Stress-induced alterations in microsomal drug metabolism in the rat

Stress alone and in combination with phenobarbital has been investigated for its stimulatory effects on hepatic microsomal drug metabolism in the rat. Stress (cold) caused increases in the rate of p-hydroxylation of aniline. N-dealkylation of ethylmorphine, and increases in adrenal ascorbic acid content. The stimulatory actions of stress on microsomal metabolism and ascorbic acid levels are additive with those produced by phenobarbital. It is tentatively concluded that stress and phenobarbital appear to act through different mechanisms in inducing increases in enzyme activity, although each treatment may have a common final step, namely an increased net synthesis of enzyme protein.