Cytochrome P450 CYP3A5 in the human anterior pituitary gland.

The cytochromes P450 are a key group of enzymes involved in the metabolism of xenobiotics and several biologically active endogenous compounds. The expression of CYP3A5 has been identified by reverse transcriptase-polymerase chain reaction in human pituitary gland and shown by immunohistochemistry to be localized to growth hormone containing cells of the anterior pituitary gland. This is the first direct identification of an individual P450 subfamily in the pituitary gland and the presence of CYP3A in the pituitary gland may play a role in regulating growth hormone secretion.