Concentration dependent relaxation of acetylcholine (%). Concentration dependent relaxation of acetylcholine (ACh) on thoracic aorta rings obtained from sedentary control (SC), trained control (TC), sedentary diabetic (SD) and trained diabetic (TD) groups precontracted with PE. Tension is expressed as % relaxation on initial contraction with PE. Values are expressed as mean ±SEM. * Significantly different from sedentary control rats (p<0.05), † significantly different from trained control rats.