Xanthine oxidase has been established as an important source of oxygen free radicals in ischemia-reperfusion injury. It has been localized in many different tissues such as heart and intestine, but it has not yet been localized in the eye. Xanthine oxidase was detected using immunohistochemistry on paraformaldehyde/glutaraldehyde fixed cryosections. Antibodies used included rabbit antibovine xanthine oxidase antibody and rabbit antihuman xanthine oxidase antibody. Xanthine oxidase was detected in the capillary endothelium cells of blood vessels in the retina of bovine and post mortem human eyes. Whole mount preparation of human retinas showed xanthine oxidase present throughout the small capillary network. Furthermore, whole mounts showed that xanthine oxidase was present in cones. This was confirmed by using mouse anticalbindin antibody for co-labelling. It is possible that xanthine oxidase can be a source of oxidative damage in the retina following ischemia-reperfusion injury.
Bibliographical noteFunding Information:
This work was supported by a grant from the National Eye Institute (EY 08818) and by the Air Force Office of Scientific Research, Air Force Systems Command, USAF, under grant numbers 90-0327 and 93-NL036. The US government is authorized to reproduce and distribute reprints for governmental purposes notwithstanding any copyright notation hereon. Dr. van Kuijk is a Research to Prevent Blindness William & Mary Greve Scholar. The authors thank G. Bulkley for the gift of the antibovine xanthine oxidase antibody and T. Adachi and K. Hirano for their generous gift of the antihuman xanthine oxidase antibody. We also wish to thank Anne Rusoff, Christine Curcio, and Anita Hendrickson for helpful discussions. Frances Lefcort is acknowledged for assistance with the double labelling experiment. C & P Packing Company in Livingston, MT is acknowledged for making bovine eyes available and the Montana Eye Bank in Missoula MT, for making human eyes available for this study.
- Free radicals
- Xanthine oxidase