Prenatal nicotine increases pulmonary α7 nicotinic receptor expression and alters fetal lung development in monkeys
J. Clin. Invest. Harmanjatinder S. Sekhon, et al. 103:637 doi:10.1172/JCI5232 [Go to this article.]

Figure 2
Immunohistochemical localization of nicotinic receptor subtypes in 134-day fetal monkey lung. a and c from control fetus; b and d from nicotine-exposed fetus. (a) Anti-α7 (MAB 319) showing brownish-red staining in fibroblast cell layer in cartilaginous airways and vessel walls. ×100. (b) In nicotine-exposed fetus, greatly enhanced α7 staining is seen in cartilaginous airway and vessel walls. ×100. No immunostaining was seen with nonimmune serum (not shown). (c and d) Higher-power view of smaller cartilaginous airways showing relatively little α7 in airway wall and epithelial cell lining in control lung, but intense staining in airway wall and epithelial cells (arrows) from nicotine exposed lung. ×400. Procedure as described in the research plan: AEC was used as immunoperoxidase substrate, and hematoxylin was used as counterstain. A, airway lumen; V, blood vessel lumen; C, cartilage; AEC, 3-amino-9-ethylcarbazole; MAB, monoclonal antibody.