Figure 7.

Increased collagen deposition after prenatal nicotine exposure is dependent on α7 nAChR signaling. Lungs from both wild-type and α7 nAChR–deficient adult mice (α7 nAChR^−/−) were obtained after prenatal nicotine exposure for RNA isolation. Using quantitative real-time PCR, collagen 1 mRNA levels were measured and results represented are normalized to 18S as the housekeeping gene. Unlike wild-type mice, mice deficient in α7 nAChR did not have up-regulation of collagen 1 mRNA levels after prenatal nicotine exposure (A). Collagen deposition, as identified by Masson trichrome stain, was not different in α7 nAChR^−/− adult mice after prenatal nicotine exposure (B–C). Scale bar, 100 μm. Error bars denote SEM. *P < 0.05 compared with nicotine.