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USE OF REPEATED BRONCHOALVEOLAR LAVAGE IN RABBITS TO ASSESS POLLUTANT-INDUCED LUNG CHANGES IN AN ANIMAL MODEL OF CARDIOVASCULAR (CV) DISEASE.
Citation:
DYE, J. A., R. SLADE, R. H. JASKOT, J. E. RICHARDS, N. MANZO, GEORGE TAYLOR, AND A. J. LAGIER. USE OF REPEATED BRONCHOALVEOLAR LAVAGE IN RABBITS TO ASSESS POLLUTANT-INDUCED LUNG CHANGES IN AN ANIMAL MODEL OF CARDIOVASCULAR (CV) DISEASE. . Presented at American Thoracic Society International Conference, Toronto, ON, CANADA, May 16 - 21, 2008.
Impact/Purpose:
This abstract is on the optimization of repeated bronchoalveolar lavage in rabbits. This procedure would allow for repeated assessment of the same subject during chronic air pollutant exposure studies. Rabbits were used because of their tendency to become hyperlipidemic and develop vascular changes, thus mimicking corronary artery disease.
Description:
Animal models of coronary heart disease (e.g., hyperlipidemic rabbits) are being used to investigate epidemiologic associations between higher levels of air pollution and adverse CV consequences. Mechanisms by which pollutant-induced lung or systemic inflammation leads to acute CV events need to be defined. Hence, we sought to optimize bronchoalveolar lavage (BAL) as a recoverable procedure in laboratory rabbits, thus allowing lung evaluation during a chronic air pollut¬ant study. In study 1, in a cross-over manner, NZW rabbits (n=6) under¬went repeated BAL. Rabbits were sedated, anesthetized with isoflurane, tran¬sorally intubated, oxy¬genated for 5 min. pre- and post-BAL, and monitored via pulse oximetry and end-tidal cap¬nography. Using sterile saline, rabbits were lavaged with: (a) 5-mL aliquots (LO-VOL) or (b) a single 10 mL/kg (HI-VOL) aliquot. Results were compared to a terminal (TERM; 25 mL/kg) procedure. In study 2, NZW rabbits (n=4) were intratracheally instilled with saline or zinc (8-32 µg/kg). 48h later, they were anesthetized and serially lavaged, first using LO- and then HI-VOL aliquots, followed by euthanasia and TERM-BAL. Results. All rabbits recovered uneventfully from LO- and HI-VOL BAL procedures. Recovery time was largely a function of ease of intubation. No bacterial growth was isolated from BAL fluid and CARBacillus serology was negative. The main disadvantage of LO-VOL BAL was inconsistent sample recovery. Conversely, TERM BAL was most consistent, but excessive dilution resulted in several indices falling below detection limits. Thus, use of a single 8-10 mL/kg instillate appears to allow for adequate animal recovery and detection of pollutant-induced lung injury, inflammation, or antioxidant changes. With appropriate care, repeated recovery BAL is feasible in laboratory rabbits. (Abstract does not reflect USEPA policy).