EFFECT OF PHYSICAL EXERCISE ON ELASTASE-INDUCED EMPHYSEMA IN HAMSTERS

Abstract

The effect of physical exercise on the evolution of elastase-induced emphysema was investigated with morphometric methods in hamsters. The animals were given an intratracheal injection of 0.1 mg of pancreatic elastase and were divided into rest and exercise groups. Exercise was done in motor-driven activity wheels for 4 h/day, 5 days/wk. Controls consisting of animals given a saline injection followed the same schedule. One week after the insult, both elastase-treated groups (rest and exercise) showed significant emphysematous changes, as assessed by an increase of the mean linear intercept and a decrease of the internal surface area of the lungs. By the 5th wk, emphysema had progressed significantly (.apprx. 20%) in both elastase groups. At neither point was there a significant difference between the rest and exercise groups. At 35 days ultrastructural morphometry of the heart revealed a significant decrease in the percentage of mitochondria and an increase in the percentage of contractile material in the left ventricle of both exercise groups (saline and elastase), changes that are indicative of left-heart overload. Similar changes were in the right ventricle of the elastase-rest animals, and were even more evident in the elastase-plus-exercise hamsters. Apparently exercise does not play a major role in the progression of elastase-induced emphysema. Ultrastructural right-ventricular changes are associated with elastase-induced emphysema.