SINOPSIS

In vitro experiments on the mitochondria isolated from adult normotensive and spontaneously hypertensive rat hearts, an increased sensitivity of mitochondrial permeability transition pore (mPTP) to Ca²⁺, its natural inducer, has been revealed. In spontaneously hypertensive rats, it is evoked by the reduction of active ion concentration by two orders, which causes organelle swelling. Calcium-induced swelling of the mitochondria isolated from the normotensive rats (control) is completely prevented by cyclosporin A (10⁻⁵ mol/l), a natural mPTP inhibitor, while in spontaneously hypertensive rats, it is prevented only partially (by 54%), indicating the presence of cyclosporin A-insensitive mPTP component. The results obtained give reason to conclude that hypertension is associated with mitochondrial dysfunction, characterized, in particular, by increased mPTP sensitivity to Ca²⁺, which may elicit widespread tissue damage, accompanying diseases of the cardiovascular system, especially hypertension.