The intracellular calcium antagonist TMB-8 [8-(<i>NN</i>-diethylamino)octyl-3,4,5-trimethoxybenzoate] inhibits mitochondrial ATP production in rat thymocytes

Abstract

TMB-8 inhibited respiration of rat thymocytes and rat liver mitochondria, probably by inhibition of NADH dehydrogenase. TMB-8 markedly decreased both the cellular ATP concentration and the mitochondrial membrane potential in situ in thymocytes. These effects occurred at, or well below, the concentrations used in other systems to investigate the role of intracellular calcium pools in signalling events. We conclude that caution should be exercised in the interpretation of the effects of TMB-8.