17β-雌二醇对大鼠海马神经元延迟整流型钾离子通道活动的影响

用膜片箝技术的细胞贴附式和内面向外式,研究17β-雌二醇（E2）对大鼠海马神经元延迟整流型K 通道的影响。结果表明,1．0和10．0nmol／LE2可分别使42pSK 通道开放概率由（67．4t18．2）％下降到（41．22±12．5）％和由（56．3±15．8）％下降到（13,2±12．6）％,通道开放频率由（43．40±6．7）Hz下降到（27．68±9．1）Hz和由（38．19±10．1）Hz下降到（15．79±3．5）Hz,通道平均开放时间缩短,平均关闭时间延长,但通道电流幅度无显著改变,提示E2对海马神经元42pSK 通道的活动具有抑制作用,这种作用可能是激素直接作用于细胞膜的结果。

Effects of 17 beta-estradiol on delayed rectifier potassium channels in hippocampal pyramidal neurons of the rat

In the present study, both cell-attached and inside-out patch-clamp techniques were used to detect the effects of 17 beta-estradiol (E2) on 42 pS delayed rectifier potassium channels in acutely dissociated hippocampal neurons of new-born SD rats. The results indicated that after application of 1.0 and 10.0 nmol/L E2, the open probabilities of K+ channels were decreased from (67.4 +/- 18.2)% to (41.2 +/- 12.5)% and from (56.3 +/- 15.8)% to (13.2 +/- 12.6)% respectively, the open frequencies were reduced from (43.40 +/- 6.7) Hz to (27.68 +/- 9.1) Hz and from (38.19 +/- 10.1) Hz to (15.79 +/- 3.5) Hz respectively. Meanwhile, there was a shortening of the mean open time and a lenghtening of the mean close time of the channels. The above results suggest that E2 has suppressive effects on the activities of the channels, which might be exerted through a direct action on the cellular membrane.