The Ca2+-activated, large conductance K+-channel (BKCa) is a player in the LH/hCG signaling cascade in testicular Leydig cells

► The Ca2+-activated K+-channel (BKCa) is expressed by Leydig cells in adult hamster and human testis. ► BKCa is activated upon LH-receptor activation. ► It is responsible for the hCG-induced hyperpolarization of the Leydig cell membrane. ► Inhibition of BKCa abolishes hyperpolarization but increases testosterone and StAR levels. ► Thus BKCa is involved in limiting the production of testosterone evoked by LH-receptor activation.