Published 4 issues per year
ISSN Print: 2155-014X
ISSN Online: 2155-0158
Nitric Oxide as Possible Regulator of Energy-Dependent Ca2+ Transport in Mitochondria of Uterine Smooth Muscle
ABSTRACT
The influence of nitric oxide (NO) donor and precursor of the latter, namely sodium nitroprusside and sodium nitrite (100 mmol / l) on the energy-dependent Ca2+ transport in isolated from the rat myometrium was studied. Changes in Ca2+ concentration in the mitochondrial matrix were evaluated by spectrofluorimetry using Ca2+ -sensitive probe Fluo-4 AM. Mg2+ -ATP-dependent Ca2+ accumulation on mitochondria in the presence of succinate significantly stimulated nitric oxide. In particular, sodium nitroprusside (100 mmol / l) amplified the transport 1.6 times relative to the control values. NO effect became significant only if the preliminary incubation of mitochondria with the test compounds was performed. Since accumulation of Ca2+ in the presence of sodium nitroprusside was effectively suppressed by protonofore (CCCP) and ruthenium red (10 mmol / l), it was concluded that nitric oxide stimulates Ca2+ Uniporter in the inner mitochondrial membrane. Accumulation of Ca2+ By mitochondria in the presence of sodium nitroprusside was not sensitive to the action of cyclosporine A (5 mmol / l), a specific inhibitor of mitochondrial permeability transition pore opening. This indicates that the role of permeability transition pore is less important than calcium uniporter in the process of Ca2+ transport in the mitochondria subjected to the action of nitric oxide. Thus, nitric oxide stimulates the energy-dependent Ca2+ Accumulation by the myometrium mitochondria, which is mediated by the functioning of calcium uniporter of their inner membrane.
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Danylovych Yurii V., Danylovych Hanna V., Kolomiets Oksana V., Sviatnenko Marina D., Kosterin Sergiy O., Biochemical properties of H+-Ca2+-exchanger in the myometrium mitochondria, Current Research in Physiology, 5, 2022. Crossref