Measurement of the parameters MLI and MAA revealed that rAFMSCs could alleviate lung injury in rats with emphysema after being transplanted for 20 and 40 days. Group I, control. Group II, emphysema. Group III, emphysema + rAFMSC transplantation for 20 days. Group IV, emphysema + rAFMSC transplantation for 40 days. Values are presented as means ± SEM (n = 10). *P < 0.01 versus group I, **P < 0.01 versus group II, #P < 0.01 versus group III. MLI =μmean linear intercept; MAA =μmean alveolar airspace.