The effect of exercise on skeletal muscle morphology in an experimental model of acute congestive heart failure

grantor: University of TorontoSkeletal muscle fiber-capillary morphology was investigated in four groups of 12-14 weeks old rats: myocardial infarct exercise (IE; n = 6), myocardial infarct sedentary (IS; n = 5), sham exercise (SE; n = 5), and sham sedentary (SS; n = 5). Myocardial infarct (MI) was induced by ligation of the left anterior descending (LAD) coronary artery. All MI rats were allowed a 35 day healing time before exercising. Exercise training for 6 weeks involved swimming at 5 min/day and increasing 5min/day until the rats were swimming continuously for 40 minutes 5 days/week. The plantaris muscle was sectioned and stained for assessment of muscle-capillary morphometrics for both type I and II fibers. Multiple pairwise comparisons was done by two way ANOVA. All statistical analysis where p < 0.05 are considered to be significant. Changes in muscle fiber size were assessed by fiber area (FA) and perimeter (P). Capillary indices were measured by capillary contacts (CC) and individual capillary-to-fiber ratio (C:Fi) by pairwise comparisons among the four groups. (Abstract shortened by UMI.)M.Sc