The hyperglycaemic effect of s-nitroso-glutathione via the release of nitric oxide - abstract

ABSTRACT

Recent evidence suggests that nitric oxide (NO) is an important factor in both inflammatory-induced and streptozotocin-induced diabetes. In this study we investigated the pharmacological activity of S-nitroso-glutathoine (GNSO), a carrier of NO, on blood glucose level in 10 mongrel dogs, and measured their plasma nitrate concentration after the administration of GSNO. S-nitroso-glutathoine elicited a dose-dependent increase in blood glucose level (15 - 102 percent) which was paralled with an increase in nitrate production. The blood glucose levels at 2.0 and 2.5 hrs in an Oral Glucose Tolerance Test were significantly higher in dogs administered with GNSO than those of the controls (p<0.05). There was also a significant increase in plasma nitrate on administration of GSNO (35 - 100 percent). The plasma nitrate concentrations from 0.5hr to 2.5hrs were significantly higher compared to the controls (p<0.05). The hyperglycaemic effect of GSNO was enhanced with the co-adminstration of ascorbic acid. This resulted in 5 - 30 percent increase in blood glucose concentration. The blood glucose levels at 2hrs in dogs after the co-administration of 35mg kg of GSNO (P<0.05). The data from this study showed that persistent hyperglycemia can be an unwanted side effect of GSNO administration and that the glucose concentration should be closely monitored when this drug is used to treat patients(AU)