Exercise capacity in hamsters with elastase-induced emphysema compared to normal controls.

The purpose of this study was to determine whether hamsters with elastase-induced emphysema (EMP) would demonstrate a reduction in exercise capacity compared to control (CON) hamsters and whether changes in activity levels, muscle function and structure could explain any changes in exercise capacity. Peak oxygen consumption and daily activity levels were measured on two occasions. Inspiratory capacity under deep anesthesia, in vitro measurements of muscle force and fatigability for the diaphragm (DIA) and extensor digitorum longus (EDL) and fiber proportions, muscle cross-sectional area and fiber specific SDH activity from the DIA, EDL and vastus lateralis (VLA) were obtained. Inspiratory capacity was 60% higher in the EMP compared to CON hamsters (p=0.0004). Activity levels and exercise capacity were not significantly different between EMP and CON hamsters. Muscle strength and fatigability, fiber proportions, muscle cross-sectional area and fiber specific SDH activity were similar between EMP and CON hamsters. In conclusion, in hamsters, elastase-induced emphysema did not reduce maximal exercise capacity.