Role of ion fluxes in hydrogen peroxide pulmonary vasoconstriction.
Hydrogen peroxide injected into the inflow cannula of isolated ventilated rat lungs produced a dose-dependent vasoconstriction in the range 0.25-10 mM, with maximum response between 2-5 mM. The effects of H2O2 can be influenced by ionophores or specific inhibitors of ionic channels or pumps. A key role is played by sodium ions which govern the subsequent inflow or outflow of calcium, an ion mediating the vasoconstriction. A physiological role for H2O2 generated by NADPH oxidase is postulated.
Wilhelm
J
J
Department of Medical Chemistry and Biochemistry, Charles University, Prague, Czech Republic.
Herget
J
J
D000818:Animals; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D066298:In Vitro Techniques; D007473:Ion Channels / Q000187:drug effects / Q000378:metabolism*; D008168:Lung / Q000098:blood supply* / Q000187:drug effects / Q000378:metabolism; D008297:Male; D010477:Perfusion; D051381:Rats; D017208:Rats, Wistar; D014661:Vasoconstriction / Q000187:drug effects*
D007473:Ion Channels; D006861:Hydrogen Peroxide