Inhibitory effects of vanadium pentoxide on respiration of rat liver mitochondria

The bioenergetic functions of liver mitochondria were studied following the acute and chronic exposure of rats to vanadium pentoxide via respiratory tract. The mitochondrial respiration with glutamate or succinate as substrate was inhibited significantly when compared to the control animals. No inhibition was found with ascorbate. The same effects were observed in vitro. Vanadium (V) was responsible for these inhibitory effects. It is postulated that significant amounts of vanadate are accumulated in the intermembrane space of liver mitochondria of the exposed rats. The process of "detoxification" by reduction of vanadate in the tissue may be insufficient to prevent the deleterious action of this compound on liver mitochondria.