Assessment of cellular profile and lung function with repeated bronchoalveolar lavage in individual mice

In this study, we sought to develop procedures that would enable repeated bronchoalveolar lavage (BAL) in individual mice on multiple occasions. To achieve this objective, we first developed the procedures that would allow individual mice to survive a whole lung lavage, and then tested whether, on subsequent days, there was an effect of this initial BAL on the cell profile, lung permeability, and baseline respiratory function. Our results demonstrate that the repeated lavage procedure can be readily carried out in individual mice of different strains on multiple occasions. The lavage procedure itself results in immediate increases in respiratory system resistance and concomitant decreases in compliance, but these parameters return to prelavage values by the 2nd or 3rd day postlavage. Lavage also induces variable increases in inflammatory cells depending on the strain used. However, in all three strains examined here (A/J, BALB/c, and C3H/HeJ), inflammatory cell numbers returned to baseline values within 3 days after an initial lavage procedure. The ability to perform repeated BAL in individual mice should prove to be an extremely useful tool in a variety of functional genomic studies in the lung.