Transmembrane potential changes during phagocytosis in rat alveolar macrophages.
Miles-PR; Bowman-L; Castranova-V
J Cell Physiol 1981 Jan; 106(1):109-117
Phagocytosis induced changes in transmembrane potential were studied in rat alveolar macrophages. Alveolar macrophages harvested from male Long-Evans-rats were incubated with 4 milligrams (mg) zymosan (9010724) or 50 micrograms (microg) phorbol-12-myristate-13-acetate (62384) (PMA) and the effects on superoxide-anion (O2-) release and transmembrane potential were monitored for up to 100 minutes. Alveolar macrophages were incubated with 0 to 4mg zymosan or 0 to 16microg/milliliter PMA to assess the concentration effects on O2- release and transmembrane potential. Alveolar macrophages were preincubated with 0, 5, or 150 millimolar (mM) potassium-chloride to depolarize them. They were then incubated with 0 or 4mg zymosan. The effects on O2- release and transmembrane potential were examined. Phagocytosis of either zymosan or PMA by rat alveolar macrophages resulted in membrane depolarization and release of O2-. Membrane depolarization preceded the release of O2-. The magnitude of depolarization and O2- release increased with increasing PMA or zymosan concentration. Preincubation with potassium-ion (K+) induced release of O2-. The magnitude of depolarization induced by 150mM K+ was only about 20 percent of that induced by zymosan. The amount of O2- released was reduced by pretreatment with K+. The authors conclude that release of O2- from rat alveolar macrophages after ingesting foreign particles is associated with depolarization of the cell membrane.
NIOSH-Author; Phagocytic-activity; In-vitro-studies; Alveolar-cells; Physiological-chemistry; Bioelectric-effects; Particulates; Oxidative-processes; Dose-response
Journal of Cellular Physiology