Mimata T, Inomata H
First Department of Internal Medicine, Tohoku University School of Medicine, Japan.
Eur J Pharmacol. 1989 Apr 12;163(1):181-5. doi: 10.1016/0014-2999(89)90416-0.
The ionic mechanism underlying the time-dependent alteration in the action potential configuration by noradrenaline (NA) was studied using vas deferens muscles voltage-clamped according to the double sucrose gap method. Early exposure to NA enhanced the inward Ca2+ current (ICa) by increasing conductance whereas late exposure diminished ICa by reducing the driving force. The degree of increase in the peak outward K+ current (IK') was higher with a greater enhancement of ICa by NA but the late outward K+ current (IK) was insensitive to NA.
采用双蔗糖间隙法对输精管肌肉进行电压钳制，研究了去甲肾上腺素（NA）引起动作电位构型随时间变化的离子机制。早期暴露于NA通过增加电导增强内向Ca2+电流（ICa），而晚期暴露则通过降低驱动力减少ICa。NA对内向Ca2+电流增强越大，外向K+电流峰值（IK'）增加的程度越高，但晚期外向K+电流（IK）对NA不敏感。
