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SODIUM‐DEPENDENT, ETHYLISOPROPYLAMILORIDE‐SENSITIVE MECHANISMS REGULATE INTRACELLULAR pH IN HUMAN VASCULAR SMOOTH MUSCLE
Author(s) -
Bobik Alex,
Neylon Craig B.,
Little Peter J.,
Jr Edward J. Cragoe,
Weissberg Peter L.
Publication year - 1990
Publication title -
clinical and experimental pharmacology and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 103
eISSN - 1440-1681
pISSN - 0305-1870
DOI - 10.1111/j.1440-1681.1990.tb01324.x
Subject(s) - vascular smooth muscle , intracellular , intracellular ph , chemistry , microbiology and biotechnology , sodium , biophysics , smooth muscle , biochemistry , endocrinology , biology , organic chemistry
SUMMARY 1. The pH‐sensitive dye 2,7‐biscarboxy‐ethyl‐5(6)‐carboxyfluorescein (BCECF) was used to examine the contribution of Na+‐H+ exchange and bicarbonate‐dependent processes to intracellular pH (pH i ) regulation in cultured human vascular smooth muscle. 2. The recovery of pH i following an NH 4 Cl‐induced acidosis was Na+‐dependent and could be inhibited by ethylisopropylamiloride (200 μmol/L). Recovery was unaffected by the anion exchange inhibitor 4‐acetamido‐4′‐isothio‐cyano‐stilbene‐2,2′‐disulfonic acid (200 μmol/L). 3. Recovery from intracellular acidosis was more rapid when bicarbonate ions were present in the extracellular medium. 4. The results suggest that Na+‐H+ exchange as well as an Na+‐dependent bicarbonate process, which can be inhibited by ethylisopropylamiloride, can influence the ability of smooth muscle to recover from intracellular acidosis.