Mitochondrial oxidative damage and myocardial fibrosis in rats chronically intoxicated with moderate doses of ethanol.

Mitochondrial oxidative balance and myocardial fibrosis were investigated in pair-fed rats received ethanol (3%) or saccharose in drinking water for 8 weeks. The concentrations of glutathione, malondialdehyde, protein carbonyls and sulfhydrils were determined. The presence and distribution of fibronectin were detected by immunohistochemistry. The myocardial concentrations of reduced glutathione and protein sulfhydrils were lower in ethanol treated rats. The oxidised/reduced glutathione ratio, the levels of malondialdehyde and protein carbonyls were higher in ethanol-treated rats. The mitochondrial amount of proteins, glutathione and protein sulfhydrils were lower in ethanol treated rats, whereas the content of protein carbonyls and malondialdehyde were higher. Accumulation of fibronectin was detected at subepicardial and subendocardial districts in ethanol-treated rats, with moderate degree of fibrosis in 20% of the cases. In conclusion, moderate ethanol consumption is associated with oxidative damage to heart mitochondria and fibronectin deposition. These oxidative and ultrastuctural changes may be assumed as basic alterations in the development of alcoholic cardiomyopathy.