Open AccessDepolarization and increased conductance precede superoxide release by concanavalin A-stimulated rat alveolar macrophages.
Author(s) -
A. R. Cameron,
June Nelson,
Henry Jay Forman
Publication year - 1983
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.80.12.3726
Subject(s) - superoxide , depolarization , concanavalin a , biophysics , respiratory burst , chemistry , extracellular , membrane potential , pulmonary alveolus , membrane , biochemistry , biology , in vitro , macrophage , enzyme
Rat alveolar macrophages release superoxide into the extracellular medium when stimulated by concanavalin A. This process, the respiratory burst, is characterized by a delay between binding of the stimulus and release of superoxide. It has been proposed that a key event that occurs during this delay period is the alteration of membrane electrical potential. Microelectrode impalement was used to directly measure electrical properties of the plasma membrane. Upon addition of concanavalin A, the membrane potential depolarized 21%, and membrane electrical resistance decreased 16%. Parallel chemical measurement of superoxide release indicated that these changes in electrical properties precede the release of superoxide.