Abstract

BACKGROUND
This study was to clarify the influence of collapse and re-ventilation of lung on the development of pulmonary edema in rabbit. METHODS: Animals were randomly assigned to one of three groups: Sham group receiving two lung ventilation (n=14), Collapse group receiving collapse of right lung (n=14), Reventilation group receiving collapse of right lung for 3 hours followed by reventilation of collapsed right lung for 3 hours (n=14). The lung of rabbits were ventilated with 50% oxygen through the tracheostomy. Right main bronchus was secured by thoracotomy in all animal. Collapse and reventilation were performed using by bulldog forcep. Mean arterial pressure, heart rate, arterial oxygen tension (PaO2), peripheral blood leukocyte and platelet counts were recorded at 0, 1, 2, 3, 4, 5 and 6 hour after the start of experiment. The wet to dry (W/D) weight ratio of lung, lung injury score and leukocyte counts, percentage of polymorphonuclear leukocyte (PMNL), concentration of albumin, and interleukin-8 (IL-8) in bronchoalveolar lavage fluid (BALF) were measured 6 hour after the start of experiment in both lung. RESULTS: W/D weight ratio of lung, lung injury score and leukocyte counts, percentage of PMNL, concentration of albumin and IL-8 in BALF were significantly increased in both lung of reventilation group. And the degree of increases is more significant in right than left lung. CONCLUSIONS: These findings suggest that reventilation of collapsed lung causes the bilateral pulmonary edema in rabbit mainly by activating neutrophil and IL-8 responses, which may play a central role in non cardiogenic pulmonary edema.

• Keywords: Interlukin-8;Neutrophil;Pulmonary edema;Re-ventilation;