Alterations in Autonomic Nervous System and Heart Mitochondrial Function in Rats Treated with Cyclophosphamide

This study was designed to determine the changes in the autonomic nervous system and heart mitochondrial function in rats treated with cyclophosphamide, an antitumor agent. Rats were divided into two groups: the control group, which remained untreated, and the cyclophosphamide group, which received cyclophosphamide (100mg/kg) intraperitoneally once a day for four consecutive days. In both groups, enzymic activities of the heart mitochondrial electron transport chain were measured. Acetylcholine and norepinephrine contents in the left ventricles were also determined. Significant decreases in mitochondrial electron transport activities were observed in rats treated with cyclophosphamide. Cyclophosphamide treatment also increased acetylcholine and norepinephrine contents. It is well known that the sympathetic nervous system plays an important role in the genesis of cardio-myopathy, and we reported the involvement of the parasympathic nervous system in the pathogenesis of cardiomyopathy. Accordingly, alterations in autonomic nervous function might be linked to the development of mitochondrial dysfunction, although it remains unclear whether the effects of cyclophosphamide on mitochondrial function are direct or indirect.