Greenwald L E, Kirschner L B
J Membr Biol. 1976 May;26(4):371-83. doi: 10.1007/BF01868884.
The action of poly-L-lysine (PLL) on Na and Cl transport across freshwater fish gills was studied. Low concentration (10-6M) were added to the external medium for brief periods (1--5 min), then removed. During the next 20 min there was a rapid net loss of Na (117+/17 muEquiv[100 g]-1hr-1) and Cl (129+/17 muEquiv[100 g]-1hr-1). Both values are an order of magnitude larger than unidirectional effluxes in control fish. The efflux of both ions decreased to control values within 60 min after application and removal of PLL. In contrast, unidirectional influxes (JCl in and JNa in) were inhibited by about 40+ and showed no sign of returning to the original rates for 3 hr. Thus, PLL has two independent actions, causing a large increase in gill permeability which is reversible within an hour and apartial inhibition of influx which showed no sign of reversing for 2--3 hr. When PLL was applied for a longer period (60 min, the results were qualitatively similar but the permeability change was larger and persisted longer. These effects were compared with those of the small organic amines, amiloride and methyl-L-lysine. The latter inhibited JNa in, but there was not other similarity to PLL. Neither affected sodium efflux, not did they have any effect on Cl movements, in or out, across the gill. Inhibition of JNa in, was rapidly and completely reversible, and amiloride was shown to act by competing with Na for an entry site.
研究了聚-L-赖氨酸（PLL）对淡水鱼鳃中钠和氯转运的作用。将低浓度（10-6M）的PLL添加到外部介质中短时间（1-5分钟），然后去除。在接下来的20分钟内，钠（117±17微当量/[100克]-1小时-1）和氯（129±17微当量/[100克]-1小时-1）出现快速净损失。这两个值比对照鱼的单向流出量高一个数量级。在应用和去除PLL后60分钟内，两种离子的流出量均降至对照值。相比之下，单向流入量（JCl in和JNa in）被抑制了约40%，并且在3小时内没有恢复到原始速率的迹象。因此，PLL有两种独立的作用，导致鳃通透性大幅增加，这种增加在一小时内是可逆的，并且对流入有部分抑制作用，在2-3小时内没有逆转的迹象。当PLL应用更长时间（60分钟）时，结果在定性上相似，但通透性变化更大且持续时间更长。将这些效应与小有机胺、氨氯吡脒和甲基-L-赖氨酸的效应进行了比较。后者抑制JNa in，但与PLL没有其他相似之处。它们都不影响钠的流出，也对氯穿过鳃的进出运动没有任何影响。对JNa in的抑制迅速且完全可逆，并且氨氯吡脒被证明是通过与钠竞争进入位点而起作用的。
