The effect of metformin and exercise on serum lipids, nitric oxide synthase and liver nitric oxide levels in streptozotocin-nicotinamide induced diabetic rats

Abstract

The objective of this study was to determine the effects of metformin treatment and exercise intervention on lipid metabolism, nitric oxide (NO), nitric oxide synthase (NOS) and glucose levels in streptozotocin-nicotinamide (STZ-NA) induced diabetic rats. Male wistar rats were used to conduct the study and they were divided into five groups of 8 rats in each. These groups are: Control group, diabetes group (STZ-NA), diabetes and metformin (DMet) group, diabetes and exercise (DE) group, and diabetes + exercise + metformin (DEMet) group. The STZ-NA induced diabetic rats were used as a model of type 2 diabetes. Metformin was orally administered to rats. For exercise intervention, rats were forced to run in a running wheel for 10 min each day (20 m/min/day). At the end of experimental period, blood glucose, glycated hemoglobin (HbA1c) levels, plasma lecithin:cholesterol acyltransferase (LCAT) levels, serum triglyceride (TG), cholesterol, high density lipoprotein (HDL), Apo A-I, NOS and liver NO levels were determined. Metformin caused beneficial changes in blood glucose, HbA1c levels, and HDL in type 2 diabetic rats. Both administration of metformin and exercise intervention independently caused beneficial changes in blood glucose. However, the surprising result found was that exercise intervention did not optimize the result of metformin treatment. The other finding of this study was that exercise intervention increased cholesterol and NOS level but exercise combined with metformin was not better than exercise alone. Thus, it appears from the present study that metformin and exercise combination has no effect.

Comparative Effects of Antidiabetic Drug, Metformin and Deferoxamine, on the Hepatotoxic and Nephrotoxic Side Effects of Streptozotocin-induced Diabetes Mellitus in Rats

“…In the present study, streptozotocin injection caused β cells degeneration in rats, therefore, release of insulin by the pancreas was decreased resulting in hyperglycaemia. This confirms induction of experimental diabetes in rats .This is similar to the findings of several earlier researchers [3,17].…”

“…According to Masiello et al [30], administration of streptozotocin (STZ) and nicotinamide (NA) produced moderate hyperglycaemia which has clinical similarities especially with respect to the insulin response to the glucose [3,36] and as such streptozotocinnicotinamide (STZ-NA) is a method currently used to induce diabetes in animals that resemble non obese type 2 Diabetes mellitus (DM) in man [37]. Hence, STZ-NA induced diabetes model was used in the present study.…”

“…Diabetes mellitus (DM), especially type 2, represents one of the most important health problems worldwide and is likely to worsen to critical levels in the next decades, with the great concern that this disease is rising rapidly in younger population groups, including children and adolescents [1]. The chronic hyperglycaemia of diabetes is associated with long-term damage, dysfunction, and failure of different organs, especially the eyes, kidneys, nerves, heart, and blood vessels [2,3]. Renal impairment is one of the serious and common diabetic complications [4].…”

Blood Glucose Level, Pancreatic Histology and Insulin-Expression in Diabetic Rats Following Metformin and Glibenclamide Administration

“…The blood glucose levels of the STZ -induced diabetictreated groups were statistically reduced compared to the DC group. This result indicates that Metformin and Glibenclamide have anti-diabetic potentials as earlier documented [19]. This is consistent with the report of Okonkwo and Okoye [20], of a reduction in blood glucose levels in diabetic rats treated with Metformin.…”

Blood Glucose Concentration, Pancreatic Histology and Insulin-Expression following Metformin and Glibenclamide Administration in Diabetic Rats

“…This result indicates that metformin and glibenclamide have antidiabetic potentials as earlier documented. 19 This is consistent with the report of Okonkwo and Okoye 20 of a reduction in blood glucose levels in diabetic rats treated with metformin. The blood glucose lowering effect of metformin is dependent on the presence of insulin.…”