[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.
Zhang
J
J
Department of Physiology, Sun Yat-Sen University of Medical Sciences, Guangzhou 510089.
Chen
Z H
ZH
Chen
P X
PX
D000818:Animals; D001693:Biological Transport, Active; D051668:Delayed Rectifier Potassium Channels; D004594:Electrophysiology; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D006624:Hippocampus / Q000502:physiology*; D066298:In Vitro Techniques; D008297:Male; D009474:Neurons / Q000502:physiology; D018408:Patch-Clamp Techniques; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000187:drug effects*; D024642:Potassium Channels, Voltage-Gated; D051381:Rats; D017207:Rats, Sprague-Dawley
D051668:Delayed Rectifier Potassium Channels; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D004958:Estradiol; D011188:Potassium