and fat androstenone concentration subsequently measured. In addition plasma androstenone and testosterone were determined in 8 of them, previously cannulated.
The results show that: 1) although plasma testosterone response to hCG stimulation was similar in all boars, fat and plasma androstenone responses were very variable between boars, 2) weight of fatty tissue appeared to have little influence, if any, on androstenone exchanges between plasma and fatty tissue and 3) plasma androstenone/testosterone ratio appeared to be less variable within boars than between boars.
The data show that there is probably some between-boars-variability in the respective rates of elimination of testosterone and androstenone.
The effect of glibenclamide on plasma insulin, plasma somatomedin bioactivity and skeletal growth in hypophysectomized rats
Authors: Heinze E. , Ranke M. , Manske E. , Vetter U. , Voigt K.-H. 
Published: December 2008

Abstract.
Male rats, body weight 60–75 g, were hypophysectomized. Three days after operation the animals were divided into two groups. Group B received solvent solution and group C 1 mg/kg body weight per day of glibenclamide ip for the following 9 days. Group A consisted on non-operated normal rats. Twenty-four hours after the last injections and after a 12 h overnight fast the body weights of groups B and C were not different, the increase during the 10 days being 10% in both groups. Serum insulin (IRI) was significantly higher in group C than in group B (C: 8.0 ± 0.3 μU/ml, n = 14 vs B: 4.9 ± 1.0 μU/ml, n = 14; P < 0.01, mean ± sem) as was serum somatomedin bioactivity (SM)-porcine cartilage assay — (C: 1.06 ± 0.1 U/ml, n = 14 vs B:0.41 ± 0.01 U/ml, n = 14; P < 0.001). Skeletal growth was determined with the tibia test and by a radiograph of each rat. The width of the proximal epiphyseal growth plate of the tibia was significantly increased in group C compared to group B (C: 204 ± 4.8 μm, n = 12 vs 181 ± 6.5 μm, n = 13; P < 0.005). On the radiograph the area of the right femur was not different between the two groups of animals, while the height and the area of the first lumbar spine were significantly augmented in group C. The results show that glibenclamide stimulates IRI, SM and skeletal growth in hypophysectomized rats.
Compared to the glibenclamide treated hypophysectomized animals the normal rats of group A had doubled their body weights. IRI (59 ± 5 μU/ml, n = 4) and skeletal growth (tibia test: 454 ± 5.8 μm) were greatly increased. SM did not differ between group A (1.21 ± 0.35 U/ml and group C. T4 was much lower in group B (0.64 ± 0.09 μg/100 ml, n = 5) than in group A (4.1 ± 0.3 μg/100 ml, n = 6; P < 0.001).
It is concluded that a normal SM concentration is not necessarily associated with appropriate growth.
The effects of thyroxine and triiodothyronine on the thyrotrophin response to thyrotrophin-releasing hormone in normal and iopanoic acid-treated euthyroid rats
Authors: Boado Rubén , Ulloa Edgardo , Zaninovich Angel A. 
Published: December 2008

Abstract.
The present work studied the TSH response to TRH in T4- and T3-treated normal rats and in rats with depressed intrapituitary conversion of T4 to T3. Euthyroid normal rats were injected iv with a single dose of 6 μG T4/100 g body weight, 1 μg T3/100 g or normal saline. Another group treated with iopanoic acid (IOP) received 1 or 10 μg T4/100 g, 0.21 or 2.5 μg T3/100 g, or saline as control. Twenty min later 1 μg TRH/100 g was injected iv. Blood samples were drawn at times 0, 20 min (immediately preceding the injection of TRH) and 30 min (10 min post-TRH) for measurement of plasma T4, T3 and TSH. Other groups of IOP-treated rats were injected iv with 150 μCi of [3',5'-125I]T4; the hypophyses were removed at 30 min and homogenized in PBS buffer, extracted and chromatographed in tertiary amyl alcohol:hexane:ammonia. The control group of rats had a 13-fold increase in plasma TSH 10 min after the TRH injection, while rats treated with 6 μg T4/100 g had a 7.6-fold increase (P < 0.01 vs control increment) and rats treated with 1 μg T3/100 g had no change in TSH response as compared to controls. In IOP-treated rats injected with 10 μg T4/100 g there was a smaller increase in the TSH response to TRH as compared to control (P < 0.01), and a similar smaller response was seen in rats treated with 2.5 μg T3/100 g (P < 0.01 vs control). IOP-treated animals given 1 μg T4 or 0.21 μg T3/100 g had no significant changes in TSH response to TRH. It seems probable that T4 possesses an intrinsic hormonal capacity to regulate the secretion of TSH before it monodeiodinates to T3.
Dissociation of growth and function in the rat thyroid during prolonged goitrogen administration
Authors: Wynford-Thomas D. , Stringer B. M. J. , Williams E. D. 
Published: December 2008

Abstract.
This study was designed to investigate the changes in growth and function which occur in the rat thyroid during prolonged TSH stimulation.
Animals maintained on the goitrogen aminotriazole were sacrificed together with controls at frequent intervals over a period of 5 months. The levels of serum T3 and T4 and TSH were measured by radioimmunoassay. Functional activity was assessed by measurement of the thyroid/serum iodide ratio (T/S) and growth by measurement of thyroid weight, follicular cell number and follicular cell mitotic activity.
Serum T3 and T4 rapidly fell to undetectable levels within 2 weeks. The level of serum TSH rose to a stable 5-fold maximum after 4 weeks. The T/S ratio followed a closely similar pattern rising to a sustained 7-fold maximum. Thyroid weight and follicular cell number increased rapidly for the first few weeks but the growth rate declined progressively, falling almost to zero after 80 days. Mitotic activity rose dramatically to a 30-fold peak after 7 days but then declined almost to normal after 80 days, consistent with the observed change in cell number. The results thus demonstrate a clear dissociation between the functional and proliferative activity of the thyroid follicular cells during prolonged stimulation by a sustained elevation of serum TSH and point to the existence of specific growth regulating mechanisms which limit the mitotic response.
Responses of plasma catecholamine and plasma renin activity after glucagon stimulation in essential hypertension
Authors: Uda Masanobu , Sakamoto Noboru , Tsuchiya Masayuki , Ito Keiichi , Ikeda Masao , Matsukura Shigeru , Fujita Takuo 
Published: December 2008

Abstract.
To investigate the roles of the sympatheticoadrenomedullary system and the renin-angiotensin system in the pathogenesis of essential hypertension, the levels of plasma catecholamine and plasma renin activity (PRA) after glucagon-stimulation were evaluated.
In 9 patients with essential hypertension whose levels of PRA were either normal or high (NHREH), iv bolus injection of 1 mg glucagon caused a rapid and significant increase in plasma epinephrine concentration from the basal values of 170 ± 25 pg/ml, mean ± sem to 314 ± 30 pg/ml (P < 0.05) at 5 min after the injection, reaching the mean peak values of 358 ± 87 pg/ml (P < 0.05). Plasma norepinephrine also rose from the basal values of 357 ± 50 pg/ml to the peak values of 1065 ± 231 pg/ml (P < 0.02) while increase in PRA was detected in 4 of 9 patients.
In 7 patients with low renin essential hypertension (LREH), plasma epinephrine failed to increase after glucagon stimulation whereas plasma norepinephrine increased significantly from the basal values of 391 ± 77 pg/ml, reaching 1212 ± 274 pg/ml at their peak values (P < 0.01). There was no discernible response of PRA to glucagon.
These results suggest that both epinephrine secretion from adrenal medulla and renin release from juxtaglomerular (JG) cells after glucagon injection are impaired in LREH in contrast to their significant responses observed in NHREH. It also indicates that glucagon load may be useful for the simultaneous assessment of the reserve of both renin secretion and sympatheticoadrenomedullary function in essential hypertension.
Conversion of progesterone by testicular tissue of cryptorchid rats
Authors: Ficher Miguel , Steinberger Emil 
Published: December 2008

Abstract.
The capacity of adult rat testes rendered surgically cryptorchid to metabolize progesterone1 was investigated at several time intervals (7, 14, 28 and 42 days) after surgery. Testicular tissue was incubated with [3H]progesterone, the steroid metabolites were isolated and purified using paper and thin layer chromatography, and further identified by isotopic dilution and recrystallization to constant 3H/14C ratio or constant specific activity (dpm/μmol). A sharp decrease in the accumulation of testosterone, concomitant with a marked increase in accumulation of 17α-hydroxyprogesterone, was observed as early as 7 days after surgery. No further major changes were observed at 14 or 28 days after surgery. However, at 42 days, accumulation of testosterone was substantially increased, while that of 17α-hydroxyprogesterone decreased to trace levels. 20α-Dihydroprogesterone was detected at different time intervals after surgery. The data suggest that cryptorchidism inhibits the activity of 17–20 desmolase for the first 4 weeks after surgery. The activity of this enzyme is restored by the 42nd day and the metabolic pathway between progesterone and testosterone resembles that of an intact rat. The factors responsible for this spontaneous restoration of the biosynthetic pathway are under investigation.
Serum somatomedin activity assayed by the enhancement of proteoglycan sulphation using chick embryo chondrocytes in normal children at various ages and childen of short stature
Authors: Maesaka Hatae , Yokoya Susumu , Tachibana Katsuhiko , Suwa Seizo , Yamagata Tatsuya 
Published: December 2008

Abstract.
It was possible to obtain a sufficient amount of homogeneous chondrocytes from 13-day old chick embryo-sterna in an 8-day suspension culture. Serum somatomedin (SM) activity was measured on the basis of the ability of serum to stimulate labelled sulphate uptake in these chondrocytes. Somatomedin A and multiplication stimulating activity (MSA) stimulated the sulphation in this assay. Serum SM activity in term cord sera and newborn sera was lower than that in normal adults. Serum SM activity in early infants increased rapidly and attained the levels of that in normal adults within 1 month following birth. Serum SM activity in infants (1 month—2 years) and pubertal children (10–16 years), when the annual height increment is greatest, was higher than that in normal adults.
Serum SM activity in children with constitutinal dwarfism aged 6–10 years and over 10 years was normal and lower, respectively, compared to that in age-matched controls.
Pituitary dwarfs had markedly low SM activity compared to age-matched controls. Diagnostic evaluation of serum SM activity in children requires comparison with age-matched controls. Assay for serum SM activity may provide a useful and simple procedure for differentiating the cause of growth disorders from growth hormone deficiency.
Successful pregnancy in an acromegalic patient during 2-Br-α-ergocryptine (CB-154) therapy
Authors: Miyakawa Isao , Taniyama Keiichi , Koike Hiroyuki , Mori Norimasa , Nagamine Motohisa , Kuribayashi Tadanobu , Araki Shukuro 
Published: December 2008

Abstract.
Foeto-placental function and hormone levels in the maternal, foetal and amniotic compartments have been investigated in an acromegalic woman who was treated with 20 mg bromocriptine/day throughout gestation. Bromocriptine therapy during pregnancy had no effect on urinary oestriol excretion and plasma levels of unconjugated oestriol, progesterone, human placental lactogen, cystine aminopeptidase and heat-stable alkaline phosphatase. The maternal and foetal (cord) blood and amniotic fluid showed prolactin levels of 3.8, 6.5 and 1700 ng/ml, respectively, in the 39th week of pregnancy during bromocriptine therapy. Compared with data from normal pregnancies, these values demonstrated that bromocriptine or an active metabolite crossed the term placenta to suppress prolactin secretion from the foetal pituitary gland and that the prolactin level in amniotic fluid was scarcely affected by the drug. Maternal, foetal and amniotic fluid growth hormone levels were 27.0, 33.0 and 3.8 ng/ml, respectively, thus indicating that dopamine agonists suppress growth hormone only in acromegalic patients, and not in normal babies. Bromocriptine had no effect on thyroid-stimulating hormone concentrations in the maternal, foetal and amniotic compartments.
A characterisation of cyclic AMP release from monolayer cultures of normal human thyroid cells
Authors: Bidey Stephen P. , Marshall Nicholas J. , Ekins Roger P. 
Published: December 2008

Abstract.
The thyrotrophin (TSH)-dependent and time-related release of cyclic AMP has been characterised in primary monolayer cultures of normal human thyroid cells. Accumulation of cyclic AMP within the incubation medium was detectable within 1 h of exposure of cultures to 5 mU TSH/ml, and increased throughout of subsequent 15 h incubation period, final levels attained being consistently in excess of the corresponding intracellular cyclic AMP levels. Accumulation of cyclic AMP in the incubation medium was dependent on TSH dose, for both short (1 h) and prolonged (16 h) incubations. Moreover, after incubation for 16 h, cyclic AMP levels in the incubation medium were significantly (P < 0.01) in excess of intracellular levels for each dose of TSH tested above 0.2 mU/ml. In the absence of TSH, accumulation of cyclic AMP in the incubation medium remained low, after both 1 h and 16 h incubation periods.
A consideration of these observations suggests that a bioassay based upon the cyclic AMP content of incubation medium samples should provide a more precise detection system for thyroid stimulators than those measuring the intracellular cyclic AMP response, and this has been demonstrated for a cell preparation in which the intracellular response to TSH was minimal.