Abstract
NADH-cytochrome c reductase and NADH dehydrogenase activities in liver cell membranes were not effected by orchiectomy and ovariectory. Time required for the elevation of these enzyme activities following CCl4 administration in orchiectomized rats was, however, apparently shortened and comparable with that in the non-treated females. Administration of 17-α-methyltestosterone recovered completely the response to CCl4 as was seen in the male controls. In female rats, ovariectomy or administration of diethylstilbestrol produced no effects on the CCl4induced changes of membrane enzyme activities. Membrane ATPase activity decreased following CCl4 administration in such hormonal states of rats that the reductase and the dehydrogenase activities were increased. Male sex hormone appears to suppress changes of these enzyme activities in the membranes following CCl4 administration.
