Figure 2.

Branching morphogenesis in a rat lung explant system. At 13 days of gestation, lungs were removed from the fetuses and cultured in a semidry system. The upper row of pictures are representative for lungs at 13 days of gestation at culture day 0 just after isolation of the lungs from the fetus. The bottom row of pictures represents lungs after a culture period of 4 days. One group was treated with Nitrofen in vivo by administration of the Nitrofen to the mother at 9 days of gestation (D and H) Another group was treated with Nitrofen in vitro as described before (G). Branching morphogenesis was compared to groups cultured in medium alone (E), and groups cultured in medium plus vehicle DMSO (F). In all Nitrofen-exposed explants a statistically significant (P < 0.05) reduced number of branches was observed after 4 days of culture (G and H), whereas no effects of exposure to DMSO were observed (F; see also Figure 3 ▶ and Table 2 ▶ ). In addition, the size of the explants exposed to Nitrofen was clearly reduced (G and H). The effects of Nitrofen exposure in vitro were more severe than the effects after Nitrofen exposure in vivo. All pictures are representative of a series of experiments. Scale bar represents magnification level.