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Information × Registration Number 0224U032399, 0120U102934 , R & D reports Title Reactive nitrogen and oxygen species as regulators of intracellular calcium homeostasis and contractile function of smooth muscles popup.stage_title Активні форми азоту і кисню як регулятори внутрішньоклітинного кальцієвого гомеостазу та скоротливої функції гладеньких м’язів Head Kosterin Serhii O., Доктор біологічних наук Registration Date 04-10-2024 Organization Palladin Institute of Biochemistry of the National Academy of Sciences of Ukraine popup.description2 Nitric oxide plays an important role in many physiological processes. In mitochondria, nitric oxide can regulate the activity of the respiratory and cation exchange systems in the inner membrane. The reciprocity of changes between the synthesis of NO in the mitochondria of the myometrium and the formation of ROS due to the inhibition of certain complexes of the respiratory chain and the stimulation of oxidative phosphorylation was established. Synthesis of NO by mitochondria is activated at physiological concentrations of exogenous Ca2+ and L-arginine, while no increase in ROS generation is observed. It was demonstrated that the activity of mitochondrial NO-synthase significantly depends on the level of energization of organelles and the intensity of exogenous Ca2+ entering to the matrix, it is inhibited by inhibitors of constitutive NO-synthases, Mg ions, calmodulin antagonists calmidazolium and trifluoperazine. The effect of calmodulin antagonists on the generation of ROS was the opposite: calmidozolium increased their formation, possibly by suppressing calmodulin-dependent electron transport in NO synthase and switching its NO synthase activity to oxidase, while trifluoperazine had almost no effect on the intensity of ROS production. Inhibition of mitochondrial NO-synthase activity by NG-nitro-L-arginine did not lead to the formation of ROS. Calix[4]arene C-956 stimulated the synthesis of NO in mitochondria and did not lead to the generation of ROS. In the presence of K+ channel inhibitors, nitric oxide synthesis by mitochondria was inhibited, but only 4-aminopyridine led to a significant increase in ROS generation. In the presence of glibenclamide, there was an increase in the hydrodynamic diameter of mitochondria, which proves the role of ATP-sensitive K+ channels in the regulation of their volume. Product Description popup.authors Danylovych Hanna V. Danylovuch Yurii V. Karakhim Serhii O. Chunikhin Oleksandr Yu. popup.nrat_date 2024-10-04 Close