Effect of perinatal nicotine exposure on markers of differentiation in fibroblasts isolated from the lungs of F2 rats (mixed gender). Compared to the control group, with nicotine administration the expression of fibronectin increased and that of PPARγ decreased, at both the protein (A) and mRNA (B) levels. Values are means ± SE. n = 3 for each group. * P < 0.05, versus control group. GAPDH, glyceraldehyde 3-phosphate dehydrogenase; PPARγ, peroxisome proliferator-activated receptor gamma.