MIGRATION OF GUINEA-PIG AIRWAY EPITHELIAL-CELLS IN RESPONSE TO BOMBESIN ANALOGS

Bombesin-like peptides within neuroepithelial cells elicit proliferati on of normal and malignant airway epithelial cells. It is not clear th at these peptides also elicit epithelial cell migration, a necessary c omponent of airway repair after injury. We studied the effects of the bombesin analogues, gastrin releasing peptide (GRP) and neuromedin B ( NMB), on guinea pig tracheal epithelial cell (GPTEC) migration. Primar y GPTEC were allowed to migrate through 8-mu m-pore gelatin-coated fil ters for 6 h in a chemotaxis chamber, after which the number of migrat ed cells per 10 high power fields (10 hpf) were counted. Both neuropep tides elicited migration of GPTEC: 24.8 +/- 4.5 cells for 10(-11) M NM B (P < 0.001 versus control, n = 4) and 16.8 +/- 1.2 cells for 10(-12) M GRP (P < 0.001 versus control, n = 8). Migration was attenuated sub stantially by a bombesin receptor antagonist. To investigate further t he relationship of migration through a filter to the repair of a damag ed epithelium, we studied the repair of epithelial cells by video micr oscopy. A 0.3- to 0.5-mu m(2) wound was created in a confluent monolay er of GPTEC, and wound closure was followed over 24 h. There was no si gnificant acceleration in the rate of repair of GRP- or NMB-stimulated monolayers compared to control. These data demonstrate that GRP and N MB elicit migration of airway epithelial cells but may not play a sign ificant role in the early repair of the airway epithelium in culture.