ABSTRACT
Eighty adult male albino rats of local strain with average weight of 220 gm were used to investigate the effect of insulin and/or oral hypoglycaemic drugs on serum glucose, total triglycerides, total cholesterol, high density lipoptotein cholesterol [HDL-chol], and low density lipoprotein cholesterol [LDL-chol] levels. The animals became diabetic by intraperitoneal injection of a lonely dose of streptozotocin. Except the control normal and control diabetic non-treated groups, all other six groups were subjected to different lines of treatment of oral sulfonylurea hypoglycaemic agent [glibenclamide], biguanide hypoglycaemic agent [metformin] and subcutaneous protamine zinc insulin. It was found that diabetic non-treated group showed higher serum glucose, triglycerides, total cholesterol and [LDL-chol] levels. On the other hand, [HDL-chol] level was lower as compared with the control group. Treatment with the above mentioned hypoglycaemics, alone and in combination, reduced serum glucose, triglycerides, total cholesterol, and LDL-chol, while HDL-chol increased to some extent. This effect may be explained by the fact that streptozotocin destroys the pancreatic beta cells, so glibenclamide loses its main action on beta cells completely and acts only by its peripheral mechanism. On the other hand, metformin caused significant reduction in serum glucose and lipid profile possibly because its main action is insulin independent. It was found that the addition of either glibenclamide or metformin to insulin treatment improved and prolonged its effect on these criteria