Histochemical Localization of Xanthine Oxidase and Lipid Peroxides in Rat Myocytes
Date
1988-04
Authors
Simpson, Kathe Wold
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Abstract
Because xanthine oxidase (XO) induced H202 formation has been implicated as a source of free radicals and a cause of reperfusion injury, a histochemical method was developed to visualize the location of XO dependent production of H202 and the location of lipid peroxides within rat heart tissue at the light and electron microscope level. Diaminobenzidine (DAB), peroxidase (PX) and/or catalase (CAT), and xanthine were used to localize peroxides, causing formation of an osmo~hilic polymer at the location of peroxide production according to the following:
xanthine + 02 --(XO)--> urate + ยท02- + H202
H202 + DAB --(PX)--> H20 + DAB polymer; and
free radicals+ lipids--> lipid-OOH
lipid-OOH+ DAB -(CAT, PX)-> lipid-OH+ DAB polymer.
The results indicated XO activity was present in rat heart tissue only after an episode of global ischemia, and was concentrated in capillary endothelial cells and near capillaries in myocytes. Peroxidation of lipids in capillary and myocyte membranes was also apparent after an episode of ischemia, with deposition of DAB reaction product on surface and interior membranes. Membrane associated DAB was apparent in the presence and absence of exogenous xanthine, suggesting peroxidation of membrane lipids may also occur by other mechanisms.
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Keywords
muscle cells, xanthine oxidase, peroxidation
Citation
Simpson, K.W. (1988). Histochemical localization of xanthine oxidase and lipid peroxides in rat myocytes (Unpublished thesis). Southwest Texas State University, San Marcos, Texas.