摘要:

Several parameters of thyroid function were studied in 112 non-ketoacidotic youngsters with insulin-dependent diabetes mellitus (IDDM). Levels of thyroxine (T4), reverse triiodothyronine (rT3), thyroxine-binding globulin (TBG) and T3 were lower than in controls, whereas FT4, and FT3 were normal. T4 levels in IDDM patients were positively related to T3, rT3 and TBG, and inversely related to haemoglobin Ai (HbA1. However, only 4 patients showed biochemical hypothyroidism (T4 < 5 µg/100 ml), whereas their FT4, FT3 and thyroid-stimulating hormone (TSH) levels were normal. Concurrent variations of T3 and rT3 levels were found in IDDM patients; thus, their T3/rT3 ratios were stable or higher than in controls, indicating that peripheral deiodination of T4 is preferentially oriented to production of rT3 only during ketoacidosis. Although changes in thyroid function may reflect the degree of metabolic control of diabetes in a large population, the clinical usefulness of serum thyroid hormone measurements in an individual case still appears to be limited

ISSN:1663-2818    

DOI:10.1159/000179999

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

The present report describes a mother and 2 children with leucine-induced hypoglycemia (LIH). Hypoglycemic episodes following high-protein meals first appeared at age 4–7 months. Leucine-stimulation tests triggered marked hyperinsulinism and hypoglycemia in the children and a milder but abnormal response in the mother. To evaluate the therapeutic effects and to study the mechanism of hyperinsulinism in LIH, the leucine test was repeated under treatment with diphenylhydantoin, oxprenolol (a beta-blocker), and diazoxide. Diazoxide abolished hyperinsulinism; diphenylhydantoin did not affect the response to leucine; and oxprenolol, tested in the mother only, increased hyperinsulinism and hypoglycemia. Our results indicate that LIH is an autosomal dominant disorder; LIH may persist into adulthood with milder clinical symptoms and chemical response to leucine; diazoxide is the treatment of choice in LIH. Considering the effects of the three agents on stimulated release of insulin, it is concluded that leucine triggers hyperinsulinism by a mechanism different from that of glucose and beta-adrenergic receptor

ISSN:1663-2818    

DOI:10.1159/000180000

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

Plasma estradiol (E2), serum LH and FSH, and the gonadotropin response to two consecutive LHRH administrations (10 and 100 µg with an interval of 2 h) were determined in 19 patients with anorexia nervosa (AN) at the emaciation phase, before and after estradiol benzoate (E2B) injections (3 µg/kg/day for 7 days). The same investigations were repeated after weight restoration in 9 AN atients who remained amenorrheic. Both at the emaciation phase and after weight restoration, E2B enhanced the second LH response to LHRH and decreased serum FSH, suggesting that the functional capacities of the pituitary gonadotrophs are normal in AN. Unlike E2B injections, weight restoration increased all the hormone values, suggesting that the weight restoration effects on the abnormal gonadotropin secretory pattern of AN depend on another mechanism than the E2 lowering. That mechanism is probably a disorder of the hypothalamic LHRH secretion, the consequences of which could be reinforced by the low E2 level

ISSN:1663-2818    

DOI:10.1159/000180001

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

A ‘normal range’ for salivary progesterone concentrations has been established using data derived from women who were menstruating regularly and in whom dating of the cycle by accepted criteria was possible. Since these values are in agreement with those in the first 9 days of conception cycles and with those in cycles in which ovulation was confirmed by ultrasonography, they provide a reliable index of progesterone output compatible with fertility. Measurement of daily salivary progesterone values in subfertile women for time spans exceeding 3 months allowed accurate assessment of base-line ovarian activity and of the response to ovulation-induction therapy. Salivary sampling, by allowing collection of frequent samples with a minimum of time, stress and inconvenience, is ideally suited to longitudinal studies of ovarian activity. This sampling regimen is also applicable to the monitoring of progesterone output throughout pregna

ISSN:1663-2818    

DOI:10.1159/000180002

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

The effects of acute and chronic stress on serum corticosterone and pituitary-thyroid hormones were studied in male Wistar rats. Acute noise activated both the pituitary-adrenal and pituitary-thyroid axes. Chronic noise did not modify the basal serum levels of either corticosterone or pituitary-thyroid hormones. A decreased corticosterone response to noise was observed in chronically stressed rats, but the pituitary-thyroid response was the same in control and chronically stressed rats, suggesting that the mechanisms which control the responsiveness of both axes to a repeated stimulus are dissociated.

ISSN:1663-2818    

DOI:10.1159/000180003

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

Cultured neoplastic cell lines are widely considered an adequate model for insulin receptor studies. In this work the insulin receptor of a well-known continuous T-cell line (MOLT 4) was characterized. These cells showed specific insulin receptor with binding properties quite similar to those of other lymphoblastoid cells. Therefore, we used MOLT 4 receptor to evaluate the effect of the sulfonylurea glipizide on insulin binding. After a 24-hour preliminary incubation of cells with glipizide, we found a 44% increase of insulin receptor binding apparently due to an increase of insulin binding sites.

ISSN:1663-2818    

DOI:10.1159/000180004

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

Prolactin, alone and in combination with ACTH, was tested for its ability to release steroids from rat adrenocortical slices superfused in vitro. The hormone possessed weak activity alone (minimal responsive dose = 1 U), but was able to potentiate the ACTH-stimulated corticoid release at much lower doses (significant response over ACTH alone at 0.01 U prolactin). This latter dosage was calculated to be within the physiologic range of prolactin in blood. Analysis of individual steroids in superfusate by RIA revealed that aldosterone release was most sensitive to prolactin, followed by corticosterone, androstenedione, and progesterone. We conclude that prolactin is an adrenocortical secretagogue of physiological relevance in the rat, and that it could play a role in enhancing the action of ACTH to acutely release steroids.

ISSN:1663-2818    

DOI:10.1159/000180005

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

In dams which had been kept isolated from pups for 8–10 h, the magnitude of the suckling-induced prolactin rise in the plasma was studied in relation to intensity of suckling stimulus and lactational age of the mother. At midlactation the response of prolactin evoked by suckling was enhanced as litter size increased. Suckling of 2 pups induced a greater prolactin rise in dams adjusted to 2 pups than in dams adjusted to 8 pups. Suckling of 8 pups caused a greater prolactin rise in dams which had been adjusted to an 8-pup litter, than in rats with a 2-pup litter. At late and prolonged lactation the rise of prolactin in the plasma induced by the suckling stimulus of 8 pups was significantly lower than at midlactation. Injection of perphenazine after a period of suckling induced a moderate increase of plasma prolactin in dams at midlactation, and a similar increase in dams at late lactation and at day 42 of lactation. It is concluded that in the first half of lactation the number of pups, i.e. the intensity of the suckling stimulus, is an important factor in determining the magnitude of the prolactin response to suckling. The lower response of plasma prolactin to suckling in late lactation is neither caused by a decrease in suckling stimulus from the pups nor by an increase in prolactin clearance; it is probably due to a gradual reduction in prolactin synthesizing and releasing capacity of the pituitary, brought on by a desensitization of the neural or neuroendocrine system to suckling stimuli as lactation proceed

ISSN:1663-2818    

DOI:10.1159/000180006

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

The previously reported refractoriness of pituitary response to thyrotropin-releasing hormone (TRH) stimuli was investigated here in an in vitro perfusion system using pituitary tissue from euthyroid and hypothyroid rats. Thyroid-stimulating hormone (TSH) and prolactin (PRL) responses to TRH (28 pmol) were significantly greater in hypothyroid tissue compared with euthyroid. Hypothyroid tissue showed a reduction in response to two consecutive stimuli in both TSH and PRL, however the TSH decline in response was more marked than PRL. Euthyroid tissue showed no significant decline in response to TRH. An increase in the dose of TRH (112 pmol), administered to euthyroid tissue, resulted in increased TSH and PRL response, but no decline in response to sequential stimuli was observed. Three consecutive stimuli by TRH (28 pmol) of hypothyroid tissue resulted in a consistent decline in TSH response. The decline in PRL response only reached statistical significance by the third stimulation. Euthyroid and hypothyroid pituitary tissue was subjected to sequential depolarising stimulation with KCl (50 µmol). Euthyroid tissue showed no decline in response in either TSH or PRL. In hypothyroid tissue only, the decline in TSH response reached statistical significance. This decline in TSH response was significantly smaller than the decline in response observed in hypothyroid tissue stimulated with TRH. Refractoriness of hypothyroid pituitary tissue to repeated TRH stimuli is reported here. Our data suggest that the decline in hormonal response cannot be explained solely on the basis of tissue depletion

ISSN:1663-2818    

DOI:10.1159/000180007

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

Matrex gel red A purified follicular fluid has been used to study whether or not this material contains sialic acid residues and their importance in maintaining the biological activity of inhibin both in vitro and in vivo. It appears that sialic acid is present in these preparations and can be released either by neuraminidase treatment of acid hydrolysis. The addition of intact and desialylated inhibin-containing material to isolated rat pituitary cells in culture gives similar inhibition of LHRH-induced FSH release of these cells indicating that sialic acid is not required for inhibin activity in vitro. The injection of intact inhibin preparations leads to a reduction of the uterine weight increase seen in immature female mice primed with human chorionic gonadotropin. By contrast, the inhibition of this uterine weight increment by 80% desialylated inhibin-containing material is significantly reduced, suggesting that sialic acid residues play an important role in maintaining the biological activity of inhibin in vivo.

ISSN:1663-2818    

DOI:10.1159/000180008

出版商:S. Karger AG    

年代:1984

数据来源: Karger