The effects of thermal acclimation upon ion transport in erythrocytes

The different components of ⁸⁶Rb⁺ influx (a marker for K⁺ influx) were measured in erythrocytes of 10°C and 30°C-acclimated carp. Passive influx was similar in both acclimation groups and was stimulated by increased temperature. The active and facilitated components of ⁸⁶Rb⁺ influx plateaued above 15°C in 10°C-acclimated carp and above 25°C in 30°C-acclimated carp. The furosemide-sensitive component, an ill-defined facilitated mechanism, was particularly affected by high temperatures. The influx rates of each acclimation group at 50°C were almost identical but at higher temperatures, the influx rates for 30°C-acclimated carp were substantially greater than for the 10°C-acclimated fish.