title: Xanthine oxidase in rabbit plasma after application of a bovine milk preparation to small intestine.
abstract: The absorption of xanthine oxidase into the bloodstream was studied in rabbits given a milk/cream preparation, fortified with 130 U bovine milk xanthine oxidase or the milk/cream preparation alone (control). The preparations were injected trans-abdominally into the intestines. The rise of plasma xanthine oxidase/dehydrogenase activity was studied with a radioenzymatic assay with and without NAD+. In rabbits, which received the fortified mixture, the plasma xanthine oxidase increase in 8 h was six times more than the increase in control animals (P less than 0.001). In both groups plasma xanthine dehydrogenase activity increased 3-4 times (P less than 0.001), without a significant difference between the two groups. We estimate that only 0.003%, or about 3 micrograms, of the xanthine oxidase added, is absorbed as an active enzyme from the intestine.
mesh_terms: D000818:Animals; D005260:Female; D007408:Intestinal Absorption; D008892:Milk / Q000378:metabolism*; D011817:Rabbits; D013997:Time Factors; D014968:Xanthine Dehydrogenase / Q000097:blood; D014969:Xanthine Oxidase / Q000097:blood / Q000378:metabolism*
chemical_list: D014968:Xanthine Dehydrogenase; D014969:Xanthine Oxidase