[Effect of quinine, a blocker of Ca2+-activated K+-channels, on lymphocyte activation by mitogens]

Quinine inhibits mitogenesis at the same concentration (10(-4) M) as that which blocks Ca++-dependent potassium transport in lymphocytes. Lower quinine concentrations (10(-8)-10(-6) M) induce a comitogenic effect which is most pronounced when Ca++-ionophore A23187 is used as a mitogen. Thus, activation of Ca++-dependent K+-channels is not necessary to trigger mitogenesis, but is important for further stages of the process.