The role of ascorbic acid and exercise in chronic ischemia of skeletal muscle in rats.
This study was designed to investigate the effects of peripheral arterial insufficiency, exercise, and vitamin C administration on muscle performance, cross-sectional area, and ultrastructural morphology in extensor digitorum longus (EDL) and soleus (Sol) muscles in rats. Adult Wistar rats were assigned to ischemia alone (isch), ischemia-exercised (exe), ischemia-vitamin C (vit C), and ischemia-exercise-vitamin C (vit C + exe) groups. Ischemia was achieved via unilateral ligation of the right common iliac artery. Contralateral muscles within the same animal served as controls. Exercise protocol consisted of 50-min intermittent level running performed every other day for 5 days. Vitamin C (100 mg/kg body wt) was administered intraperitoneally on a daily basis throughout the 14 days of the experiment. With regard to the EDL muscle, ischemia alone reduced muscle strength, which was not recovered after vitamin C administration. Exercise alone following ischemia induced the most severe structural damage and cross-sectional area decrease in the muscle, yet the reduction in tetanic tension was not significant. Exercise in conjunction with vitamin C administration preserved ischemia-induced EDL muscle tetanic tension. In the Sol muscle, a significant reduction in single twitch tension after vitamin C administration was found, whereas the tetanic force of the ischemic Sol was not significantly decreased compared with the contralateral muscles in any group. Ischemic Sol muscle cross-sectional area was reduced in all but the exe groups. In Sol, muscle strength was reduced in the vit C group, and mean cross-sectional area of ischemic Sol muscles was reduced in all groups except the exe group. These results illustrate that mild exercise, combined with a low dose of vitamin C supplementation, may have beneficial effects on ischemic EDL muscle with a smaller effect on the Sol muscle.
Loizidis
T
T
Laboratory of Physiology, Faculty of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
Sioga
A
A
Economou
L
L
Frosinis
A
A
Kyparos
A
A
Zotou
A
A
Albani
M
M
D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D002908:Chronic Disease; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D005260:Female; D007511:Ischemia / Q000473:pathology / Q000503:physiopathology* / Q000517:prevention & control; D008297:Male; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000187:drug effects / Q000473:pathology / Q000648:ultrastructure; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar
D000975:Antioxidants; D001205:Ascorbic Acid