Oral administration of sodium tungstate improves cardiac performance in streptozotocin-induced diabetic rats

• Published in: Canadian journal of physiology and pharmacology Vol. 83; no. 5; pp. 405 - 411
• Main Authors: Nagareddy, Prabhakara Reddy, Vasudevan, Harish, McNeill, John H
• Format: Journal Article
• Language: English
• Published: Ottawa, Canada NRC Research Press 01.05.2005; National Research Council of Canada; Canadian Science Publishing NRC Research Press
• Subjects: Administration, Oral; Animals; Biological and medical sciences; Body Weight - drug effects; Cardiomyopathies - etiology; Cardiomyopathies - prevention & control; Diabetes Mellitus, Experimental - blood; Diabetes Mellitus, Experimental - drug therapy; Diabetes Mellitus, Experimental - metabolism; Drinking - drug effects; Eating - drug effects; Fatty Acids, Nonesterified - blood; General and cellular metabolism. Vitamins; Glucose Tolerance Test; Heart Function Tests; Hypoglycemic Agents - administration & dosage; Hypoglycemic Agents - therapeutic use; Insulin - blood; Insulin - metabolism; Male; Medical sciences; Myocardial Contraction - drug effects; Pharmacology. Drug treatments; Rats; Rats, Wistar; Streptozocin; Triglycerides - blood; Tungsten Compounds - administration & dosage; Tungsten Compounds - adverse effects; Tungsten Compounds - therapeutic use; Ventricular Function, Left - drug effects; Endocrinopathy; Heart; Animal model; Cardiac performance; Rat; Cardiomyopathy; Cardiovascular disease; Lipids; Tungstates; Myocardial disease; Hyperglycemia; Heart disease; Hyperlipemia; Dyslipemia; Diabetes mellitus; Rodentia; Oral administration; Metabolic diseases; Glucose tolerance test; Vertebrata; Mammalia; Treatment; Dysfunction; Animal; Circulatory system
• ISSN: 0008-4212; 1205-7541
• DOI: 10.1139/y05-026

Normalization of hyperglycemia and hyperlipidemia is an important objective in preventing diabetes-induced cardiac dysfunction. Our study investigated the effects of sodium tungstate on cardiac performance in streptozotocin-induced (STZ) diabetic rats based on its potential antidiabetic and antioxidant activity. Male Wistar rats were made STZ-diabetic and then treated with tungstate in their drinking water for 9 weeks. Body mass, food and fluid intake, plasma glucose, insulin, triglyceride, and free fatty acids levels were measured. At the termination of the study period, an oral glucose tolerance test (OGTT) was performed, and cardiac performance was evaluated using an isolated working heart apparatus. Tungstate-treated STZ-diabetic rats showed a significant reduction in fluid and food intake, plasma glucose, triglycerides, and free fatty acid levels, and improved tolerance to glucose in OGTT, owing to tungstate-mediated enhancement of insulin activity rather than increased insulin levels. Left ventricular pressure development, the rate of contraction (+dP/dT), and the rate of relaxation (-dP/dT) were significantly improved in tungstate-treated diabetic rats. Apart from a decreased rate of body mass gain, no other signs of toxicity or hypoglycemic episodes were observed in tungstate-treated rats. This study extends previous observations on the antidiabetic activities of tungstate, and also reports for the first time the salutary effects in preventing diabetic cardiomyopathy.Key words: diabetes, cardiomyopathy, tungstate, isolated working heart, oral glucose tolerance test.