[Hyperthyroidism and the transmembrane potential of rat liver mitochondria]

Transmembrane potential of liver mitochondria in hyperthyroid rats was higher than that in euthyroid animals. Besides, a lower resistance to Ca2+ of the system responsible for the maintenance of the transmembrane potential was observed in the preparations from hyperthyroid rats. This was manifested in a decrease of the calcium dose required for the decay of the transmembrane potential and in a shorter period of Ca2+ retention by mitochondria. The observed decrease in the resistance to Ca2+ ions of the potential-maintaining system in hyperthyroid mitochondria is supposed to be determined by the increased activity of mitochondrial endogenous phospholipase.