Margineanu D G, Van Driessche W
Laboratorium voor Fysiologie, K. U. Leuven, Belgium.
Arch Int Physiol Biochim Biophys. 1991 Feb;99(1):83-8. doi: 10.3109/13813459109145908.
The effects of the protein cross-linker glutaraldehyde (GA) on the transepithelial short-circuit current (Isc), conductance (Gt) and impedance of the isolated frog skin were investigated at GA concentrations between 0.1 and 10 mM, i.e. up to three orders of magnitude less than used in fixative procedures. Below 0.5 mM GA increases Isc, with large variations among preparata. Millimolar GA concentrations induce fairly reproducible irreversible inhibitions of Isc, which proceed for about 3 h. The rate of Isc decrease and the amplitudes of the initial drop and subsequent recovery depend on GA concentration in a sigmoidal dose-effect way, reaching saturation at 10 mM. At this GA concentration, Gt is increased up to 5 times the control value. Transepithelial impedance measurements confirm the decreases in epithelial resistance (Rm) and show significant increases in epithelial capacitance (Cm). Rm is diminished by 20% at 0.5 mM GA and by 75% at 10 mM GA, while Cm is maximally augmented by 55% at 2.5 mM GA. It is concluded that protein cross-linking by mild GA treatment is a convenient procedure for changing the electrical characteristics of epithelia.
研究了蛋白质交联剂戊二醛（GA）对离体蛙皮跨上皮短路电流（Isc）、电导（Gt）和阻抗的影响，GA浓度范围为0.1至10 mM，即比固定程序中使用的浓度低三个数量级。低于0.5 mM时，GA会增加Isc，但不同制备样品之间存在很大差异。毫摩尔浓度的GA会引起Isc相当可重复的不可逆抑制，这种抑制持续约3小时。Isc下降速率以及初始下降和随后恢复的幅度以S形剂量效应方式取决于GA浓度，在10 mM时达到饱和。在此GA浓度下，Gt增加至对照值的5倍。跨上皮阻抗测量证实了上皮电阻（Rm）的降低，并显示上皮电容（Cm）显著增加。在0.5 mM GA时，Rm降低20%，在10 mM GA时降低75%，而在2.5 mM GA时，Cm最大增加55%。得出的结论是，通过温和的GA处理进行蛋白质交联是改变上皮细胞电学特性的便捷方法。
