Chelating Agents, Barbiturates, and Stimulation of Rat Brain Adenosinetriphosphatase

Publisher Website
Google Scholar
Abstract
The order of activity of barbiturates in stimulating the adenosinetriphosphatase activity (ATPase) of rat liver homogenates was thiopental >thiamylal >pentobarbital> phenobarbital >barbital. The ATPase of brain homogenates was not affected under the same conditions by the barbiturates, 2,4-dinitrophenol, chlortetracycline, or chloramphenicol. When ethylenediamine-tetra acetic acid (EDTA) was added either before or after homogenization, so that the final concentration of EDTA in the assay system was 10-4 [image], the ATPase of brain homogenates was considerably reduced and susceptible to stimulation by the above agents. The order of activity of the barbiturates in stimulating brain ATPase was pentobarbital > amytal > thiamylal >phenobarbital > barbital. Besides EDTA, ammoniatriacetic acid and 1,2-diaminocyclohexane-N,N'' -tetra acetic acid were effective in reducing brain ATPase and allowing subsequent stimulation.