RESUMEN
A model for creating and repairing diaphragmatic hernia in fetal lambs has been developed. Morphometric studies of the type II alveolar cells were carried out in three groups of term lambs. The upper lobes only were sampled. Morphometric analysis of the 30 type II cells from each lobe showed that while there were no differences between the left upper lobe (LUL) and right upper lobe (RUL) cells in normal lambs, there were significant differences between sides in the experimental groups. In lambs with a nonrepaired diaphragmatic hernia (DH) the type II cells were significantly smaller in the LUL compared with the RUL. In lambs with a repaired DH, the LUL type II cells were significantly larger than those in the RUL. There were some trends when the groups were compared, but in general they did not reach statistical significance. These findings suggest that local factors profoundly influence the development of these cells.