Cadmium exposure induces cardiac glucometabolic dysregulation and lipid accumulation independent of pyruvate dehydrogenase activity

Abstract

Context Suppressed glucose metabolism, elevated fatty acid metabolism and lipid deposition within myocardial cells are the key pathological features of diabetic cardiomyopathy. Studies have associated cadmium exposure with metabolic disturbances. Objective To examine the effects of cadmium exposure on cardiac glucose homeostasis and lipid accumulation in male Wistar rats. Methods Male Wistar rats were treated for 21 days as (n = 5): Control, cadmium chloride Cd5 (5 mg/kg, p.o.), cadmium chloride Cd30 (30 mg/kg, p.o). Results The fasting serum insulin level in this study decreased significantly. Pyruvate and hexokinase activity reduced significantly in the Cd5 group while no significant change in lactate and glycogen levels. The activity of pyruvate dehydrogenase enzyme significantly increased with an increasing dosage of cadmium. The free fatty acid, total cholesterol and triglyceride levels in the heart increased significantly with increasing dosage of cadmium when compared with the control. Lipoprotein lipase activity in the heart showed no difference in the Cd5 group but a reduction in the activity in the Cd30 group was observed. Conclusion This study indicates that cadmium exposure interferes with cardiac substrate handling resulting in impaired glucometabolic regulation and lipid accumulation which could reduce cardiac efficiency.