Effects of Catalase on Volume-Overload Heart Failure

Exogenous oxygen free radicals (OFRs) have been reported to depress cardiac function and contractility. The decrease in cardiac function and contractility in chronic volume overload could be due to increased levels of OFRs. We therefore investigated the effects of volume overload of 9 months duration in the absence and presence of catalase treatment on cardiac function and contractility; left ventricular malondialdehyde (MDA), a lipid peroxidation product; and left ventricular antioxidant reserve, measured as left ventricular chemiluminescence (LV-CL) in dogs. Dogs were divided into three groups: group I, control; group II, mitral regurgitation (MR) of 9 months duration; and group III, same as group II but supplemented with polyethylene glycol (PEG)-catalase (5000IU/kg/week, intravenously).