Short- and long-term gliclazide effects on pancreatic islet cell function and hepatic insulin extraction in non-insulin-dependent diabetes mellitus.

Nine non-obese males with non-insulin-dependent diabetes mellitus (NIDDM) were evaluated before and after 3 and 12 months (6 patients) treatment with the second generation hypoglycemic sulfonylurea: gliclazide. They underwent an oral glucose tolerance test, intravenous glucose and arginine tests measuring plasma insulin and C-peptide responses. Pre-hepatic insulin production and insulin delivery to peripheral tissues were calculated by deconvolution techniques and hepatic extraction of insulin estimated. An improvement was observed in the beta-cell function of the patients on gliclazide treatment: reduction of fasting plasma glucose associated with a progressive increase in C-peptide level but insulin levels decreased at 12 months, suggesting an increase in hepatic insulin extraction at this time. In the same way, while plasma glucose values after oral and i.v. glucose were greatly reduced at 3 and 12 months treatment, insulin did not change but C-peptide levels increased significantly at 12 month treatment. While the prehepatic insulin secretion rate increased progressively on gliclazide during all glucose challenges, the fractional hepatic insulin extraction fell after 3 and increased at 12 month treatment, with opposite changes in insulin delivered to peripheral tissues. Thus the insulinogenic effect of gliclazide could be masked during long-term administration by a concomitant effect of gliclazide which increases hepatic extraction of insulin. The maintenance of the responsiveness to the non-glucose secretagogue, arginine, as evaluated by the C-peptide levels, before and after correction of hyperglycemia, suggested improvement of beta-cell sensitivity to glucose after sulfonylurea treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of the subacute effects of a new glucocorticoid, deflazacort, and prednisone on the hypothalamic-pituitary-adrenal axis of normal subjects.

The effects of deflazacort (DFL), a new oxazoline derivative of prednisolone, were compared with those of prednisone (Pd) by measuring plasma cortisol (F) levels as an index of the function of the hypothalamic-pituitary-adrenal (HPA) axis. Twelve normal volunteers received each glucocorticoid for 16 to 24 days in a double-blind cross-over trial with random allocation of subjects to treatment with DFL (24 mg/day) and Pd (20 mg/day) in clinically equivalent doses, with a washout period from 20 to 45 days between administration of the glucocorticoids. The following tests were performed in a randomized sequence: cortisol (F) circadian rhythm, insulin tolerance test (ITT), lysine-vasopressin (LVP) and B1-24 ACTH stimulation. Despite basal F suppression by DFL, the relative maximum F response (maximum F increment above basal/basal x 100) was significantly greater than control for the ITT and ACTH tests and was similar to the control after intramuscular injection of LVP, suggesting that the responses were appropriate for the basal F levels, with the HPA being reset at a lower level. After Pd, despite higher basal F levels, the F diurnal rhythm disappeared and there was no significant response to ITT, LVP or ACTH, indicating that the limiting factor in the HPA response was the reduced adrenal F production independent of the effects on the steroid-sensitive tissues of the brain including the pituitary.

Stability of freeze-dried glucagon for tracer preparations.

A propriedade de glucagon seco por congelamento para a radioiodinacao foi avaliada durante periodo de ate 21 meses para armazenamento a - 20oC. Nesse periodo, alteracoes nos hormonios purificados rotulados e nao rotulados foram analisados por eletroforese com gel de poliacrilamida. A reatividade imunologica do tracejador tambem foi observada num sistema de radioimunoensaio. Os resultados obtidos indicaram que ate o nono mes de estocagem o glucagon permanece inalterado. Depois de 20 meses a molecula de glucagon se mostrou alterada, com correspondente perda da imunorreatividade