A heterogeneous ouabain-ATPase interaction in mouse brain

Abstract

Unlike the ATPase in mouse kidney, which shows a simple pattern of ouabain interaction, the ATPase in mouse brain displays a heterogeneous interaction with the drug. Such heterogeniety is evident in the inhibition of NaKATPase by ouabain, in the binding of ouabain to brain tissue, and in the inhibition of digitoxin binding to brain by ouabain. The heterogeneous interaction can apparently be resolved into two components displaying K i (or K d) of 2×10 −7M and 1×10 −4M.The K i (or K d) in kidney was approximately 10 −4M. Possible mechanisms for the heterogeniety of the ouabain interaction with brain are discussed.