Particle binding, phagocytosis, and plastic substrate adherence characteristics of alveolar macrophages from rats acutely treated with chlorphentermine.

Abstract

The effects of acute treatment with the phospholipidosis-inducing agent chlorphentermine (CP) on alveolar macrophage (AM) function heretofore have not been investigated. We evaluated the effects of acute CP treatment on the functional status of AM by comparing Fc receptor (FcR) and "nonspecific substance receptor"-mediated particle binding and phagocytic activities, as well as the plastic substrate adherence characteristics of AM lavaged from control (CONT-AM) and CP-treated (CP-AM) rats. Acute CP treatment caused an impairment in AM phagocytosis and binding of sheep red blood cells opsonized with immunoglobulin G (IgG). Although CONT-AM and CP-AM avidities for tanned human red blood cells were indistinguishable, phagocytosis of these particles by CP-AM was diminished in a manner similar to that found for FcR-mediated phagocytosis. Analyses of the distributions of test particles in phagocytizing CONT-AM and CP-AM indicated that the phagocytic activity of a subset of CP-AM was compromised by drug treatment. Populations of CP-AM were also found to be less adherent in a plastic substrate adherence assay verified with a poorly adherent AM population. Unlike studies involving chronic CP-treatment, our studies indicate acute CP administration results in an impairment in AM phagocytic activity and a reduction in FcR-mediated particle binding.