Effects of potassium ion efflux on mouse sperm in vitro capacitaion in mice

  Objective   To observe the correlation between the mouse sperm capacitaion state and K⁺ channel and its mechanism.

  Methods   Mice sperm in vitro capacitation was assessed by the B pattern of staining by chlortetracycline (CTC).Then the delayed rectifier K⁺ currents(Ⅰ_DRK)in mouse pachy tene spermatocyte were recorded using whole-cell patch clamp technique.

  Results   When spermatozo a were cultured in valinomycin(Val, a potassium ionophore)at the concentration of 50 nmol/L, the capacitation was increased significantly(n=10, P < 0.05).50 nmol/L Val increased the amplitude of IDRK currents significantly, up-regulated the-Ⅳ curve of IDRK current.

  Conclusion   Valinomcin promotes potassiumion efflux by activation of delayed rectifier potassium channels in mouse pachytene spermatocyte, and then mediated hyperpolarization itself appears capable of inducing sperm capacitation.