title: Activity attenuates skeletal muscle fiber damage after ischemia and reperfusion.
abstract: BACKGROUND
  In this investigation we aimed to determine whether: (1) physical activity protects rat skeletal muscle from ischemia/reperfusion (I/R) injury; and (2) continued activity after I/R improves the rate of healing.
  
  
  METHODS
  Rats were divided into sedentary or active (voluntary wheel running) groups. Active rats ran for 4 weeks before I/R or 4 weeks before plus 4 weeks after I/R.
  
  
  RESULTS
  Activity before I/R resulted in 73.2% less muscle damage (Evans blue dye inclusion). Sedentary and active rats had a similar decline in neural-evoked (∼ 99%) and directly stimulated (∼ 70%) in vivo muscle torque, and a similar reduction in junctophilin 1. Active rats produced 19% and 15% greater neural-evoked torque compared with sedentary rats at 14 and 28 days postinjury, respectively, although the rate of recovery appeared similar.
  
  
  CONCLUSIONS
  Activity protects against long-term muscle damage, but not short-term neural injury or excitation-contraction uncoupling. Continued activity neither accelerates nor hinders the rate of functional recovery.
authors: Extremity Trauma and Regenerative Medicine Research Program, United States Army Institute of Surgical Research, 3698 Chambers Pass, Fort Sam Houston, Texas, 78234-6315, USA.
authors: Thomas J
authors: TJ
authors: Walters
authors: Extremity Trauma and Regenerative Medicine Research Program, United States Army Institute of Surgical Research, 3698 Chambers Pass, Fort Sam Houston, Texas, 78234-6315, USA.
authors: Koyal
authors: K
authors: Garg
authors: Extremity Trauma and Regenerative Medicine Research Program, United States Army Institute of Surgical Research, 3698 Chambers Pass, Fort Sam Houston, Texas, 78234-6315, USA.
authors: Benjamin T
authors: BT
authors: Corona
mesh_terms: D000818:Animals; D001835:Body Weight; D004195:Disease Models, Animal; D007511:Ischemia / Q000150:complications* / Q000473:pathology; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000473:pathology* / Q000502:physiology*; D009135:Muscular Diseases / Q000209:etiology* / Q000473:pathology*; D010805:Physical Conditioning, Animal; D051381:Rats; D011917:Rats, Inbred Lew; D012038:Regeneration; D015427:Reperfusion Injury / Q000150:complications* / Q000473:pathology; D012420:Running; D018709:Statistics, Nonparametric; D019415:Torque
keywords: exercise; junctophilin 1; muscle injury; rats; trauma