Marshall W S, Klyce S D
Biochim Biophys Acta. 1984 Nov 21;778(1):139-43. doi: 10.1016/0005-2736(84)90457-7.
The present work examines serotonin-induced changes in cell potential difference and barrier resistances in the corneal epithelium in vitro using voltage-measuring microelectrodes and related techniques. Component resistances were determined using voltage and resistance profiles of the epithelium before and during the serotonin response. Serotonin, added to the stromal side of the cornea in the presence of nialamide, markedly reduced transcorneal and apical membrane resistances, while basal barrier resistance increased slightly and shunt resistance was unchanged. The marked drop in apical membrane resistance after serotonin treatment reflects an increase in apical membrane chloride permeability, inasmuch as the serotonin-stimulated short-circuit current is indistinguishable from the increase in net chloride flux. Prolonged (more than 1 h) exposure of corneas to serotonin markedly depolarized the epithelial cells and reduced the voltage divider ratio from 12.3 +/- 2.1 to 1.5 +/- 0.5, while not significantly affecting the stimulated short-circuit current. These later effects suggest changes in epithelial ion distribution during long periods of stimulation by serotonin.
本研究使用电压测量微电极及相关技术，在体外检测血清素诱导的角膜上皮细胞电位差和屏障电阻的变化。通过血清素反应前后上皮细胞的电压和电阻曲线来确定各组成电阻。在烟肼酰胺存在的情况下，将血清素添加到角膜基质侧，可显著降低经角膜电阻和顶端膜电阻，而基底屏障电阻略有增加，旁路电阻则保持不变。血清素处理后顶端膜电阻的显著下降反映了顶端膜氯化物通透性的增加，因为血清素刺激引起的短路电流与净氯化物通量的增加无法区分。角膜长时间（超过1小时）暴露于血清素会使上皮细胞明显去极化，并使分压器比率从12.3±2.1降至1.5±0.5，而对刺激引起的短路电流没有显著影响。这些后期效应表明，在血清素长时间刺激期间，上皮细胞离子分布发生了变化。
