Inhibition by Δ1-Tetrahydrocannabinol of a Na+–K+ Transport ATPase from Rat Ileum. Preliminary Report

Abstract

The effect of Δ1-trans-tetrahydrocannabinol (THC) on ATPase activities of a microsomal fraction from rat ileum was measured. A concentration of 10−5 M completely abolished the stimulation due to sodium and potassium, whereas the activity of the Mg-ATPase was about 60% of the control. Even at concentrations found in blood after smoking one marihuana cigarette there was a slight inhibition of the Na+–K+-ATPase. The inhibition may be due to a specific binding or, more likely, to a general action of the THC on membranes.