Control of cytoplasmic pH by Na+/H+ exchange in rat peritoneal macrophages activated with phorbol ester

FEBS Letters

Grinstein, Sergio¹  Rotstein, Ori D.²  Houston, Kimberly² 

[1] Division of Immunology, Hospital for Sick Children, 555 University Ave, Toronto M5G 1X8, Canada;Department of Surgery, Toronto Western Hospital, University of Toronto Canada

关键词: cytoplasmic pH;    Na+/H+ exchange;    Phorbol ester;    Macrophage;    (Rat);    TPA;    12-O-tetradecanoyl phorbol 13-acetate;    BCECF;    2′;    7′-bis(carboxyethyl)-5;    6-carboxy-fluorescein;    NMG+;    N-methyl-D-glucammonium+;   

DOI  :  10.1016/0014-5793(87)80150-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The mechanisms underlying cytoplasmic pH (pH_i) regulation in elicited rat peritoneal macrophages were investigated by electronic sizing and fluorescence determinations. Acid-loaded cells rapidly regained normal pH_i by means of an amiloride-sensitive Na⁺/H⁺ exchange. When stimulated by 12-O-tetradecanoyl phorbol 13-acetate, macrophages displayed a biphasic pH_i change: a marginal acidification followed by an alkalinization. The latter results from activation of Na⁺/H⁺ exchange, since it is Na⁺-dependent and prevented by amiloride. When the antiport is inhibited, the full magnitude of the initial acidification can be appreciated. This acidification is independent of the nature of the ionic composition of the medium and probably reflects accumulation of protons generated during the metabolic burst. Under physiological conditions, these protons are rapidly extruded by the Na⁺/H⁺ antiport.

【 授权许可】

Unknown