Effects of selenium on altered mechanical and electrical cardiac activities of diabetic rat

• Published in: Archives of biochemistry and biophysics Vol. 426; no. 1; pp. 83 - 90
• Main Authors: Ayaz, Murat, Ozdemir, Semir, Ugur, Mehmet, Vassort, Guy, Turan, Belma
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.06.2004
• Subjects: Action potential; Action Potentials - drug effects; Action Potentials - physiology; Animals; Blood Glucose - drug effects; Blood Glucose - metabolism; Body Weight; Contraction; Diabetes Mellitus, Experimental - drug therapy; Diabetes Mellitus, Experimental - metabolism; Diabetes Mellitus, Experimental - physiopathology; Electric Capacitance; Electric Stimulation; Electrophysiology; Female; Glutathione metabolism; Heart - drug effects; Heart - physiopathology; Insulin - blood; K + currents; Male; Myocardial Contraction - drug effects; Myocardial Contraction - physiology; Myocardium - metabolism; Myocytes, Cardiac - drug effects; Myocytes, Cardiac - physiology; Papillary Muscles - drug effects; Papillary Muscles - physiology; Potassium Channels - drug effects; Potassium Channels - physiology; Rats; Rats, Wistar; Sodium selenite; Sodium Selenite - pharmacology; Action potential; Sodium selenite; Glutathione metabolism; K + currents; Contraction
• ISSN: 0003-9861; 1096-0384
• DOI: 10.1016/j.abb.2004.03.030

Since selenium compounds can restore some metabolic parameters and structural alterations of diabetic rat heart, we were tempted to investigate whether these beneficial effects extend to the diabetic rat cardiac dysfunctions. Diabetes was induced by streptozotocin (50 mg/kg body weight) and rats were then treated with sodium selenite (5 μmol/kg body weight/day) for four weeks. Electrically stimulated isometric contraction and intracellular action potential in isolated papillary muscle strips and transient ( I to) and steady state ( I ss) outward K + currents in isolated cardiomyocytes were recorded. Sodium selenite treatment could reverse the prolongation in both action potential duration and twitch duration of the diabetic rats, and also cause significant increases in the diminished amplitudes of the two K + currents. Treatment of rats with sodium selenite also markedly increased the depressed acid-soluble sulfhydryl levels of the hearts. Our data suggest that the beneficial effects of sodium selenite treatment on the mechanical and electrical activities of the diabetic rat heart appear to be due to the restoration of the diminished K + currents, partially, related to the restoration of the cell glutathione redox cycle.