Use of an Organic Chelating Agent in Histochemical Study of Alkaline Phosphatase Activation.

Abstract

Controlled inactivation of alkaline phosphatase in tissue sections was accomplished by chelation of the activating metallic component with ethylene diamine tetraacetic acid. The inactivated enzyme system of alcohol-fixed, paraffin-embedded rabbit kidney could subsequently be reactivated by a variety of bivalent metallic cations, including Mg, Co, Zn, Ca, Str, Ba, and Ni. The localization of enzyme activity in the tissue was the same regardless of the reactivating ion. Mn, Pb and Cd ions failed to reverse the inhibition but did not inhibit the active enzyme in the concns. used. The alkaline phosphatase of guinea pig and monkey kidney was inhibited by Pb and Cd in much lower concns.