Changes of ATPase activities in erythrocytes of rats with hypothalamic obesity.

Na,K- and Ca,Mg-ATPase activities in the membrane of red blood cells (RBC) were determined in glutamate treated obese rats (GOR). Both activities are related oppositely. In the obese rats the Na,K-ATPase is higher but the efficiency in maintenance of Na/K-ion concentration gradients is diminished. Ca,Mg-ATPase is decreased in GOR. Under the hypermetabolic condition of cold adaption the Na,K-ATPase activity decreases and the Ca,Mg-ATPase activity rises in both animal groups. The Na,K-ATPase activity in RBC-membranes is positively related to fat accumulation and age.