Simultaneous release of androgens and progesterone by gerbil (Meriones unguiculatus) dispersed testicular interstitial cells under basal conditions and after stimulation with luteinizing hormone.

The production of androgens and progesterone by dispersed gerbil interstitial cells was studied in vitro. Incubation of 80,000-100,000 cells with 2.3-143.8 microIU LH/vial resulted in a 1.9-8.0 fold increase of androgen and in a 2.2-19.8 fold increase of progesterone release. The ratio of androgens/progesterone released by gerbil interstitial cells was 8.1 in the absence of LH, and was significantly higher in the presence of 143.8 microIU LH/vial (17.7). In all cell assays performed (n = 5), a highly significant positive correlation between LH-stimulated androgen and progesterone release was found. In comparison with androgen biosynthesis in vitro in either the rat or mouse, gerbil, interstitial cells are much more sensitive to LH as argued from both androgen and progesterone release. The reason for this high responsiveness of gerbil interstitial cells is not clear; it may be due in part to the very low bioactive LH levels in gerbils leaving a major part of LH receptors unoccupied thus allowing even trace amounts of LH to fully activate steroidogenesis.