bluuebunny/crossref_metadata_2025_split huggingface dataset:
Independence of the androgen-induced mRNA synthesis on exogenous glucose in the ventral prostate of the rat
Authors: Kuosa Anja 
Published: December 2008

Abstract.
Poly (A)-containing RNA species were isolated from prostatic polysomes after administration of testosterone to castrated rats. After exposure of prostatic tissue to radiolabelled uridine in vitro for 1 h the radioactivity of polysomal poly (A)-RNA increased at 6–12 h after testosterone treatment, which coincides with the hormonal activation of protein synthesis under the same experimental conditions. The increased radioactivity of polysomal mRNA was not due to changes in the uptake and phosphorylation or radiolabelled uridine or in the endogenous content of uridine nucleotides representing thus an increased mRNA content.
Electrophoretic patterns of double-labelled polysomal mRNA failed to show detectable amounts of androgenspecific species. The larger part of increase in mRNA content thus consists of mRNAs common to prostatic cells of both testosterone-treated and non-treated castrated animals.
The hormonal stimulation of polysomal poly (A)-RNA accumulation was not dependent upon exogenous glucose which is in contrast to protein synthesis. However, glucose was necessary for the hormonal activation of the phosphorylation of [3H]uridine leading ultimately to increased labelling of all RNA species. It is concluded that increased accumulation of polysomal mRNA may be necessary, but not sufficient for the hormonal activation of protein synthesis.
Ultrastructural characterization of human corticotrophs (ACTH cells)
Authors: Tsumuraya Masaru , Kameya Toru 
Published: December 2008

Abstract.
Ultrastructural characterization of human corticotrophs (ACTH cells) was performed by 'superimposition technique', which enabled detailed ultrastructural observation of immunoreactive ACTH cells in adjacent semi-thin light microscopic immunoperoxidase and routine electron microscopic sections. The human corticotrophs were large and round or polygonal and were not stellate. They had scanty rough endoplasmic membranes and were packed with numerous large secretory granules measuring from 250 to 500 nm in diameter. The sizes of secretory granules in 6 human pituitaries were 448 ± 128, 344 ± 86, 448 ± 117, 244 ± 65, 316 ± 76, and 340 ± 93 nm, respectively. The granules were not seen in a single row along the plasma membrane as is the case in the rat. They possessed somewhat irregular outlines with a rarely discernible halo. Different densities of granule matrices were occasionally found. The cells often contained a few large heterogeneous vacuoles. From these findings, the human ACTH cells were recognized to be remarkably different in cell shape and size, properties of secretory granules and cytoplamic inclusions from those of the rat pituitary gland. In respect to secretory granule properties, the human ACTH cells are similar to those of some other mammals (fox, young pig, and lerot). More data is required to elucidate the relationship between human ACTH cell morphology and functional state.
Episodic secretion of vasopressin in man
Authors: Hammer M. , Engell H. C. 
Published: December 2008

Abstract.
The plasma arginine vasopressin concentration (pAVP) was measured in blood samples obtained from an internal jugular vein of 8 patients who under-went surgery for a carotid artery stenosis. Ten blood samples were taken with 1 min interval during the operation. Arterial pAVP was measured in 10 simultaneous samples from a radial artery and the brain veno-arterial difference of pAVP was calculated. The veno-arterial difference was 0–3 pg/ml in 7 of the patients, while it increased to 35 pg/ml upon baroreceptor stimulation in one patient. A pulsatile pattern was found in the veno-arterial difference of pAVP both at low and higher peripheral pAVP levels. This appeared to reflect a discontinuous release of AVP from the neurohypophysis. The described method results in a more accurate picture of ongoing secretory activity than can be obtained by measurements of peripheral pAVP alone. The general usefulness of the method, however, is restricted by the need of a multitude of samples and the difficult approach to the internal jugular vein.
Improved radioassay for human antithyroglobulin
Authors: Beall Gildon N. , Parslow Margaret E. , Kruger Sally R. , Zaidi Azra 
Published: December 2008

Abstract.
Human antithyroglobulin (anti-HTg) in serum and tissue cultures can be assayed by coprecipitation with 125I-labelled human thyroglobulin (HTg). Coprecipitation of the antibody from different sera gives roughly parallel curves, so that a standard serum can be used for quantitiation of other sera. By assessing the binding of 125I-labelled HTg in antigen excess we estimate the antibody content of the standard serum to be 0.14 ng anti-HTg per ml. Shortened incubation minimizes non-specific binding of HTg to serum globulins and obviates pre-assay absorption of HTg. Radioassay for thyroglobulin antibodies in serum correlated with values obtained by solid-phase competitive-binding assay (SPCB). One unit in our assay corresponds to 0.014 unit by the latter assay and to 0.12 units of MRC Research Standard A. We confirm that serum thyroglobulin seriously interferes with SPCB assay, giving what appears to be positive results for anti-HTg where none is detected with our assay. Values for anti-HTg are depressed by serum HTg but only in the presence of very high concentrations in serum.
Desensitisation of rat thyroid to the growth-stimulating action of TSH during prolonged goitrogen administration Persistence of refractoriness following withdrawal of stimulation
Authors: Wynford-Thomas D. , Stringer B. M. J. , Williams E. D. 
Published: December 2008

Abstract.
We have previously shown that administration of goitrogen to the rat leads to a sustained elevation of serum TSH but to only a short-lived burst of mitotic activity in the thyroid, growth eventually ceasing after a few months. This work investigates the possibility that this progressive desensitisation may result simply from continued exposure to high levels of TSH and examines the effect of a period of interruption of goitrogen treatment on the sensitivity of the gland to subsequent TSH stimulation.
Rats were treated with the goitrogen aminotriazole (ATA) for an initial period of 80 days to reach the plateau of thyroid growth. ATA was then withdrawn for 25 days and subsequently re-introduced for a further 35 days. Animals were killed in groups of 8 at frequent intervals and the following measurements carried out: — Serum TSH, T3 and T4, thyroid weight, follicular cell number and mitotic activity.
The initial period of ATA treatment led to a 5-fold increase in serum TSH, a 10-fold increase in thyroid weight and a 9-fold increase in follicular cell number. Mitotic activity stabilised at a few times control levels. Following withdrawal of ATA, TSH and mitotic activity fell to below normal. Thyroid weight fell by 66% but there was no significant fall in follicular cell number. Re-introduction of ATA simply led to a return of all variables to their previous 'stimulated' levels. There was no second burst of mitotic activity and no renewed thyroid growth.
The results show that the desensitisation of follicular cells to the growth-stimulating action of TSH following prolonged stimulation is not reversed by withdrawal of the stimulus, and is therefore unlikely to be mediated by a 'downregulation' at receptor or post-receptor level of the type observed for functional responses in vitro.
Other possible mechanisms are discussed.
Protection by nicotinamide against streptozotocin-induced reduction in pancreatic TRH
Authors: Kazumi Tsutomu , Utsumi Masafumi , Hirose Yoshikazu , Ishihara Kazuhide , Makimura Hiroyuki , Ejiri Kazushige , Taniguchi Hiroshi , Baba Shigeaki 
Published: December 2008

Abstract.
The concentration of thyrotrophin-releasing hormone (TRH) immunoreactivity was determined in pancreatic islets and acini in the rat. In addition, timecourse changes in TRH in response to an iv injection of streptozotocin (65 mg/kg body weight) with or without nicotinamide (500 mg/kg body weight) were examined in the whole pancreas. Furthermore, pancreatic TRH was measured in diabetic rats treated with insulin for 3 weeks. The TRH concentration in rat islets was 42-fold higher than in exocrine glands, indicating that the majority of pancreatic TRH is of islet origin. The mean concentration of pancreatic TRH decreased to 60 and 65% of the respective control values at 4 and 7 h after administration of streptozotocin, respectively. At 24 h, it fell to 10% of control values without significant changes in TRH levels in the hypothalamus and gastrointestinal tract. In contrast, no significant change in pancreatic TRH was noted in rats given combined treatment with streptozotocin and nicotinamide. The injection of streptozotocin alone resulted in severe hypoglycaemia at 7 h and hyperglycaemia at 24 h, whereas neither resulted from the combined treatment. Insulin therapy had no influence on the decreased TRH concentrations in the diabetic pancreas. These results suggest that TRH may be localized to the B cells of pancreatic islets, and that the marked reduction in TRH in diabetic pancreases is not a metabolic consequence of insulin deficiency.
Modification by Su-10'603 of the response to histamine on the production of cortisol and corticosterone in isolated canine adrenocortical cells
Authors: Hirose T. , Matsumoto I. , Aikawa T. 
Published: December 2008

Abstract.
The effect of Su-10'603 on the cortisol and corticosterone response to histamine in dispersed canine adrenocortical cells was examined. The production of cortisol and corticosterone in isolated dog adrenocortical cell incubations increased in a dose-dependent manner at concentrations of histamine between 0.01 and 10.0 μg/ml medium, with the predominant production of cortisol. When Su-10'603 (0.005 to 5.0 μg/ml medium), an inhibitor of 17α-hydroxylation on corticosteroidogenesis, was added in cell incubations with histamine (1.0 μg/ml medium), the production of cortisol decreased in a reciprocal fashion, with a concomitant increase of corticosterone production. At the concentration between 0.05 and 0.1 μg Su-10'603/ml medium, there was a shift from cortisol to corticosterone as the predominant product. These results indicate that in the dog, histamine at pathophysiological concentration stimulates steroidogenesis and acts at a relatively early stage in the biosynthetic pathway.
Lipoproteins during oral and cutaneous administration of oestradiol-17β to menopausal women
Authors: Fåhraeus Lars , Larsson-Cohn Ulf , Wallentin Lars 
Published: December 2008

Abstract.
Thirty-eight post-menopausal women were randomly allocated to substitution treatment with either oestradiol-17β orally (2–4 mg) or cutaneously (3 mg). The concentrations of cholesterol (C), triglycerides (TG) and phospholipids were determined in the high density lipoprotein (HDL)-, the low density lipoprotein (LDL)- and the very low density lipoprotein (VLDL)- fractions twice before medication and after 2, 4 and 6 months of treatment.
Both treatments gave satisfactory clinical results. Oral doses increased the HDL and decreased the LDL thus raising the HDL-C/LDL-C ratio. The higher oral dose also increased the TG concentration. Cutaneous oestradiol gave only minimal changes of the lipoproteins.
The lipoprotein changes observed during treatment with oral oestradiol might reduce the risk for atherosclerotic disease. Therefore, from a lipoprotein point of view, oral oestradiol treatment probably could be considered beneficial. The cutaneous oestradiol treatment had comparable clinical effects without any influence on the lipoprotein pattern.
Relationship of follicle stimulating hormone (FSH)-sensitive adenylate cyclase activity to FSH binding in immature rat ovaries following administration of pregnant mare serum gonadotrophin
Authors: Lee C. Y. , Reichert L. E. 
Published: December 2008

Abstract.
The time and dose-response relationships of human follicle stimulating hormone (hFSH)-sensitive adenylate cyclase activity to hFSH binding was studied in the immature rat ovary following an sc injection of pregnant mare serum gonadotrophin (PMSG). When an optimal dose of PMSG (10 IU/rat) was administered, a marked increase in hFSH-sensitive activity was observed at day 2, followed by a sharp decline at day 3. This was accompanied by a parallel rise and fall in ovarian hFSH binding activity. When immature rats were given various doses (5–100 IU/rat) of PMSG for 2 days, hFSH-sensitive adenylate cyclase activity increased sharply and maximal stimulation was obtained at 10 IU/rat. A close correlation was also observed with respect to dose-response for hCG-sensitive adenylate cyclase and hCG binding activities. It is concluded that: 1) PMSG administration with an optimal dose to the immature rat induced ovarian FSH and LH-hCG receptors, and an adenylate cyclase system highly sensitive to hFSH and hCG, and 2) the acquisition and responsiveness of adenylate cylcase to gonadotrophins are closely related to the appearance and the numbers of gonadotrophin receptors.
Long-term treatment of osteoporosis with 24,25 dihydroxycholecalciferol
Authors: Reeve J. , Tellez M. , Green J. R. , Hesp R. , Elsasser U. , Wootton R. , Hulme P. , Williams D. , Kanis J. A. , Russell R. G. G. , Mawer E. B. , Meunier P. J. 
Published: December 2008

Abstract.
Five patients with involutional osteoporosis were treated with 24,25 dihydroxycholecalciferol (24,25-(OH)2D3) for 6 months, in doses sufficient to double plasma levels at that time. Dietary calcium absorption transiently improved by nearly 2 mmol Ca per day at 2 weeks, but this effect was lost by 6 months. The calcium and phosphate balances followed the trends in calcium absorption. Only twenty-five dihydroxyvitamin D levels changed little. Histomorphometric and kinetic indices of new bone formation and bone blood flow remained stable but there was an increase in urine hydroxyproline at 6 months, which was of borderline statistical significance. Treatment at this dosage of 24,25(OH)2D3, which increased plasma levels within the physiological range, conferred no measurable long-term benefit on our patients. Larger doses, or combination therapy, may warrant further clinical evaluation in osteoporosis.
The possible prognostic value of serum prolactin increment during pregnancy in hyperprolactinaemic patients
Authors: Andersen A. Nyboe , Starup J. , Tabor Ann , Jensen H. Kålund , Westergaard j. G. 
Published: December 2008

Abstract.
In 15 hyperprolactinaemic, infertile patients achieving 17 bromocriptine-induced pregnancies, the presence or absence of prolactin (Prl) increment in the 3rd trimester of pregnancy was correlated to the basal Prl levels before treatment and after pregnancy. The hyperprolactinaemic patients revealed a marked heterogeneity in the Prl increment compared to normal women. Five patients showed a pronounced increase in serum Prl during gestation, whereas Prl levels were unaltered or decreased slightly in 10 patients. In the latter group of patients serum Prl was significantly (P<0.01) lower after pregnancy than before treatment.
Our study indicates that some hyperprolactinaemic patients may benefit from a pregnancy, and that these patients probably can be identified, as they do not show any significant changes in Prl levels during pregnancy.
Human growth hormone blunts Na2EDTA-induced hypocalcaemia in hyposomatotrophic children
Authors: Root Allen W. , Duckett Gregory E. , Sweetland Margaret , Livingston Catherine , Reiter Edward O. 
Published: December 2008

Abstract.
An infusion of disodium ethylenediamine tetraacetate (Na2EDTA) (0.13 mmol/kg for 2 h) was administered to 10 hyposomatotrophic children prior to and after 6 and 12 months of treatment with human growth hormone (hGH). Total and ionized calcium and immunoreactive parathyroid hormone (iPTH) concentrations were determined. Mean basal total and ionized calcium concentrations did not change during the year of treatment with hGH. The nadir concentrations of total and ionized calcium increased progressively during hGH administration and after 12 months were significantly increased over pre-treatment values (total calcium: pre-treatment 1.85 ± 0.32 (sd) mmol/l, + 12 months 2.10 ± 0.15, P < 0.01; ionized calcium: pre-treatment 0.55 ± 0.31 mmol/l, + 12 months 0.78 ± 0.14, P < 0.05). The mean basal concentration of iPTH increased slightly after 12 months of hGH administration (pre-treatment 72 ± 18 pg/ml, + 12 months 106 ± 71, P < 0.05), but Na2EDTA-evoked secretion of iPTH was not significant altered by hGH.
Interaction of gastric inhibitory polypeptide (GIP) and cholecystokinin (CCK-8) with basal and stimulated insulin secretion in mice
Authors: Ahrén Bo , Hedner Pavo , Lundquist Ingmar 
Published: December 2008

Abstract.
The interaction of GIP and CCK-8 with basal insulin secretion and with insulin release induced by glucose or by the β-adrenoceptor agonist l-isopropylnoradrenaline (l-IPNA) was studied in mice.
GIP and CCK-8, when injected in threshold doses not affecting basal insulin secretion, did markedly enhance basal insulin release when given simultaneously. Maximal doses of the two peptides, on the other hand, did not potentiate each other's action, but displayed a pure additive effect on insulin secretion.
Insulin release induced by a half-maximal dose of glucose was slightly potentiated by the threshold dose of GIP and markedly potentiated by the maximal dose i.e. the effect was greater than the algebraic sum of the individual actions. CCK-8 was without potentiating effect at both dose levels. The combination of GIP and CCK-8 did not display the potentiating effect of GIP alone on glucose-stimulated insulin release. However, an additive action was observed at both dose levels.
Insulin release stimulated by a half-maximal dose of l-IPNA was not affected by either GIP or CCK-8 at the threshold doses. The combination of the two peptides and l-IPNA, however, displayed a lower response than that expected from an additive effect. Similarly, at the high dose level of the peptides, the combination of GIP plus CCK-8 and l-IPNA as well as CCK-8 alone plus l-IPNA displayed a lower insulin response than that expected from an additive effect. GIP alone plus l-IPNA gave the expected additive effect.
The results show that interactions between different gastrointestinal polypeptides with insulin release may greatly change the expected effect exerted by any individually tested peptide, and that the action of the peptides on stimulated insulin secretion is highly dependent on the nature of the secretagogue. Such complex interactions must be borne in mind in the search for the incretin factor(s).
Effects of various replacement oestrogens on hepatic transcortin synthesis in climacteric women
Authors: Schwartz Ulf , Volger Heide , Schneller Eberhard , Moltz Lothar , Hammerstein Jürgen 
Published: December 2008

Abstract.
The influence of peri-menopausal oestrogen replacement therapy upon protein synthesis in the liver was investigated. Changes in the cortisol-binding capacity of transcortin (TC-BC) were utilized as an indicator of hepatic oestrogen sensitivity. Forty-two climacteric women were studied before and after treatment with various drugs at different doses (patients receiving identical compounds served as their own controls for the evaluation of dosage effects; duration of medication: 14 days at each dose). Oral administration of oestriol (1 and 2 mg daily; n = 6), oestriol (1 and 2 mg daily) + oestradiol-17β (2 and 4 mg daily; n = 8), oestradiol valerate (1, 2, 4 and 6 mg daily; n = 6), conjugated equine oestrogens (0.3 and 0.6 mg daily; n = 6), sodium oestrone sulphate (0.8 and 1.6 mg daily) + sodium equilin sulphate (0.2 and 0.4 mg daily; n = 6) and quinoestrol (25 μg daily; n = 6) failed to alter TC-BC. However, ingestion of higher doses of conjugated equine oestrogens (0.9 and 1.25 mg daily; n = 5) and quinoestrol (50 μg daily; n = 6) caused a significant rise (P < 0.01). Ethinyloestradiol was given orally as a reference substance and elicited an elevation of expected magnitude. Vaginal administration of dienoestrol cream (1 mg daily; n = 4) did not change TC-BC. These data indicate that the hepatotrophic effects of replacement oestrogens vary depending on the preparation and dosage selected for treatment.
Is the adrenal angiotensin receptor angiotensin II — or angiotensin III like?
Authors: Braley Lynne M. , Menachery Alphonsa I. , Underwood Richard H. , Williams Gordon H. 
Published: December 2008

Abstract.
In order to determine whether the adrenal receptor is primarily directed at angiotensin II (All) or angiotensin III (AIII) the following in vitro experiments were performed examining aldosterone responsiveness in isolated glomerulosa cells. 1) Cells exposed to increasing doses (2.4 × 10−10 m – 2.4 × 10−6 m) of All or AIII were found to be significantly more responsive to All (All's ED50 was 6.3 × 10−10 m vs AIII's 4.6 × 10−9m P < 0.001). 2) Octapeptide analogues (Sar1 Ala8 and Asn1 Ala8), while demonstrating different inhibitory potencies relative to each other, were equally effective in blocking All vs AIII stimulation. 3) The heptapeptide analogues (des1 Ala8 and des1 Ile8) however, inhibited AIII stimulation preferentially (P < 0.01). 4) The 8 alanine octapeptide analogues were better inhibitors of both All and AIII stimulation than the 8 alanine heptapeptide analogue. 5) HPLC analysis indicated that All and AIII were being degraded at the same rate during the incubation procedure.
These results, taken together, strongly suggest that the angiotensin adrenal receptor is an All receptor.
Basal and TRH stimulated serum levels of TSH in patients with hyperprolactinaemia and in subjects on oestrogen treatment
Authors: Erfurth Eva M. , Hedner Pavo , Nilsson Anders 
Published: December 2008

Abstract.
In 21 hyperprolactinaemic patients without other signs of pituitary dysfunction the mean basal serum level of TSH was 4.4 ± 0.47 μU/ml that was significantly (P < 0.001) higher than controls (2.5 ± 0.16 μU/ml and oestrogen treated individuals (2.4 ± 0.29 μU/ml). The TSH increase was more pronounced (P < 0.05) in hyperprolactinaemic patients without sellar enlargement and with moderately elevated plasma prolactin levels (155 ± 42 μg/ml) than in patients with sellar enlargement and higher plasma prolactin levels (857 ± 306 μg/ml). The serum levels of thyroxine and triiodothyronine in the hyperprolactinaemic patients did not differ significantly from controls. Patients with thyroid antibodies were excluded. The increased basal serum level of TSH in hyperprolactinaemia is compatible with the concept of a reduced dopaminergic tonus as the mechanism for both changes. In patients with advanced hyperprolactinaemia and sellar enlargement the high prolactin level may induce some inhibition of TSH release and explain their lower basal serum level of TSH that was probably not due to pituitary compression as they responded normally to TRH.
The TSH response to TRH was significantly (P < 0.05) correlated to the basal serum TSH in all groups. The regression lines were very similar for hyperprolactinaemic patients and controls suggesting that in hyperprolactinaemia the thyrotroph has not changed its mode of response to TRH. In contrast, oestrogen treated subjects in addition to dependence on basal serum TSH levels showed a genuinely augmented response to TRH (164.6 ± 20.3%, P < 0.01) compared to controls.