title: Effects of insulin treatment on endoneurial and systemic oxidative stress in relation to nerve conduction in streptozotocin-diabetic rats.
abstract: As increased oxidative stress is probably a pathogenetic factor in the development of diabetic complications, we studied nerve function and endogenous antioxidants in plasma, erythrocytes and sciatic nerve of untreated and insulin-treated streptozotocin-diabetic rats. After 18 weeks, the diabetes-induced sciatic nerve conduction velocity deficits were approximately 65% improved by insulin (P < 0.001). Plasma superoxide dismutase was significantly reduced in diabetes (P < 0.01); smaller decreases in plasma catalase and glutathione levels were observed. These changes were corrected by insulin treatment. In erythrocytes, decreased superoxide dismutase (P < 0.05) and increased total glutathione levels (P < 0.05) were found. All effects of diabetes, including a rise in plasma malonyldialdehyde (P < 0.05), were partially reversed by insulin treatment. In nervous tissue, diabetes caused increased catalase activity, uninfluenced by insulin (P < 0.05). Nerve superoxide dismutase and glutathione did not change. The data suggest that in diabetes, changes in systemic rather than endoneurial oxidative stress lead to nerve dysfunction.
authors.affiliation: Rudolf Magnus Institute for Neurosciences, Utrecht University, The Netherlands.
authors.forename: P S
authors.initials: PS
authors.lastname: van Dam
authors.forename: B
authors.initials: B
authors.lastname: Bravenboer
authors.forename: B S
authors.initials: BS
authors.lastname: van Asbeck
authors.forename: J F
authors.initials: JF
authors.lastname: van Oirschot
authors.forename: J J
authors.initials: JJ
authors.lastname: Marx
authors.forename: W H
authors.initials: WH
authors.lastname: Gispen
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D002374:Catalase / Q000097:blood; D003921:Diabetes Mellitus, Experimental; D005978:Glutathione / Q000097:blood; D007328:Insulin / Q000627:therapeutic use*; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D009431:Neural Conduction / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects*; D010525:Peripheral Nerves / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000097:blood; D013997:Time Factors
chemical_list: D000975:Antioxidants; D007328:Insulin; D008315:Malondialdehyde; D002374:Catalase; D013482:Superoxide Dismutase; D005978:Glutathione