[Changes in oxidative systems of liver microsomes in rats following a single administration of phenobarbital and morphine].

During the first three hours after a single administration of phenobarbital or morphine into rats a marked increase was observed in the activity and content of the respiratory chain components responsible for the oxidation of NAD-H2 and NADP-H2 in liver microsomes. This activation of oxidative enzymes correlated with the disappearance of hypnotic and analgetic effects of the narcotics. The phase following the normalization of oxydative systems was characterized by the increase of microsomal enzymes level. This is related to their specific induction only by phenobarbital.