The functional activity of adult mouse Leydig cells in monolayer culture. Effect of lutropin and foetal calf serum.

Purified Leydig cells were obtained from adult mouse testes by mechanical dispersion followed by Percoll density-gradient centrifugation as described by Schumacher et al. (1978). The cells were then established in monolayer culture by maintaining them in medium and 10% serum at 32 degrees C in 95% O2, 5% CO2. The cells rapidly attached to the culture dishes, gradually flattened and became epitheloid in appearance. Testosterone production by the cells in response to maximum stimulating levels of LH (100 ng/ml) and dibutyryl cyclic AMP (1 mM) was maintained for at least 2 days (approximately 1 microgram/10(6) cells/2h) and then declined to lower levels by days 3-4. Cyclic AMP production in response to LH was higher on day 1 than day 0 and then declined to lower levels by days 3-4. Binding of [125I]hCG was similar on day 0 and day 1 (approximately 20 fmoles/10(6) cells) and then declined to lower levels by days 3-4. The functional activity of the cells cultured in 0, 1 and 10% foetal calf serum was also examined; no significant effect of the serum on LH-stimulated testosterone or cyclic AMP production was found; however, a decrease of up to 50% in the binding of [125I]hCG to the Leydig cells occurred in the presence of serum. These results demonstrate that the function of differentiated adult Leydig cells can be maintained for at least 2 days in culture.