Hypoglycemic therapy and hemostasis in maturity- onset diabetes mellitus: existence of an early prethrombotic state

Effect of PHA-B fraction of Agaricus bisporus lectin on insulin release and 45Ca2+ uptake by islets of Langerhans in vitro

The effect of a purified PHA-B fraction of Agaricus bisporus lectin on insulin release and 45Ca2+ uptake by islets of Langerhans was studied. It was found that at 2 mM glucose +17.5 micrograms/ml A. bisporus PHA-B (which produces half-maximal stimulation) there was a 3.3 fold increase in insulin secretion as compared to controls (2 mM glucose). Stimulation of insulin release was found to be dose-related as well as time-dependent. Maximal stimulation of insulin release was obtained at a lectin concentration of about 60 micrograms/ml and proceeded as a linear function of time for about 1 h. It was found that in the presence of 2 mM glucose +17.5 micrograms/ml lectin islet 45Ca2+ uptake was enhanced more than 11-fold as compared to controls. 45Ca2+ uptake was found to be lectin dose- and time-dependent and maximal uptake was achieved at a lectin concentration of about 60 micrograms/ml after which the rate slowed down until it reached a stationary phase at about 75 micrograms/ml.

Hypoglycemic treatments and the fibrinolytic system in maturity-onset diabetes mellitus without thromboembolic manifestations

The fibrinolytic system was investigated in 115 patients with maturity-onset diabetes mellitus in good metabolic control and without thromboembolic manifestations. The patients were divided into 7 groups according to the hypoglycemic therapy: diet alone, tolbutamide, glibenclamide, phenformin, combination of the last two drugs, insulin, combination of insulin and phenformin. Our results indicate that in maturity-onset diabetes both fibrinolytic activity and inhibitors of fibrinolysis are increased. The enhanced fibrinolytic activity was not affected by different hypoglycemic drugs, whereas the main antiplasmins showed wide variations in the different treatment groups. In particular, a significant reduction of alpha 2M was observed in patients on glibenclamide therapy. In conclusion, our study showed that the high fibrinolytic state seems to be a constant element in diabetes, and that the different behaviors of the fibrinolytic system, reported by various authors in patients taking different hypoglycemic drugs, could be explained by the wide range of plasmin inhibitor levels observed in these conditions.