On the instability of K+ influx in erythrocytes of the rainbow trout, Salmo gairdneri, and the role of catecholamine hormones in maintaining in vivo influx activity
The rate of K+ influx in washed trout erythrocytes was not stable and declined by 60% over a 6 h period, but decreased only slowly thereafter. During this initial period the cells shrank, although [K+]i was maintained constant. Both ouabain-sensitive and furosemide-sensitive K+ influx were reduced b...
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Published in | Journal of experimental biology Vol. 101; no. 1; pp. 93 - 104 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
England
01.12.1982
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Subjects | |
Online Access | Get full text |
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Summary: | The rate of K+ influx in washed trout erythrocytes was not stable and declined by 60% over a 6 h period, but decreased only slowly thereafter. During this initial period the cells shrank, although [K+]i was maintained constant. Both ouabain-sensitive and furosemide-sensitive K+ influx were reduced by approximately equal amounts. Extensive modification of the saline composition produced no diminution of the loss of K+ influx activity, making it unlikely that the response was due to deficiencies in saline composition. The rate of K+ influx in unwashed cells was affected only slightly by noradrenaline and adrenaline. By contrast, K+ influx in cells which had been washed and incubated overnight before assay was stimulated 100-250% by these hormones. Half-maximal stimulation was at 2 X 10(-6) and 8 X 10(-6) M respectively. Replacement of plasma by a saline containing 5 X 10(-6) M adrenaline and noradrenaline resulted in high and stable K+ influx rates over a 6 h period. These results support the hypothesis that K+ influx in erythrocytes of freshly drawn blood is high as a result of stimulation by catecholamine hormones. Removal of the normal hormonal milieu, by washing of the cells, results in the rapid loss of K+ influx activity. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0022-0949 1477-9145 |
DOI: | 10.1242/jeb.101.1.93 |