General Physiology and Biophysics Vol.38, No.1, p.39–50, 2019
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Title: NO-synthase activity in mitochondria of uterus smooth muscle: identification and biochemical properties |
Author: Hanna V. Danylovych, Yuriy V. Danylovych, Maria O. Gulina, Tatyana V. Bohach, Sergiy O. Kosterin |
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Abstract: Information about the catalytic and kinetic properties of mitochondria NO-synthase from uterus smooth muscle is missing currently. According to the data on MitoTracker Orange CM-H2TMRos and 4-аmino-5-methylamino-2’,7’-difluorescein, diaminofluorescein-FM (DAF-FM) dye co-localization in uterine smooth muscle cells, presented in this paper, NO can be synthesized in their mitochondria. High activity of NO synthase requires the presence of substrates of respiration, L-arginine, Ca2+ and NADPH. It is established that the dependence of NO production on the concentration of L-arginine has a bell-shaped character with a maximum of 75 μM, and the apparent affinity constant for L-arginine is 28.9 ± 9.1 μM. The dependence of NO production on Ca2+ concentration has a maximum at 100-250 μM; the activation constant for Ca2+ is 44.4 ± 14.5 μM. The inhibitor of Ca2+ transport in mitochondria ruthenium red (RuR), as well as the inhibitor of NO-synthase NG-nitro-L-arginine (NA), reduces NO production. The biosynthesis of NO by mitochondria depends on its energized level: it is stimulated by the addition of respiration substrates, suppressed with specific inhibitors of the electron transport chain (rotenone and antimycin A) and carbonyl-cyanide 3-chlorophenylhydrazone (CCCP) protonophore.
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Keywords: Nitric oxide, Mitochondria, Calcium, Smooth muscle, Myometrium |
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Published online: 03-Feb-2019
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Year: 2019, Volume: 38, Issue: 1 |
Page From: 39, Page To: 50 |
doi:10.4149/gpb_2018034
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