A quantitative analysis of the acetylcholine-activated potassium current in single cells from frog atrium.
A quantitative analysis of the acetylcholine-activated potassium current in single cells from frog atrium.
复制标题
青蛙心房单细胞乙酰胆碱激活钾电流的定量分析。
DOI：
10.1007/bf00583801
复制
发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Hartzell,HC
中科院分区：
文献类型：
--
作者：
Simmons,MA;Hartzell,HC
The K+current activated by acetylcholine (ACh) in single cells from the frog atrium was analyzed using the whole-cell patch clamp technique. The ACh current was analyzed quantitatively by subtracting the currents elicited in response to voltage steps in the presence and absence of a steady bath-application of 1 μM ACh. The net ACh currents were voltage- and time-dependent. With depolarizing jumps, the ACh-activated current declined from an instantaneous peak to a new steady level. With hyperpolarizations, the instantaneous current change was followed by a time-dependent increase in current. The current relaxations were well fitted by the sum of two exponentials with time constants of ∼20 ms and ∼300 ms at −120 mV. Both time constants decreased with depolarization. The current-voltage relationship inwardly-rectified. This inward rectification was due both to a decrease in the single channel conductance and a decrease in the number of open channels with depolarization. The ACh-activated K+current differs from the background K+current in several respects. The kinetics of the background K+current are much more rapid and the background K+channel passes much less current in the outward direction than the ACh channel.
