摘要:

SUMMARYThe acute administration of 2 mg of methysergide significantly reduced plasma prolactin levels in nine normal subjects and in seven hyperprolactinaemic patients. The prolactin lowering effect of this drug was abolished by sulpiride. Moreover methysergide lowered plasma GH levels in four out of nine acromegalic patients, who were also responsive to a dopaminergic drug such as bromocriptine. Although methysergide did not significantly blunt the TRH‐induced prolactin release, our data suggest that this drug may affect GH and prolactin release through a dopaminergic mechanism of action. This effect should be taken into account when methysergide is employed as antiserotoninergic drug in neuroendocrinological studie

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1977.tb01325.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYTwelve acromegalic patients were studied in one or more of three protocols to establish the response of plasma growth hormone (hGH) concentrations to (a) a single oral test dose of bromocriptine, (b) incremental dose therapy from 10 mg/day to 40 mg/day over 4 weeks, and (c) sustained therapy with 20 mg/day over a 3 month period. Ten of the patients studied had previously been treated by yttrium implantation, external pituitary irradiation or surgical hypophysectomy. A high incidence of side effects including postural hypotension, hallucinations and peripheral vasospasm was noted reducing the numbers of patients completing the three protocols. Suppression of hGH concentrations was disappointing; significant reductions in hGH concentrations occurred in five of eleven patients in response to a single test dose of bromocriptine, and in only one of seven patients treated with the drug over a sustained period. An impression of clinical improvement was gained in one patient, but there was no associated reduction in plasma hGH concentrations. It seems likely that acromegalic patients who have failed to respond to conventional treatment may be more resistant to bromocriptine therapy.

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1977.tb01326.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYSeven normal male volunteers were given a 2 h intravenous infusion of insulin (2 mu kg‐1min‐1). During the first hour, in which normoglycaemia was maintained by glucose infusion, no detectable increase in growth hormone (GH) secretion occurred. When controlled symptomatic hypoglycaemia was produced during the second hour of the insulin infusion a brisk rise in plasma GH concentration was observed in all the subjects studied. Since it was possible that the falls in the concentration of plasma free fatty acids (FFA) occurring during infusion of insulin also acted as a stimulus to GH release the study was repeated in four subjects but normoglycaemia was maintained throughout the entire 2 h period of insulin infusion. In these experiments there was no rise in plasma GH concentration although a similar fall in plasma FFA was produced. These results clearly indicate that hypoglycaemiaper sewas the important stimulus to GH secretion and not hyperinsulinaemia or a lowering of plasma FFA. Furthermore there appeared to be a threshold hypoglycaemic stimulus to GH secretion. In no subject was a rise in plasma GH seen without a fall in plasma glucose greater than 1.4 mmol/l. Prolonged mild hypoglycaemia did not stimulate GH secret

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1977.tb01327.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYThyroid function was studied in thirty‐five euthyroid geriatric inpatients to define the relative importance of T4 to T3 conversion or pituitary‐thyroid dysfunction as a cause of low serum T3 concentrations. A previously reported finding of low serum total T3 levels was confirmed, and was associated with a fall in mean unbound T3 to 5.23 pmol/l (6.70 in younger normal subjects) and a rise in unbound T4 to 52.7 pmol/l (36.4 in normals). However, the protein binding of T3 and T4 was weaker in the patients (e.g. per cent unbound T4 increased 1.4 times) despite a mean increase in serum immunoreactive TBG concentration of 30%. Mean serum reverse T3 concentration (rT3) was nearly doubled in the patients (0.42 nmol/l compared with 0.24 in normals) but the correlation between high rT3 and low T3 was not close, and in a fifth of patients low T3 was not associated with high rT3. The T3 response to TSH injection was greater in patients with low T3 levels, and the T4 response smaller. The overall effect of TSH injection was to restore the previously increased T4 to T3 ratio of the patients to normal. The TSH response to TRH was absent in about a third of patients, and delayed in about another quarter, especially, although not exclusively so, in patients with low serum T3. The data suggest that several factors are concerned in the pathogenesis of low serum T3 concentrations in the elderly in hospital. Among these may be a shift in T4 deiodination from T3 to rT3, and hypothalamo‐pituitary TSH dysfunction. But it appears that other undefined factors may be responsible (such as nutrition or steroid levels); the pathogenesis is probably not the same in all pat

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1977.tb01328.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYDiurnal plasma insulin and glucose concentrations were studied in six diabetic patients, each treated with five different insulin regimes. Subcutaneous soluble insulin was too slow and long acting for physiological replacement of the normal insulin response to meals, but the peak insulin levels were higher than the postprandial levels of normal subjects. Intramuscular insulin, though absorbed more quickly than subcutaneous insulin, was not clinically advantageous. Three rather than two injections of soluble insulin gave improved blood glucose control but two combined injections of short and medium acting insulins gave nearly as good results. A long acting insulin was needed to prevent raised plasma glucose levels overnight.

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1977.tb01329.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARYA theoretical model is proposed which describes the binding of thyroid hormones to serum proteins in terms of easily determined parameters. Not only free hormone concentration but also the distribution of hormone among various binding sites may be computed. The mathematical approach is capable of dealing with models of differing complexity of binding from simple‘one binding site per protein molecule’systems to those involving‘negative co‐operativity'. The approach gives predictions of thyroid function parameters which are in good agreement with those observed in p

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1977.tb01330.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1977.tb01331.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SUMMARY. Using a previously described radioimmunoassay for growth hormone release inhibiting hormone (GH‐RIH), the presence of GH‐RIH‐like immunoreactivity in urine has been characterized by demonstrating mobility identical to synthetic GH‐RIH standard on two sephadex gel chromatographic systems, and parallelism of dilutions of the sephadex fractions with synthetic GH‐RIH. Furthermore, 74% of the sephadex fraction cross‐reacting in the immunoassay bound to antibody conjugated to sepharose and could be eluted by 1 M acetic acid. This immunospecific eluate showed identity with synthetic GH‐RIH on both ion exchange and thin layer chromatography. Thus GH‐RIH‐like immunoreactivity is present in normal urine; this may have potential relevance in the search for a physiological role

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1977.tb01332.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

Book Review in this ArticleCongenital Adrenal Hyperplasia.Ed. by P. A. LEE, L. P. PLOTNICK, A. AVINEA KOWARSKI and C. J. MIGEONProlactinBy D. F. HORROBINHuman Semen and Fertility Regulation in Men.Ed. by E. S. H. HAFEZ.The Fetus and BirthEssays in Neurochemistry and Neuropharmacology. Ed. by M. B. H. YOUDIM, W. LOVENBERG, D. F. SHAMAN and J. R. LAGNADO

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1977.tb01333.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

ISSN:0300-0664    

DOI:10.1111/j.1365-2265.1977.tb01334.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY