Mitochondrial P-450 activities in aldosteronoma tissues

Adrenal P-450 activities were measured by an in vitro reconstitution system from tissues obtained from human aldosteronomata, and the results compared with those of the normal adrenal tissues from patients with Grawitz's tumor. The P-45011β activity was significantly increased in adenoma tissue (55.6 ± 5.3 vs 9.0 ± 6.2 nmol corticosterone/mg of protein/min in the control tissues, P < 0.01). P-450scc activity in adrenal adenomata was 13.4 ± 2.0 nmol pregnenolone/mg of protein/min, significantly higher than control (P < 0.05). The present results suggest that increased mitochondrial P-45011β activities may be characteristic of aldosterone-producing adenomata.