ATP as a signaling molecule

The review considers the effects of extracellular ATP mediated by plasma membrane purinoreceptors in the cells of different tissues, in particular, myometrium. Recently published results suggest that cytosolic ATP may also play a role of signaling molecule, as indicated by the detection of the ATP receptor not only in the plasma membrane, but also in mitochondria. The authors have shown that ionized Ca2+ concentration in the rat myometrium mitochondria matrix is regulated by ATP at the absence of exogenous Ca2+. ATP concentration-dependent increase of [Ca2+]m was not affected in the presence of the mitochondrial Ca2+-uniporter blocker ruthenium red, the mitochondrial pore blocker cyclosporine A, or ATP synthase inhibitor oligomycin. It is assumed that cytosolic ATP could be a signaling molecule that regulates at least the Ca2+ ions exchange in mitochondria. Keywords: Ca2+ ions exchange, extracellular and cytosolic ATP, mitochondria, P2X7 receptors