Xanthine oxido-reductase activity in ischemic human and rat intestine |
| |
Authors: | Bianciardi Paola Scorza Roberto Ghilardi Giorgio Samaja Michele |
| |
Institution: |
a Dipartimento di Medicina, Chirurgia e Odontoiatria University of Milan, San Paolo Hospital via di Rudini' 8-20142 Milano Italy. |
| |
Abstract: | We measured time course and extent of xanthine dehydrogenase (XD) to xanthine oxidase (XO) conversion in ischemic human and rat intestine. To model normothermic no-flow ischemia, we incubated fresh biopsies for 0, 2, 4, 8 and 16 h. At Formula: See Text] XO was less in humans than in rats Formula: See Text] while XD was essentially the same Formula: See Text] After 16 h incubation at 37°C, there was no appreciable XD-to-XO conversion and no change in neither XO nor XD activity in human intestine. In contrast, the rat intestine had Formula: See Text] ratio doubled in the first 2 h and then maintained that value until Formula: See Text] In conclusion, no XO-to-XD conversion was appreciable after 16 h no-flow normothermic ischemia in human intestine; in contrast, XO activity in rats increased sharply after the onset of ischemia. An immunohistochemical labelling study shows that, whereas Formula: See Text] expression in liver tissue is localised in both hepatocytes and endothelial cells, in the intestine that expression is mostly localised in epithelial cells. We conclude that XO may be considered as a major source of reactive oxygen species in rats but not in humans. |
| |
Keywords: | Free radicals Xanthine oxidase No-flow ischemia Reperfusion |
本文献已被 InformaWorld PubMed 等数据库收录! |
|