Oxygen free radical effects in sciatic nerve in experimental diabetes.
We previously reported the presence of endoneurial hypoxia, ischemia, impairment of the blood-nerve barrier, and reduction of norepinephrine and 6-ketoprostaglandin F1 alpha in chronic streptozocin-induced diabetic neuropathy (SDN) and interpreted these findings as suggesting the involvement of oxygen free radicals (OFRs) but did not directly measure indices of OFR activity. In this study, we report on sciatic nerve conjugated dienes, hydroperoxides, norepinephrine, and malondialdehyde in SDN at 1, 4, and 12 mo in male Sprague-Dawley rats. Severe hyperglycemia was present throughout in diabetic rats. Conjugated dienes were consistently increased at all time points, hydroperoxides were consistently reduced, and malondialdehyde was not significantly different in diabetes compared with controls. These findings are consistent with increased OFR activity in experimental diabetes. It is necessary to monitor several indices of OFR activity in a metabolically active tissue such as the peripheral nerve.
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Department of Neurology, Mayo Clinic, Rochester, Minnesota.
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D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D003929:Diabetic Neuropathies / Q000503:physiopathology*; D005609:Free Radicals; D006442:Glycated Hemoglobin / Q000032:analysis; D008297:Male; D008315:Malondialdehyde / Q000032:analysis*; D009638:Norepinephrine / Q000032:analysis*; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D012584:Sciatic Nerve / Q000737:chemistry / Q000502:physiology / Q000503:physiopathology*; D013997:Time Factors
D001786:Blood Glucose; D005609:Free Radicals; D006442:Glycated Hemoglobin; D008315:Malondialdehyde; D009638:Norepinephrine