title: Changes in antioxidant enzymes and lipid peroxidation in extensor digitorum longus muscles of streptozotocin-diabetic rats may contribute to muscle atrophy.
abstract: We investigated muscle atrophy, major antioxidant enzymes and lipid peroxidation in the extensor digitorum longus (EDL, predominantly fast fibers) and soleus (predominantly slow fibers) muscle of streptozotocin-diabetic rats. Female Wistar rats were divided into a control (n = 5) and streptozotocin-induced diabetic group (n = 5). Eight weeks after diabetes induction the EDL and soleus muscles were removed and catalase (CAT), glutathione peroxidase (GPX) and superoxide dismutase activity (SOD), and thiobarbituric acid reactive substances (TBARS) levels measured. The CAT activity increased in both the EDL and soleus muscles of the diabetic rats (p < 0.01), whereas the GPX and SOD activities were increased only in the EDL muscle (p < 0.01 and p < 0.05). The TBARS levels were only increased in the EDL muscle of the diabetic rats (p < 0.01). Both muscles showed significant atrophy but the EDL muscle elicited the greatest atrophy. In conclusion, it appears that adaptive responses to oxidative stress were adequate in the soleus muscle, but not in the EDL muscle, of diabetic rats. Thus fast twitch muscle fibers may be more susceptible to oxidative stress than slow twitch muscle fibers and this may contribute to muscle atrophy under diabetic conditions.
authors.affiliation: Osaka Prefecture University Department of Physical Therapy 6-7-30 Habikino, Habikino Osaka 583-8555 Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Nonaka
authors.affiliation: Shujitsu Junior College Department of Living Science Okayama Japan.
authors.forename: S
authors.initials: S
authors.lastname: Une
authors.affiliation: Kibi International University Research Institute of Health Welfare Takahashi Japan.
authors.forename: N
authors.initials: N
authors.lastname: Tatsuta
authors.affiliation: Osaka Prefecture University Department of Physical Therapy 6-7-30 Habikino, Habikino Osaka 583-8555 Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ito
authors.affiliation: Kibi International University Research Institute of Health Welfare Takahashi Japan.
authors.forename: J
authors.initials: J
authors.lastname: Akiyama
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000201:enzymology* / Q000473:pathology; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism; D015227:Lipid Peroxidation; D018656:Muscle Fibers, Fast-Twitch / Q000201:enzymology / Q000473:pathology; D018657:Muscle Fibers, Slow-Twitch / Q000201:enzymology / Q000473:pathology; D018482:Muscle, Skeletal / Q000201:enzymology* / Q000473:pathology; D009133:Muscular Atrophy / Q000139:chemically induced / Q000201:enzymology* / Q000473:pathology; D018384:Oxidative Stress; D017208:Rats, Wistar; D013311:Streptozocin; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D000975:Antioxidants; D017392:Thiobarbituric Acid Reactive Substances; D013311:Streptozocin; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase
keywords: STZ-induced diabetes; antioxidant enzyme; extensor digitorum longus; lipid peroxidation; soleus