ISSN:
1573-5168
Keywords:
lipid composition
;
(Na++K+)-ATPase
;
Na+-ATPase
;
microsomal Mg2+-ATPase
;
temperature acclimation
;
sea bass
;
gills
;
kidneys
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The response to cold of gill and kidney membrane lipid composition and microsomal (Na++K+)-ATPase, Na+-ATPase and Mg2+-ATPase activities in reared sea bass (Dicentrarchus labrax L.) was investigated. Fish acclimation was carried out according to the seasonal cycle from August to March. No cold-promoted increase in fatty acid unsaturation was shown in gill and kidney polar lipids and in total lipids of mitochondria and microsomes. In both tissues the (Na++K+)-ATPase exhibited positive compensation for cold acclimation whereas the Na+-ATPase displayed negative compensation. The Mg2+-ATPase showed no compensation in the gills and positive compensation in the kidneys. During cold acclimation the break in the Arrhenius plot of the (Na++K+)-ATPase decreased, whereas breaks of both the Na+-ATPase and the Mg2+-ATPase activities remained unchanged. The results indicate that the sea bass does not adopt membrane unsaturation as a cold-facing strategy. The cold-promoted enhancement of (Na++K+)-ATPase activity in osmoregulatory tissues may be advantageous to maintain efficient osmoregulation under thermodynamically unfavourable conditions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00004414
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