ASSESSMENT OF BLEOMYCIN LUNG TOXICITY USING ANGIOTENSIN-CONVERTING ENZYME IN PULMONARY LAVAGE

  • 1 January 1980
    • journal article
    • research article
    • Vol. 40  (10) , 3621-3626
Abstract
Activity of the dipeptidyl hydrolase angiotensin-converting enzyme has been observed to be altered by treatment with bleomycin. An animal [rat] model of bleomycin lung toxicity to study the effects on angiotensin-converting enzyme activity in various lung fractions. Serum activity of angiotensin-converting enzyme increased only 23% after a single intratracheal instillation of bleomycin. Lung tissue angiotensin-converting enzyme activity fell to 40% of control level (P < 0.05) and returned toward and eventually exceeded control values during the ensuing 6 wk. Angiotensin-converting enzyme activity in alveolar lavage fluid from bleomycin-treated rats was elevated 30-fold above the barely detectable levels found in control animals. Angiotensin-converting enzyme activity in lavage fluid was soluble and was not associated with the alveolar cell pellet. Maximum elevation of lavage angiotensin-converting enzyme activity occurred 3 days following bleomycin instillation. Significant transudation of serum into alveolar lavage fluid occurred in bleomycin-treated rats. This phenomenon would not explain the high levels of angiotensin-converting enzyme activity found in lavage fluid. Elevated lavage angiotensin-converting enzyme levels were detected after doses of bleomycin too low to cause significant sequelae of pulmonary fibrosis. Lavage angiotensin-converting enzyme is a sensitive monitor of tissue response to bleomycin.