Greenwald L, Kirschner L B, Sanders M
J Gen Physiol. 1974 Aug;64(2):135-47.
Sodium extrusion (J(out) (Na)) was measured across the gills of rainbow trout, Salmo gairdneri, adapted to sea water (SW) using a gill-irrigation system of small volume. The potential difference (TEP) was also measured under similar conditions. J(out) (Na) was usually between 100-250 microeq (100 g)(-1) h(-1), about an order of magnitude faster than in fresh water (FW)-adapted trout, but slower than has been reported for any other marine teleost. The TEP was between 10-11 mV, body fluids positive to SW. When the external medium was changed from SW to FW J(out) (Na) was reduced to about 25 % of the initial value, and the TEP was reduced by 40-50 mV (i.e. body fluids negative by 30-40 mV). Addition of either Na(+) or K(+) in SW concentrations reversed the changes; J(out) (Na) increased and the gill repolarized. The electrical behavior and sodium efflux in irrigated trout gill is qualitatively the same as has been reported for unanaesthetized, free-swimming fish of other species. Thus, the irrigated gill provides an adequate model for studying the mechanism of sodium extrusion in marine teleosts.
采用小体积鳃灌注系统，对适应海水（SW）的虹鳟鱼（Salmo gairdneri）鳃部的钠排出量（J(out)(Na)）进行了测定。在相似条件下还测量了电位差（TEP）。J(out)(Na)通常在100 - 250微当量（100克）⁻¹ 小时⁻¹之间，比适应淡水（FW）的鳟鱼快约一个数量级，但比其他任何海洋硬骨鱼的报道速度都慢。TEP在10 - 11毫伏之间，体液相对于SW呈正电。当外部介质从SW变为FW时，J(out)(Na)降至初始值的约25%，TEP降低40 - 50毫伏（即体液负电30 - 40毫伏）。添加SW浓度的Na⁺或K⁺可逆转这些变化；J(out)(Na)增加，鳃重新极化。灌注鳟鱼鳃的电行为和钠流出在定性上与其他物种未麻醉、自由游动的鱼的报道相同。因此，灌注鳃为研究海洋硬骨鱼钠排出机制提供了一个合适的模型。
