Respiration and oxidative phosphorylation by muscle and heart mitochondria of hamsters with hereditary myocardiopathy and polymyopathy

Abstract

Mitochondria isolated from skeletal muscle and heart of normal Syrian hamsters and from hamsters of the BIO 14.6 myopathic strain aged 97-124 days were studied. Histological examination of the tissues and serum creatine phosphokinase determinations established that the disease was active in the dystrophic animals. In the mitochondrial isolation procedure the minced tissue was incubated before homogenization in a mannitol-sucrose-EDTA medium containing a proteinase (Nagarse). Polarographic estimations with pyruvate-malate as substrate, in the presence and absence of ADP, indicated that the rate of O2 uptake, ADP/O ratio, and respiratory control ratio (state 3 to 4 transition) of the heart mitochondria did not differ significantly between the normal and myopathic groups. The findings with the skeletal muscle mitochondria were similar. L-[alpha]-Glycerophosphate oxidation also was not affected by the myopathy but the rate of NADH oxidation was 35% slower in the heart mitochondria of the BIO 14.6 strain.