[The relationship between Na overload and Na/H exchange--a study in the isolated isovolumic rat hearts].
Thirty min after stabilization perfusion with oxygenated buffer, hearts were divided in four groups: (1) CONTROL GROUP: 75 min. of aerobic perfusion; (2) Low flow anoxia group: 45 min. of low flow anoxic perfusion (95% N2:5%CO2, 0.15 ml/min.) followed by 30 min. of aerobic perfusion; (3) Ouabain group: protocol same as (2), except that ouabain (200 mumol/L) was added to anoxic perfusate during low flow anoxia; (4) Ouabain+Amiloride group: protocol same as (3) except that amiloride (0.5 mmol/I) was added to perfusate during low flow anoxia. Compared with the low flow anoxia group, ouabain resulted in an additional increase in Na during reperfusion accompanied with a depressed ventricular function. The deleterious effects of ouabain could be significantly combatted by amiloride. It is concluded that a decrease in Na/K ATPase activity may contribute to Na gain in reperfused myocardium, the mechanism of which might result from stimulation of Na/H exchange.
Zhao
T C
TC
Department of Pathophysiology, Beijing Medical University.
Shi
A Y
AY
D000818:Animals; D006859:Hydrogen / Q000378:metabolism*; D066298:In Vitro Techniques; D017136:Ion Transport; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism; D017494:Proton Pumps / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012964:Sodium / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism / Q000502:physiology
D017494:Proton Pumps; D006859:Hydrogen; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase