Different effects of aluminum upon carbonic anhydrases and Na+/K+-ATPase activities in rat

Aluminum (Al(III)) is a well established toxicant implicated as an etiological factor in several neuropathies. In this paper we report results regarding opposite effects produced by Al(III) on the activity of two enzymes utilized as models. While sodium-potassium ATPase (Na/K-ATPase) is strongly activated by Al(III) in a dose-effect dependent way, on the contrary, carbonic anhydrase (CA) is remarkably inhibited. The relevance of the metal speciation together with the enzymatic structural modification demonstrated by circular dichroism measurements could explain the observed modified enzymatic activities. In addition, a new experimental protocol for the preparation of Al(III) solutions at physiological pH useful in the standardization of Al(III) experimental toxicology is also proposed and discussed.