title: Heat stress attenuates skeletal muscle atrophy of extensor digitorum longus in streptozotocin-induced diabetic rats.
abstract: To investigate whether heat stress attenuates skeletal muscle atrophy of the extensor digitorum longus (EDL) muscle in streptozotocin-induced diabetic rats, 12-week-old male Wistar rats were randomly assigned to four groups (n = 6 per group): control (Con), heat stress (HS), diabetes mellitus (DM), and diabetes mellitus/heat stress (DM + HS). Diabetes was induced by intraperitoneal injection of streptozotocin (50 mg/kg). Heat stress was induced in the HS and DM + HS groups by immersion of the lower half of the body in hot water at 42 °C for 30 min; it was initiated 7 days after injection of streptozotocin, and was performed once a day, five times a week for 3 weeks. The muscle fiber cross-sectional area of EDL muscles from diabetic and non-diabetic rats was determined; heat stress protein (HSP) 72 and HSP25 expression levels were also analyzed by western blotting. Diabetes-induced muscle fiber atrophy was attenuated upon heat stress treatment in diabetic rats. HSP72 and HSP25 expression was upregulated in the DM + HS group compared with the DM group. Our findings suggest that heat stress attenuates atrophy of the EDL muscle by upregulating HSP72 and HSP25 expression.
authors.affiliation: Department of Physical Therapy, Osaka Prefecture University , Osaka , Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nonaka
authors.affiliation: Department of Living Science, Shujitsu Junior College , Okayama , Japan.
authors.forename: S
authors.initials: S
authors.lastname: Une
authors.affiliation: Department of Physical Therapy, Kibi International University , Takahashi , Japan.
authors.forename: J
authors.initials: J
authors.lastname: Akiyama
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000150:complications* / Q000473:pathology; D055551:HSP27 Heat-Shock Proteins / Q000378:metabolism; D050884:HSP72 Heat-Shock Proteins / Q000378:metabolism; D018882:Heat Stress Disorders / Q000150:complications* / Q000378:metabolism / Q000473:pathology; D018869:Heat-Shock Response; D006358:Hot Temperature; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology*; D009133:Muscular Atrophy / Q000209:etiology / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D017208:Rats, Wistar; D013997:Time Factors
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D055551:HSP27 Heat-Shock Proteins; D050884:HSP72 Heat-Shock Proteins; C486114:Hspb1 protein, rat
keywords: HSP25; HSP72; extensor digitorum longus muscle; heat stress; skeletal muscle atrophy; streptozotocin-induced diabetes