Vanadate inhibition of rat cerebral cortex Na+, K+-ATPase during postnatal development

The Na⁺, K⁺-ATPase activity and its response to vanadate inhibition was investigated in cerebral cortex homogenates of 7-, 12- and 18-day-old rats. The enzyme was inhibited by vanadate in a dose-dependent manner in all these age groups. Furthermore, there was a different sensitivity towards vanadate during postnatal development; the concentration of V⁺⁵ needed for 50% inhibiton of Na⁺, K⁺-ATPase was 1.1×10^–6M, 2×10^–7M and 4.4×10^–7M for 7-, 12- and 18-day-old rats, respectively. It is suggested that the different sensitivity of Na⁺, K⁺-ATPase towards vanadate inhibition during postnatal development might be due to age-dependent changes in the ratio of various cell types.Special Issue dedicated to Dr. O. H. Lowry.