Journal of Applied Physiology, Vol 68, Issue 3 967-972, Copyright © 1990 by American Physiological Society
Effect of exercise on redistribution and clearance of inhaled particles from hamster lungs
T. D. Sweeney, A. F. Tryka and J. D. Brain
Department of Environmental Science and Physiology, Harvard School of Public Health, Boston, Massachusetts 02115.
Does exercise alter the redistribution and clearance of particles from the
lungs? Sedentary hamsters and hamsters that were exercise trained by
voluntary wheel running for the previous 5 wk were exposed to a
198Au-labeled aerosol for 25 min. Six trained and 6 sedentary animals were
killed within 5 min after the exposure (day 0); the same number were killed
5 days later. The trained hamsters ran ad libitum during those 5 days. The
lungs of all animals were excised, dried at total lung capacity, sliced
into 1-mm-thick sections, and dissected into pieces that were counted for
radioactivity and weighed. On day 0, trained hamsters had 80% more
particles per milligram of lung than sedentary hamsters, although both were
exposed under identical conditions of restraint. After five days,
exercising hamsters cleared 38% of the particles present at day 0, whereas
sedentary animals removed only 15%. Significant clearance was observed from
the middle lung regions of sedentary hamsters and from all lung regions in
exercising hamsters. We conclude that exercise can enhance the
redistribution and clearance of particles from the lungs; the mechanisms
responsible are as yet unclear.
