Pregnenolone-16alpha-carbonitrile-inducible cytochrome P450 in rat liver.

The progesterone derivative, pregnenolone-16alpha-carbonitrile, induces the synthesis of a unique cytochrome P450 peptide in hepatic microsomes of male rats. This form, detectable both spectrally and electrophoretically, is distinct from the cytochrome P450 components synthesized in response to barbiturates or polycyclic hydrocarbons, but may be identical to the major peptide in control microsomes.