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% inhibition of Na+, K+-ATPase was 1.1 X 10(-6)M, 2 X 10(-7)M and 4.4 X 10(-7)M 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.