Deryagin OG, Gavrilova SA, Buravkov SV, Andrianov VV, Yafarova GG, Gainutdinov KL, Koshelev VB. [The role of ATP-dependent potassium channels and nitric oxide system in the neuroprotective effect of preconditioning].
Zh Nevrol Psikhiatr Im S S Korsakova 2018;
116:17-23. [PMID:
27905383 DOI:
10.17116/jnevro20161168217-23]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
AIM
To study a role of ATP-dependent potassium channels (K+ATP) in the neuroprotective effect of ischemic (IP) and pharmacological (PP) preconditioning and evaluate the dynamics of blood nitric oxide (NO) metabolites in cerebral ischemia.
MATERIAL AND METHODS
A model of ischemic stroke induced by the electrocoagulation of a middle cerebral artery (MCA) branch was used in male rats (n=86). Glibenclamide, a selective inhibitor of ATP-sensitive K+ channels, and diazoxide, a potassium channel activator, were used. IP and PP were performed 24 h before MCA occlusion. Blood concentrations of NO, NO3- and NO2-were measured 5, 24 and 72 h after occlusion.
RESULTS
IP decreased a lesion area by 37% (p<0/05) and the preliminary introduction ofglibenclamide levelled the effect of IP. A protective effect of PP was similar to that of IP. A decrease in oxygenated R-conformers of Hb-NO and a reverse increase in non-oxygenated T-conformers as well as NO3- и NO2-were noted 5h after MCA occlusion. In the first 24 h after MCA occlusion, contents of NO3- and NO2- returned to normal values. There were changes in the concentrations of Hb-NO complexes as well, with the predominance of R-conformers and minimal contents of T-conformers. Moreover, the correlations between K+ATP channel blockade and the decrease in serum NO3- and NO2 were found (p<0/03).
CONCLUSION
The neuroprotective effect of preconditioning is caused by the activation of K+ATP channels. An analysis of NO metabolite concentrations in the blood of rats with IP suggests that Hb-NO complexes belonging to R-conformers deposit and carry NO in tissues releasing NO accumulated via R→T transfer in conditions of ischemia.
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