Abstract
The zonal distribution of aldosterone synthase cytochrome P450 (P450ALDO) in the adrenal cortex of male hamsters was investigated by immunofluorescence and electron microscopy, using an anti-P450ALDO peptide antibody. On cryostat sections the immunolocalization of P450ALDO was confined to the zona glomerulosa cells. On semi-thin plastic sections, P450ALDO was shown to be located in mitochondria. Studies in electron microscopy, using the colloidal gold technique, confirmed that P450ALDO was located in mitochondria.