Oxygen free radicals decrease survival time of isolated rat hearts.
Effects of oxygen free radicals (OFR), enzymatically generated in the coronary circulation, were studied in isolated rat hearts retrogradely perfused with Krebs-Ringer solution. Control hearts (n = 6) functioned adequately for at least 5 hours. When rat hearts (n = 6) received xanthine oxidase (XOD) and hypoxanthine (HX) in order to generate OFR, survival time was reduced to 31 +/- 0.4 min (mean +/- SEM). Infusion of XOD (n = 8) or HX (n = 5) alone also reduced cardiac survival time, to 32 +/- 6 min and 139 +/- 23 min, respectively. When allopurinol (an inhibitor of XOD) was given together with XOD (n = 6), survival time (277 +/- 30 min) was similar to the control value. The production of OFR did not result in depressed coronary flow or heart rate, but reduced the aortic pulse pressure. OFR thus can depress cardiac function and may ultimately cause cardiac arrest.
Semb
A G
AG
Institute for Experimental Medical Research, University of Oslo, Norway.
Vaage
J
J
Laumann
J W
JW
Klingen
G
G
Ilebekk
A
A
D000818:Animals; D001011:Aorta / Q000502:physiology; D001794:Blood Pressure; D003326:Coronary Circulation; D005609:Free Radicals; D006339:Heart Rate; D007042:Hypoxanthines / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D014022:Tissue Survival; D014969:Xanthine Oxidase / Q000378:metabolism*
D005609:Free Radicals; D007042:Hypoxanthines; D014969:Xanthine Oxidase; D010100:Oxygen