The chloride channel blocker 5‐nitro‐2‐(3‐phenylpropyl‐amino) benzoic acid (NPPB) uncouples mitochondria and increases the proton permeability of the plasma membrane in phagocytic cells

FEBS Letters

Grinstein, Sergio²  Rotstein, Ori D.¹  Lukacs, Gergely L.²  Nanda, Arvind² 

[1] Department of Surgery, Toronto General Hospital, Toronto M5G 2C4, Canada;Division of Cell Biology, Hospital for Sick Children, 555 University Ave., Toronto M5G 1X8, Canada

关键词: Chloride channel;    NPPB;    Uncoupler;    Cytoplasmic pH;    Proton;    Mitochondrion;    NPPB;    5-nitro-2-(3-phenylpropyl-amino)benzoic acid;    CCCP;    carbonylcyanide m-chlorophenylhydrazone;    BCECF;    2′;    7′;    bis(carboxyethyl)-5;    6-carboxyfluorescein;   

DOI  :  10.1016/0014-5793(91)80992-C

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We present evidence that the potent chloride channel blocker NPPB has protonophoric activity in the mitochondria and across the plasma membrane of phagocytic cells. The resting O₂ consumption of murine peritoneal macrophages was stimulated up to 2.5-fold in the presence of NPPB, with a K _0.5 of 15 μM. The stimulatory effect of NPPB also O₂ consumption, like that of the classical protonophore CCCP, was prevented by the mitochondrial respiratory chain inhibitors antimycin A, rotenone or cyanide. NPPB also mediated rheogenic proton transport across the plasma membrane of human neutrophils and macrophages in the direction dictated by the electrochemical proton gradient. As a consequence of its protonophoric activity, NPPB uncoupled mitochondrial ATP synthesis, resulting in partial depletion of cellular ATP. These observations indicate that, at the concentrations frequently used for blockade of anion channels, NPPB acts as an effective protonophore, potentially disturbing cytosolic pH and mitochondrial ATP synthesis.

【 授权许可】

Unknown