Regional histochemical aspects of xanthine oxidase activity in ischemic and reperfused small intestine of the rat.

The study describes regional changes of xanthine oxidase and succinate dehydrogenase activities as shown by the ischemic and reperfused small intestine of the rat. The results are obtained with enzyme histochemical methods, including densitometrical verifications, and are substantiated with biochemical enzyme determinations. The decrease of xanthine oxidase activity was best visible in the anoxic duodenum and jejunum, where the findings of histochemical enzyme determinations agreed with those achieved biochemically. The activities of succinate dehydrogenase as measured densitometrically may serve as a further control, considering also the typical intracellular distribution of the reaction products.