目的:研究17β-雌二醇(E2)对小鼠生精细胞T型钙电流(ICaT)的影响。方法:采用膜片钳全细胞记录技术观察E2对急性机械分离的小鼠生精细胞ICaT的影响。结果:E2(1、10、100μmol/L)呈浓度、电压依赖性抑制小鼠生精细胞钙电流,抑制率分别为(13.48±1.86)%、(28.98±2.70)%和(52.93±3.42)%(n=6,P〈0.05)。E2对T型钙通道的半数最大抑制浓度(K。)为8.89μmol/L。100μmol/L E2显著改变T型钙通道的激活和失活特性:半数激活电压(Va1/2)和激活斜率因子(Ka)分别从(-48.94±0.22)mV、(5.19±0.19)mV变为(-54.34±1.02)mV和(6.02±0.84)mV(n=5,P〈0.05);而半数失活电压(Vi1/2)和失活斜率因子(Ki)分别从(-56.51±0.13)mV、(3.36±0.11)mV变为(-61.78±0.50)mV、(4.25±0.37)mV(n=5,P〈0.05)。结论:E2对生精细胞T型钙通道有抑制作用,呈浓度依赖性。
Objective: To investigate the effect of 17±estradiol (E2) on T-type calcium currents ( ICaT ) in spermatogenic cells. Methods: Ca^2+ currents were obtained in acutely dissociated mouse spermatogenic cells by the whole-cell patch clamp technique and the effects of E2 on ICaT were observed. Results : E2 at the concentrations of 1, 10 and 100μmol/L significantly inhibited ICaT in the mouse spermatogenic cells, with the KC50 value of 8.89 μmol/L and the inhibition rates of ( 13.48 ± 1.86) %, (28.98±2.70) and (52.93 ± 3.42) %, respectively ( n = 6, P 〈 0.05 ). E2 of 100 μmol/L significantly changed the activation and inactivation of ICaT- the half activation potential (Va1/2) and the activation steepness factor (Ka) from ( -48.94± 0.22) mV and (5.19 ±0.19) mV to ( - 54.34 ± 1.02 ) mV and ( 6.02± 0.84) mV ( n = 5, P 〈 0.05 ), and the half inactivation potential ( Va1/2) and the inactivation steepness factor (Ki) from ( -56.51 ±0. 13) mV and (3.36±0.11) mV to ( -61.78 ±0.50) mV and (4.25 ±0.37) mV, respectively ( n = 5, P 〈 0.05 ). Conclusion : E2 has a significant inhibitory effect on ICaT in mouse spermatogenic cells in a concentration-dependent manner.