Absence of xanthine oxidase or xanthine dehydrogenase in the rabbit myocardium.
We directly measured the activity of the enzymes xanthine oxidase and xanthine dehydrogenase in rabbit and rat hearts, using a sensitive radiochemical assay. Neither xanthine oxidase activity nor xanthine dehydrogenase activity was detected in the rabbit heart. In the rat heart, xanthine oxidase activity was 9.1 +/- 0.5 mIU per gram wet weight and xanthine dehydrogenase activity was 53.0 +/- 1.9 mIU per gram wet weight. These results argue against the involvement of the xanthine oxidase/xanthine dehydrogenase system as a mechanism of tissue injury in the rabbit heart, and suggest that the ability of allopurinol to protect the rabbit heart against hypoxic or ischemic damage must be due to a mechanism other than inhibition of these enzymes.
Grum
C M
CM
Ragsdale
R A
RA
Ketai
L H
LH
Shlafer
M
M
D000818:Animals; D007658:Ketone Oxidoreductases / Q000378:metabolism*; D009206:Myocardium / Q000201:enzymology*; D011817:Rabbits / Q000378:metabolism*; D051381:Rats; D013045:Species Specificity; D014968:Xanthine Dehydrogenase / Q000378:metabolism*; D014969:Xanthine Oxidase / Q000378:metabolism*
D014968:Xanthine Dehydrogenase; D014969:Xanthine Oxidase; D007658:Ketone Oxidoreductases