[Experimental study of injury on the small intestine in acute portal vein occlusion and the following restoration of portal vein flow in rats--free radicals in the small intestine and lipid peroxidation].
Free radicals in the small intestine were quantified by using an electron spin resonance spectrometer, and the amounts of TBA (thiobarbituric acid) reactants in arterial plasma, portal venous plasma and intestinal tissue were determined at the several stages. The effects of allopurinol, alpha-tocopherol, the simultaneous occlusion of superior mesenteric artery or the porto-jugular venous bypass, with the temporary occlusion of the portal vein, were also investigated. 1) Free radical concentration (mostly, semiquinones of CoQ and/or flavin in mitochondria) decreased with portal vein occlusion but showed a temporary increase at 10 sec after reperfusion. Allopurinol suppressed such temporary increase. 2) TBA reactants increased with the temporary occlusion of the portal vein. TBA reactants decreased during the portal vein occlusion with alpha-tocopherol and during reperfusion with allopurinol. Lipid peroxidation in the small intestine was also diminished by using the methods of simultaneous occlusion of the superior mesenteric artery or the porto-jugular venous bypass. In conclusion, there may be three sources for the generation of superoxide: the xanthine oxidase system, semiquinone radicals and paramagnetic metal irons. They may induce lipid a peroxidation, which accelerates the injury on the small intestine, in acute portal vein occlusion and the following restoration of portal vein flow in rats.
Ueda
S
S
Second Department of Surgery, Ehime University School of Medicine, Japan.
D000493:Allopurinol / Q000494:pharmacology; D000818:Animals; D003250:Constriction; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals; D007421:Intestine, Small / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D011169:Portal Vein; D051381:Rats; D011919:Rats, Inbred Strains; D015427:Reperfusion Injury / Q000378:metabolism*; D013481:Superoxides / Q000378:metabolism; D013858:Thiobarbiturates / Q000097:blood / Q000378:metabolism; D014810:Vitamin E / Q000494:pharmacology
D005609:Free Radicals; D013858:Thiobarbiturates; D013481:Superoxides; D014810:Vitamin E; D000493:Allopurinol; C029684:thiobarbituric acid