[Diazoxide-induced mitochondrial swelling in the rat myometrium as a consequence of the activation of the mitochondrial ATP-sensitive (K+)-channel].

In this paper we postulate, that mitochondria isolated from the rat myometrium undergo swelling in isoosmotic medium, which contains K+ (125 mM). This swelling was blocked by ATP (200 microM), but only when MgCl2 (1 mM) was present and observed when oligomycin, the inhibitor of FoF1-ATPase, was added to the incubation medium. Diazoxide (50 microM), activator of the mitochondrial ATP-sensitive potassium channel, removed ATP-induced blockade of swelling. Our results may prompt the presence of K+ transporter on the inner mitochondrial membrane, which possesses the features of the mitochondrial ATP-dependent potassium channel described earlier in mitochondria of the heart, liver, brain, retina, blood vessels and kidneys.