RESTRICTED EFFECT OF FORMYCIN-A AND NON-GLUCIDIC NUTRIENTS UPON INSULIN RELEASE IN ISLETS FROM RATS WITH HEREDITARY OR ACQUIRED NON-INSULIN-DEPENDENT DIABETES

Pancreatic islets isolated from control rats, Goto-Kakizaki rats and adult rats that were injected with streptozotocin during the neonatal period were incubated for two successive periods of 90 min each in the presence of D-glucose (11.1 mM) with or without formycin A (1.0 mM), and in the presence of the dimethyl ester of succinic acid (SAD, 10.0 mM) with or without palmitate (1.0 mM). Although formycin A augmented glucose-stimulated insulin release in both control and diabetic rats, it failed to compensate for the impaired secretory response to D-glucose in the latter animals. Likewise, non-glucidic nutrients such as SAD and/or palmitate failed to display a more efficient insulinotropic action, relative to basal insulin output, in diabetic than control rats. These results indicate that both formycin A and non-glucidic nutrients are unable, through their immediate insulinotropic action, to restore a normal output of insulin in islets of animals with inherited or acquired non-insulin-dependent diabetes.