In vitro pregnenolone metabolism by mouse adrenal gland: I-estrogen synthesis.

Adrenal gland homogenates from four different strains of mice were incubated with (4-14C)-pregnenolone and a NADPH generating system. Although quantitative differences between high and low mammary tumor strains occured, all mice synthesized estrone. The highest aromatase activity was found 2 months after castration of the (C3H x RIII) F1 mice when castration was performed at 4 days of age; this activity was lower in the C3H mice and almost negligible in the RIII and C57BL mice.