Figure 4: Photomicrographs of the male albino rats lung of the fourth group showing in (A), the edematous blood vessels (o), alveolar duct (d), alveolar sac (s) in normal areas with thickening in the interalveolar septum (arrow) H&E X400. In (B), lymphocytic infiltration still persist around the bronchioles (ly) Masson trichrome X400. In (C), nearly the whole lung tissue back to normal structure although some blood vessles still congested (arrow). H&E X100. In (D), positive immunostaining for bcl-2 (arrows) X400. In (E), few positive immunostaining for bax (arrow) around the bronchioles (b) X400. In (F), few positive immunostaining for ki67 (arrows) X400.