ROTENONE-SENSITIVE OXIDATION OF NADH AND ACTIVITY OF F0F1-ATPASE IN RAT SKELETAL-MUSCLE HOMOGENATES DURING THERMAL ADAPTATION

A method has been developed for measuring rates of rotenone-sensitive NADH oxidation and oligomycin-sensitive ATP hydrolysis in rat skeletal muscle homogenates. The method is based on the ability of alamethicin to increase the permeability of the inner mitochondrial membrane for NADH and ATP. It is shown that prolonged cold adaptation of rats (four weeks at 4-degrees-C) does not affect rotenone-sensitive NADH oxidase activity (12.4 +/- 4.4. nmoles NADH/min per mg protein), but increase s three-fold F0F1-ATPase activity (from 31.8 +/- 7.4 to 93.1 +/- 14.3 nmoles P(i)/min per mg protein) in rat skeletal muscle homogenates. It is suggested that prolonged cold adaptation induces structural and fu nctional changes in the H+-ATP-synthase complex of skeletal muscle mit ochondria.