In vitro stimulation of Na+-K+-ATPase activity and ouabain binding by cortisol in coho salmon gill.
In vitro stimulation of Na+-K+-ATPase activity and ouabain binding by cortisol in coho salmon gill.
复制标题
银鲑鱼鳃中皮质醇对 Na-K-ATP 酶活性和哇巴因结合的体外刺激。
DOI:
10.1152/ajpregu.1989.256.3.r707
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发表时间:
1989
期刊:
影响因子:
--
通讯作者:
H. Bern
中科院分区:
文献类型:
--
作者:
S. McCormick;H. Bern
To investigate the hormonal control of gill Na+-K+-adenosinetriphosphatase (ATPase) (the sodium pump) in coho salmon, a technique for the culture of primary gill filaments for up to 4 days was developed. Trypan blue exclusion was greater than 99.9%, histological appearance of the cells was normal, and total [Na+], [K+], and protein content of gill filaments cultured for 2-4 days was unchanged from initial levels (measured immediately after isolation). In fish with initially low gill Na+-K+-ATPase activity (presmolts), cortisol (0.1, 1.0, and 10.0 micrograms/ml) caused a significant dose-dependent increase in gill Na+-K+-ATPase activity over initial (41%) and control levels (45%) after 4 days in culture. In fish with initially high gill Na+-K+-ATPase activity (postsmolts), cortisol partially prevented the decline in activity that occurred during 4 days of culture. The relative ability of steroids to increase gill Na+-K+-ATPase activity was dexamethasone greater than cortisol = 11-deoxycortisol greater than cortisone. Insulin (0.1, 1.0, and 10.0 micrograms/ml), alone or in combination with cortisol, had no significant effect on gill Na+-K+-ATPase activity. Cortisol treatment significantly increased maximum binding capacity of [3H]ouabain in gill tissue (from 2.92 to 5.22 pmol/mg dry wt) but had no significant effect on the dissociation constant. These results demonstrate that cortisol has direct effects on the osmoregulatory physiology of the teleost gill.