The effect of repeated treatment with electroconvulsive shock (ECS) on the turnover of cortical alpha 1-adrenoceptors in rats was measured using the N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ)-induced irreversible receptor inactivation method. Repeated treatment with ECS did not affect parameters (the synthesis rate constant r, the degradation rate constant k) of alpha 1-adrenoceptor turnover. Because increase in the density of alpha 1-adrenoceptors in the ECS-treated group disappears later during measurement of turnover, several calculation possibilities were discussed. The present data confirm that repeated treatment with ECS produces a short-lasting up-regulation of cortical alpha 1-adrenoceptors, but does not affect the turnover of this receptor type.