[Regulation of thyroid hormones of the interaction of mitochondria with low-molecular weight cytoplasmic mediators, induced by phosphate- dependent transport of K+ and H+ ions through the mitochondrial inner membrane].

In vivo thyroid hormones control the binding to mitochondria of low molecular weight water-soluble cytoplasmic mediators that are capable to induce oxidative phosphorylation uncoupling, by increasing the sensitivity of mitochondria to the effects of these mediators. In hyperthyroid rat liver mitochondria cytoplasmic mediators stimulate the phosphate-dependent transport of K+ and H+ in a greater degree than in liver mitochondria of control rats. The increase in the oxidative phosphorylation uncoupling by cytoplasmic mediators is one of mechanisms of thermogenesis stimulation by thyroid hormones.

[Regulation of oxidative phosphorylation, K+ ions transport and the volume of mitochondrial matrix by cytoplasmic glycopeptide and Ca2+ ions].

A thermostable low molecular weight glycopeptide containing syalic acids, which uncouples mitochondrial oxidative phosphorylation, has been detected, isolated and purified from rat liver cytoplasm. In the presence of the glycopeptide, oxidative phosphorylation in rat liver mitochondria is uncoupled by low physiological concentrations of Ca2+, which otherwise do not have any appreciable effect on the mitochondria. Oxidative phosphorylation uncoupling by the glycopeptide is accompanied by an increase of the mitochondrial volume.

[Induction of electrogenic phosphate transport through the mitochondrial membrane by a thermostable cytoplasmic factor in hyperthyroidism].

Addition of a thermostable cytoplasmic fraction leads to the uncoupling of oxidative phosphorylation of the mitochondria. In hyperthyrosis such an effect manifests itself more powerfully than in the control. Addition of the thermostable cytoplasmic fraction induces electrogenic phosphate transport via the mitochondrial membrane.

[Regulation of pyruvate transport in mitochondria by thyroid hormones].

During thyroidectomy, the stimulating action of the catalytic amounts of a thermostable fraction of rat liver and diaphragm cytoplasm on Ca2+ transport in mitochondria, which indicates the decrease of the activity of an insulin-dependent cytoplasmic regulator (IDR) in insulin target organs. Thyroidectomized rats also manifested a decrease in blood insulin and glucose concentrations. Administration of the physiological doses of thyroxine produced an increase in both blood glucose concentration and IDR activity in the liver and diaphragm of thyroidectomized rats.