Immunohistochemistry for iNOS ( A ) and arginase-1 ( B ). C: control groups. E: emphysema groups. Mice were treated with saline (SAL), or bone marrow (BM), adipose (AD) and lung (L)-derived mesenchymal stem cells (MSC). IV: intravenous route. IT: intratracheal route. Values are mean × SD of 5-30 mice in each group. All values were computed in ten random, non-coincident fields per animal. *Vs. C group (p < 0.05). #Vs. E-SAL group (p < 0.05). Note positive cells in brown (arrow).