Rabbit lungs immunolabeled with TGF-beta by immunoperoxidase. A decrease in the expression of TGF-beta in the vascular endothelium cells and bronchial epithelium of tolerated animals (D) was observed when compared to immunized ones (B, C). There was no significant difference in immunolabeling for TGF-beta between tolerated (D) and control animals (A). TB = terminal bronchiole; V = vessel; Magnification: 400×. Groups: CT-FA = Freund's adjuvant control; IM = immunized; IM-TOL = immunized and tolerated.