[Increase in the sensitivity of the mitochondrial permeability transition pore opening to Ca2+ in heart of spontaneous hypertensive rat].

In experiments vitro on the mitochondria isolated from adult and spontaneous hypertensive rat hearts, we studied the sensitivity of the mitochondrial permeability transition pore (mPTP) opening to its natural inductor, Ca2+. We observed an increase in the sensitivity of mPTP opening to Ca2+ in the heart of spontaneous hypertensive rats because of a decrease in the threshold concentration of this ion required for organelles swelling by two orders of magnitude. It was shown that the classical inhibitor mPTP cyclosporin A (10(-5) mol/L) partially (54%) inhibited of mPTP opening in the heart of these animals, indicating that the presence in the heart of these animals of cyclosporin A-insensitive component of the mPTP. The results of our observations give reason to conclude that the hypertensive state of the organism is associated with mitochondrial dysfunction, which is characterized, in particular, by an increased sensitivity mPTP to Ca2+, eliciting a widespread tissue damage and diseases of the cardiovascular system, especially hypertension.