[Brain and kidney, Na, K-ATPase activation in the rat in adaptation to cold]

The activity of Na,K-ATPase of the rat brain and kidney is 1.5--2-fold as increased during intermittent and prolonged (16 weeks) adaptation to cold, without changes in the enzyme affinity to ATP. It is suggested that adaptive increase in the power of the Na pump, triidothyronine-dependent in the kidneys and triiodothyronine-independent in the brain, ensures elevation in thermal production to body cooling.