We studied lung clearance of aerosolized technetium-labeled diethylenetriamine pentaacetic acid (99mTcDTPA), plasma concentrations of 6-keto-PGFlα and thromboxane B2 and pulmonary edema as indices of lung injury in rabbits exposed to cigarette smoke (CSE). Forty-six rabbits were randomly assigned to 4 groups: control sham smoke exposure (SS, N = 9), sham smoke exposure ibuprofen-pretreated (SS-I, N - 10), CSE (N = 9), sham smoke exposure ibuprofen-pretreated (SS-I, N - 10), CSE (N - 9), and CSE ibuprofen-pretreated (CSE-I, N - 19). Ibuprofen (cyclooxygenase eicosanoid inhibitor) was administered as a single daily intramuscular injection (25 mg/kg)for 7 days before the experiment. Cigarette or sham smoke was delivered by syringe in a series of 5, 10, 20, and 30 tidal volume breaths with a 15-min counting period between each subset of breaths to determine 99mTcDTPA biological half-life (T1/2). In the ibuprofen pretreated group, CSE caused significant decreases in 99mTcDTPA T1/2 and dynamic lung compliance. Furthermore, these changes in lung function were accompanied by severe injury to type I alveolar cell epithelium, pulmonary edema, and frequently death of the rabbits. These findings suggest that inhibition of the cyclooxygenase pathway before CSE exacerbates lung injury in rabbits.
ASJC Scopus subject areas
- Molecular Biology
- Pulmonary and Respiratory Medicine
- Clinical Biochemistry