[Nitrogen monoxide and functional activity of large conductance Ca-activated potassium channels in coronary vessels in rats with limited motor activity].
The study was aimed at the detection of endothelial factors contribution and nitric monoxide produced by constitutional and inducible NO-synthase in regulation of Ca-activated potassium channels activity of high conductivity in immobilization stress. The experiments were conducted in isolated rat-female hearts after retrograde perfusion with Krebs-Henseleit solution bubbled with 95% O2, 5% CO2 at 37 degrees C. To study BK(Ca)-channels role in the regulation of coronary vessels tone and contractile myocardial function BK(Ca)-channel blocker tetraethylammonium (ImM/l concentration) (Sigma, USA) was added in perfused solution. The obtained results justify: firstly, the non-selective blockade of constitutional and inducible NO-synthase L-NAME accompanied by the reduction of coronary flow volume velocity to control values level in the group of animals underwent to stress; second, selective blocker of inducible NO-synthase S-methylisotiourea completely eliminates evoked by stress hypotonia of cardiac vessels and reduction of contractile activity of left ventricle in stressed rats; thirdly, stress reduces the functional activity of Ca-activated potassium channels and the removal of endothelium or blockade of nitric monoxide completely it restores.
Solodkov
A P
AP
Maĭorova
S S
SS
Lazuko
S S
SS
D000818:Animals; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology; D005260:Female; D007103:Immobilization; D066298:In Vitro Techniques; D015640:Ion Channel Gating; D007550:Isothiuronium / Q000031:analogs & derivatives / Q000494:pharmacology; D051036:Large-Conductance Calcium-Activated Potassium Channels / Q000502:physiology*; D009200:Myocardial Contraction; D009206:Myocardium / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000502:physiology*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors / Q000502:physiology; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors / Q000502:physiology; D026902:Potassium Channel Blockers / Q000494:pharmacology; D051381:Rats; D013315:Stress, Psychological / Q000378:metabolism* / Q000503:physiopathology; D019789:Tetraethylammonium / Q000494:pharmacology
D051036:Large-Conductance Calcium-Activated Potassium Channels; D026902:Potassium Channel Blockers; D007550:Isothiuronium; D019789:Tetraethylammonium; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C027744:S-methylisothiopseudouronium; D019331:NG-Nitroarginine Methyl Ester