Free radical mediated injuries after coronary artery occlusion.
The left descending coronary artery (LAD) of mongrel dogs was ligated for one month to evaluate the effect of a dihydroquinoline-type antioxidant (MTDQ-DA) during the healing process of myocardial infarction. Thirty animals were divided into three groups: I) control animals (10 dogs) were treated with saline infusion during operation and postoperative days; II) 10 dogs were treated with intravenous MTDQ-DA during the operation followed by postoperative oral treatment, and III) 10 animals were treated with preoperative and postoperative oral treatment plus intraoperative MTDQ-DA infusion. The antioxidant effects were evaluated by measurements of the lipid peroxidation and product malondialdehyde (MDA) and of endogenous scavengers: reduced glutathione (GSH) and superoxide dismutase (SOD) in the ischemic and in intact areas. Ultrathin sections were investigated by JEOL 100 C electron microscope. Elevation of lipid peroxidation (LPO) was present in each group. The most remarkable changes were seen in the control ischemic areas (152 +/- 6.7%). GSH was depleted in the infarcted areas of the control hearts (60 +/- 5.6%), in the antioxidant treated animals this thiol compound was only slightly decreased (81 +/- 5.6%). SOD activity showed a sharp decline (group I) in both ischemic (52 +/- 8.3 U/g) and non-ischemic parts of the left ventricle (78 +/- 7 U/g). After MTDQ-DA treatment (groups II, III) SOD activity diminished only in the ischemic area (83 +/- 8.5 U/g); other parts showed normal (123 +/- 7.2 U/g) activity. According to ultrastructural examinations, MTDQ-DA diminished the degree of structural injury.
Röth
E
E
Department of Experimental Surgery, University Medical School of Pécs, Hungary.
Török
B
B
Kelemen
D
D
Pollák
S
S
D000818:Animals; D003327:Coronary Disease / Q000209:etiology* / Q000473:pathology; D004285:Dogs; D005260:Female; D005609:Free Radicals; D005978:Glutathione / Q000032:analysis; D015227:Lipid Peroxidation; D008297:Male; D008315:Malondialdehyde / Q000032:analysis; D009206:Myocardium / Q000378:metabolism / Q000473:pathology*; D011292:Premedication; D011804:Quinolines / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000032:analysis; D013997:Time Factors; D014945:Wound Healing / Q000187:drug effects*
D005609:Free Radicals; D011804:Quinolines; D008315:Malondialdehyde; C044964:6,6'-methylenebis(2,2-dimethyl-4-methanesulfonic acid-1,2-dihydroquinoline); D013482:Superoxide Dismutase; D005978:Glutathione