Contrasting effects of temperature acclimation on mechanisms of ionic regulation in a eurythermic and a stenothermic species of freshwater fish (Rutilus rutilus and Salvelinus alpinus)

SCHWARZBAUM PJ, WIESER W, NIEDERSTAETTER H

COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. A: COMPARATIVE PHYSIOLOGY.

Elsevier

Año: 1991 p. 483 - 489

0300-9629

Eff&s of temperature on aspects of ionic regulation in kidney and gills of Rut&s rut&s and Saluelinus a$inus were studied by a variety of techniques. 2. In the kidney tissue of coid acclimated R. rut&s, the maximal number of binding sites per mg protein (Bmax) and the activity of Na+, K+-ATPase, as well as tissue respiration increased significantly, whereas in S. alpinus no changes in these variables were observed. On the other hand, 86Rb+ efllux from kidney tissue was unaffected by temperature in R. rutiius, whereas it was about 60% lower in S. alpinus acclimated and measured at YC, than in specimens acclimated and measured at 15°C. 3. In both species, the activity of gill Na+, K+-ATPase was 1.5. to 2-fold higher in cold-acclimated than in warm-acclimated fish although Bmax decreased in R. r&us, but remained constant in S. alpinus. 4, Problems of ionic regulation are discussed with regard to differences in temperature sensitivity of passive flows and primary active transport of ions in the t&sues of poikilothermic animals.