Strutyns'ka N A, Semenykhina O M, Chorna S V, Vavilova H L, Sahach V F
Fiziol Zh (1994). 2011;57(6):3-14.
In experiments in vivo and in vitro on the mitochondria isolated from adult and old rat hearts, we studied the effects of a donor of hydrogen sulfide (H2S), NaHS, and H2S biosynthesis substrate, L-cysteine, on the sensitivity of the mitochondrial permeability transition pore (mPTP) opening to its natural inductor, Ca(2+). We found that NaHS (10(-12) to 10(-4) mol/l) influenced mitochondrial swelling in a concentration-dependent manner. It was also demonstrated that the addition of NaHS (10(-12) to 10(-8) mol/l) to the calcium-free medium resulted in moderate a swelling of mitochondria from both adult and old rat hearts. At 10(-10) mol/l NaHS, the maximal values of the mitochondrial swelling observed in both adult and old hearts were 11 and 15 ,%, respectively. A specific inhibitor of KATP channels, 5-hydroxydecanoate (5-HD; 10(-4) mol/l) decreased the mitochondrial swelling in the presence of NaHS (10)-10) mol/l), which can be indicative of the contribution of these channels to the calcium-independent conductance of the mitochondrial membranes in the rat hearts. The H2S donor NaHS used in physiological concentrations (10(-6), 10(-5) and 5 10(-5) mol/l) exerted the inhibiting effect on the Ca(2+)-induced mPTP opening in adult hearts (corresponding values of such effect were 31, 76, and 77%, respectively), while in old hearts the protector effect of NaHS was observed only at its concentration of 10(-5) mol/l. Therefore, the donor of H2S used in the tested concentrations (10(-12) to 10(-4) mol/l) exerted ambiguous effect on the mitochondrial swelling: low concentrations of NaHS (10(-12) to 10(-8) mol/l) increased the mitochondrial swelling, while its physiological concentrations (10(-6) to 5 10(-5) mol/l) exerted the protective effect on Ca(2+)-induced mitochondrial swelling in adult and old hearts. Pre-incubation of isolated mitochondria with 5-HD (10(-4) mol/l) resulted in a decrease in the protective effect evoked by NaHS (10(-5) mol/l) on Ca(2+)-induced mPTP opening, which is indicative of the possible involvement of mitochondrial KATP-channels in the H2S-dependent inhibition of mPTP formation in both adult and old rat hearts. In experiments in vivo, single intraperitoneal injections of both NaHS (10(4) mol/kg) and L-cysteine ((10(-3) mol/kg) resulted in a decrease in the sensitivity of mPTP to its inductor Ca(2+) in adult and old rat hearts. The action of L-cysteine, as compared with that of NaHS, was more effective in prevention of Ca(2+)-induced mitochondrial swelling. We observed a rise in Ca(2+) concentration by one order of magnitude, which evoked the mitochondrial swelling in adult and old hearts. In experiments in vivo in which we used a specific blocker ofcystathionine-g-lyase, propargylglycine (10(-4) mol/kg) that is involved in the synthesis of H2S, we observed an increase in the sensitivity of mPTP opening in old hearts because of a decrease in the threshold Ca(2+) concentration required for mitochondrial swelling by two orders of magnitude. We demonstrate the involvement of endogenous H2S in the control of mPTP formation in adult and old hearts. Our studies are indicative of the involvement of H2S in modulation of changes in the permeability of mitochondrial membranes, which can be an important regulatory factor in the development of cardiovascular diseases.
在对成年和老年大鼠心脏分离出的线粒体进行的体内和体外实验中，我们研究了硫化氢（H₂S）供体硫氢化钠（NaHS）和H₂S生物合成底物L-半胱氨酸对线粒体通透性转换孔（mPTP）开放对其天然诱导剂Ca²⁺敏感性的影响。我们发现，NaHS（10⁻¹²至10⁻⁴ mol/L）以浓度依赖性方式影响线粒体肿胀。还证明，在无钙培养基中添加NaHS（10⁻¹²至10⁻⁸ mol/L）会导致成年和老年大鼠心脏的线粒体适度肿胀。在10⁻¹⁰ mol/L NaHS时，成年和老年心脏中观察到的线粒体肿胀最大值分别为11%和15%。KATP通道的特异性抑制剂5-羟基癸酸（5-HD；10⁻⁴ mol/L）在存在NaHS（10⁻¹⁰ mol/L）时可减少线粒体肿胀，这表明这些通道对大鼠心脏线粒体膜的钙非依赖性电导有贡献。生理浓度（10⁻⁶、10⁻⁵和5×10⁻⁵ mol/L）的H₂S供体NaHS对成年心脏中Ca²⁺诱导的mPTP开放具有抑制作用（相应的抑制效果值分别为31%、76%和77%），而在老年心脏中，仅在10⁻⁵ mol/L浓度的NaHS时观察到保护作用。因此，测试浓度（10⁻¹²至10⁻⁴ mol/L）的H₂S供体对线粒体肿胀产生了模糊的影响：低浓度的NaHS（10⁻¹²至10⁻⁸ mol/L）增加了线粒体肿胀，而其生理浓度（10⁻⁶至5×10⁻⁵ mol/L）对成年和老年心脏中Ca²⁺诱导的线粒体肿胀具有保护作用。用5-HD（10⁻⁴ mol/L）预孵育分离的线粒体导致NaHS（10⁻⁵ mol/L）对Ca²⁺诱导的mPTP开放所产生的保护作用降低，这表明线粒体KATP通道可能参与了成年和老年大鼠心脏中H₂S依赖性mPTP形成的抑制。在体内实验中，单次腹腔注射NaHS（10⁻⁴ mol/kg）和L-半胱氨酸（10⁻³ mol/kg）均导致成年和老年大鼠心脏中mPTP对其诱导剂Ca²⁺的敏感性降低。与NaHS相比，L-半胱氨酸在预防Ca²⁺诱导的线粒体肿胀方面更有效。我们观察到Ca²⁺浓度升高一个数量级，这会引起成年和老年心脏的线粒体肿胀。在体内实验中，我们使用了参与H₂S合成的胱硫醚-γ-裂解酶的特异性阻滞剂炔丙基甘氨酸（10⁻⁴ mol/kg），我们观察到老年心脏中mPTP开放的敏感性增加，因为线粒体肿胀所需的阈值Ca²⁺浓度降低了两个数量级。我们证明内源性H₂S参与了成年和老年心脏中mPTP形成的控制。我们的研究表明H₂S参与了线粒体膜通透性变化的调节，这可能是心血管疾病发展中的一个重要调节因素。
