Temperature Dependence of the Sodium Pump is Altered in the Cerebral Cortex of CCK2 Receptor-Deficient Mice

Previously we have shown that the temperature dependence of the sodium pump (Na+,K+-ATPase) is altered under different neuropathological conditions. In this study we compared temperature dependence of the Na+,K+-ATPase in the fronto-parietal cortex of CCK2 receptor-deficient (homo- and heterozygous) and normal (wild-type) mice. The Arrhenius plot for Na+,K+-ATPase from wild-type brain is non-linear with a breakpoint at 20.3 ± 0.4°C. In case of the brain cell membrane of CCK2 receptor-deficient mice (homo- and heterozygous) the breakpoint on Arrhenius plot was detected at 26.0 ± 1.1°C and 25.4 ± 0.4°C, respectively. The shift of the breakpoint on the Arrhenius plot established in CCK2 receptor-deficiency as well as in case of some other pathological conditions confirms that such kind of alteration in the Na+,K+-ATPase temperature dependence is likely related to the homeostatic adjustment of altered function of the sodium pump.