ATP-Sensitive K+ Channels in Pancreatic β-Cells: Spare-Channel Hypothesis
ATP-Sensitive K+ Channels in Pancreatic β-Cells: Spare-Channel Hypothesis
复制标题
胰腺 β 细胞中 ATP 敏感的 K+ 通道：备用通道假说
作者：
D. Cook;L. Satin;Michael L.J. Ashford;C. Hales
Since their discovery in pancreatic β-cells, ATP-sensitive K+ channels in the cell membrane have been thought to mediate glucose-induced β-cell depolarization, which is required for triggering the voltage-dependent Ca2+ uptake subserving insulin release. The theory is that metabolism of glucose (and other fuel molecules) increases intracellular ATP or possibly other metabolites that diffuse to the membrane and inhibit the opening of ATP-sensitive K+ channels. This slows the efflux of positively charged K+ and depolarizes the cell. A recurrent source of confusion regarding this idea stems from the early observation that these channels are so exquisitely sensitive to intracellular ATP that channel opening is predicted to be ∼99% inhibited under physiological conditions. To account for this apparent discrepancy, various mechanisms have been proposed that might render the channels less sensitive to intracellular ATP. We use a simple mathematical model to demonstrate that there is no major discrepancy and that, in fact, given the electrophysiological mechanisms existing in the β-cell, the extreme sensitivity of the channels to ATP is appropriate and even mandatory for their physiological function.
DOI：
10.1016/s0021-9258(18)66958-3
发表时间：
1986-10
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
D. Miller;S. B. Horowitz
通讯作者：
D. Miller;S. B. Horowitz
影响因子：
56.9
作者：
J. Weiss;S. Lamp
通讯作者：
J. Weiss;S. Lamp
DOI：
10.1073/pnas.83.18.7119
发表时间：
1986-09-01
影响因子：
11.1
作者：
MISLER, S;FALKE, LC;MCDANIEL, ML
通讯作者：
MCDANIEL, ML