Reduction in blood and urine glucose levels in streptozotocin and alloxan diabetes by phenazine methosulfate

The purpose of this investigation was to ascertain the ability of phenazine methosulfate (PMS) to improve the streptozotocin (STZ) and alloxan induced diabetic condition in vivo as determined by changes in blood and urine glucose levels and by alteration in the secretion of insulin by isolated islets. STZ and alloxan diabetes was induced in male albino rats (200-250 g body weight). A single injection of PMS (6.0 mg/kg) or nicotinamide (500 mg/kg) simultaneously with diabetic doses of either STZ or alloxan caused a significant reduction in blood and urine glucose levels three days after the injection. The reduction in glycemic levels was greater with PMS than with nicotinamide. Daily PMS (0.5 mg/kg) injection, initiated 5, 10, 20 or 30 days after the development of STZ- and alloxan-diabetes, caused a significant decrease in blood and urine glucose levels and also increased body weight determined 60 days after STZ or alloxan administration. These effects were observed even if the injections were initiated 20 or 30 days after the onset of the diabetic syndrome. Glucose stimulated insulin secretion was significantly inhibited by pre-incubation of isolated islets for one hour at 37 degrees C with either STZ or alloxan. However, insulin secretion was induced by PMS in the STZ or alloxan pretreated islets. Nicotinamide neither protected nor induced insulin secretion under similar conditions. The level of insulin secretion induced by PMS whether in the normal islets or in islets previously exposed to the B-cytotoxic agents were comparable in quantity to glucose (17 mM)-stimulated insulin secretion.