[Cyclosporin A-sensitive mitochondrial pore as a target of cardioprotective action of hydrogen sulfide donor].

In experiments on a model of ischemia-reperfusion in Langendorff isolated rat hearts and isolated mitochondria we studied the role of hydrogen sulfide donor - sodium hydrosulfide (NaHS, 7.4 mg/kg) in modulating the sensitivity ofmitochondrial permeability transition pore opening. It was shown that NaHS increased the reserves of rat myocardium and had cardioprotective effects from ischemia-reperfusion.

[Effect of precursors and modulators of coenzyme Q biosynthesis on the heart mitochondria function in aged rats].

Our research demonstrate that ageing leads to changes in activity of electron-transporting enzyme complexes in myocardial mitochondria of old rats and to increased sensitivity of mitochondrial permeability transition pore to inductors of its opening--Ca2+ and phenylarsine oxide. We also observed activation of lipid and protein free-radical peroxidation processes. Administration of a complex of biologically active substances that included precursors and modulators of coenzyme Q biosynthesis (alpha-tocopherol acetate, 4-hydroxybenzoic acid, and methionine) we observed the increase in coenzyme Q content, correction of functional activity of mitochondrial electron-transport chain enzyme complexes, the decrease in intensivity of lipid and protein free-radical peroxidation in the heart and the decrease in sensitivity of mitochondrial permeability transition pore to inductors of its opening.

[No-dependent modulation of the sensitivity of the mitochondrial permeability transition pore opening under ischemia-reperfusion of the isolated heart].

The role of nitric oxide (NO) in modulation of sensitivity ofmitochondnal permeability transition pore (MPTP) opening under exposure to calcium as inductor was studied in experiments on the isolated heart (on Langendorff) and isolated mitochondria. The MPTP opening was studied on the hearts under ischemia-reperfusion and of the mitochondrial calcium loading. We investigated the degree ofreperfusional injury of the heart functional state after preliminary administration of the classic inhibitor of MPTP opening: cyclosporin A, the nitroprussid sodium salt as NO donor, NO-synthase (NOS) inhibitors such as L-NMMA and aminoguanidin to perfusional solution, and also the influence of Ca+ in the range of concentrations (10(-8)-10(-4) M) on the mitochondrial swelling under its preincubation with L-NMMA (10(-4) M).

[Properties of the smooth muscle cell endoplasmic reticulum calcium pump].

In experiments with 45Ca2+ conducted on digitonin-treated (0.1 mg/ml) myometrium cells suspension, the properties of ruthenium red-insensitive, oxalate- or phosphate-stimulated and thapsigargin- or cyclopiasonic acid-suppressed Mg2+, ATP-dependent calcium pump of myometrium sarcoplasmic reticulum was studied. The Ca2+ accumulation increased linearly in time up to 10 min, the average initial rate was 80-130 pmol Ca2+/10(6) cells per min.