Morris Catherine E, Juranka Peter F, Lin Wei, Morris Terence J, Laitko Ulrike
Department of Medicine, University of Ottawa, Ontario, Canada.
Methods Mol Biol. 2006;322:315-29. doi: 10.1007/978-1-59745-000-3_22.
The mechanosensitivity of voltage-gated (VG) channels is of biophysical, physiological. and pathophysiological interest. Xenopus oocytes offer a critical advantage for investigating the electrophysiology of recombinant VG channels subjected to membrane stretch, namely, the ability to monitor macroscopic current from membrane patches. High-density channel expression in oocytes makes for macroscopic current in conventional-size, mechanically sturdy patches. With the patch configuration, precisely the same membrane that is voltage-clamped is the membrane subjected to on-off stretch stimuli. With patches, meaningful stretch dose responses are possible. Experimental design should facilitate within-patch comparisons wherever possible. The mechanoresponses of some VG channels depend critically on patch history. Methods for minimizing and coping with interference from endogenous voltage-dependent and stretch-activated endogenous channels are described.
电压门控（VG）通道的机械敏感性具有生物物理、生理和病理生理学意义。非洲爪蟾卵母细胞为研究受膜拉伸的重组VG通道的电生理学提供了关键优势，即能够监测来自膜片的宏观电流。卵母细胞中的高密度通道表达使得在常规大小、机械坚固的膜片中产生宏观电流成为可能。采用膜片钳配置时，被电压钳制的膜与受到开-关拉伸刺激的膜完全相同。有了膜片，就可以得到有意义的拉伸剂量反应。实验设计应尽可能便于膜片内的比较。一些VG通道的机械反应严重依赖于膜片的历史状态。本文描述了最小化和应对内源性电压依赖性及拉伸激活内源性通道干扰的方法。
