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标题：Changes in membrane potential of human granulocytes antecede the metabolic responses to surface stimulation
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作者：H. M. Korchak ; Gerald Weissmann
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1978
卷号：75
期号：8
页码：3818-3822
DOI：10.1073/pnas.75.8.3818
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Human granulocytes (polymorphonuclear leukocytes) exposed to surface stimuli [e.g., immune complexes, concanavalin A (Con A)] generate O2{middle dot}-, undergo a respiratory burst, and secrete lysosomal enzymes. To study the earliest reaction of ligands with surface receptors of granulocytes, purified cells were exposed to bovine serum albumin-anti-albumin complexes (Fc receptors) or Con A (glycoprotein receptors). The membrane potential ({Delta}{Psi}) was measured by distribution of the lipophilic cation [3H]triphenylmethyl phosphonium ion. The Nernst equation yielded a resting {Delta}{Psi} of -26.7 mV. Beginning within 10 sec after exposure to the antigen-antibody complex or to Con A, the cells responded with a rapid hyperpolarization [->] depolarization [->] slow hyperpolarization. Even when phagocytosis was inhibited by cytochalasin B, the triphasic response was obtained: evidence for surface interaction. The hyperpolarization response anteceded O2{middle dot}- generation (continuous recording) by at least 20-30 sec. O2{middle dot}- generation in response to immune complexes was stimulated by Ca2+ whereas {Delta}{Psi} remained unchanged; lack of Ca2+ in the medium did not inhibit the {Delta}{Psi} response. Dissociation of membrane hyperpolarization from subsequent metabolic responses (O2{middle dot}- generation) was also found in the presence of steroids (hydrocortisone, methylprednisolone), which inhibited O2{middle dot}- generation but did not inhibit the {Delta}{Psi} response to antigen-antibody complex. Because O2{middle dot}- generation could be stimulated (Ca2+) or depressed (steroids) without affecting {Delta}{Psi
关键词：concanavalin A ; immune complexes ; triphenylmethyl phosphonium ion ; O₂·^- generation