Figure 2.

Inhibitory effects of mibefradil on hCG-stimulated testosterone production in mouse Leydig cells. Purified mouse Leydig cells were incubated in DMEM/F12 medium in the presence (A, C) or absence of 1.0 mmol L⁻¹ Ca²⁺ (B). (A): The onset of steroidogenesis was induced by adding hCG at a concentration ranging from 1 to 100 IU for 30 min or for 1 h. (B): the control experiment is done with Ca²⁺ in the presence of 100 IU hCG whereas the other two are done without Ca²⁺. (C): The cells were all treated with 100 IU hCG to induce testosterone production in the presence of mibefradil, ranging from at 0.01 to 1.00 mmol L⁻¹. All data are means ± SD (n = 5) compared with controls respectively ([0 hCG, A]; [100 IU hCG with Ca²⁺, B]; [0 mibefradil, C]). ^*P < 0.05, compared with corresponding control.