Effects of Serotonin on Intracellular pH and Contraction in Vascular Smooth Muscle

• Published in: Circulation research 1992-12, Vol.71 (6), p.1294-1304
• Main Authors: Kahn, Andrew M, Bishara, Maher, Cragoe, Edward J, Allen, Julius C, Seidel, Charles L, Navran, Stephen S, OʼNeil, Roger G, McCarty, Nael A, Shelat, Harnath
• Format: Article
• Language: English
• Subjects: 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid - analogs & derivatives; 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid - pharmacology; Amiloride - analogs & derivatives; Amiloride - pharmacology; Animals; Bicarbonates - metabolism; Biological and medical sciences; Blood vessels and receptors; Cells, Cultured; Chlorides - metabolism; Dogs; Female; Fundamental and applied biological sciences. Psychology; HEPES - pharmacology; Hydrogen-Ion Concentration; Male; Muscle Contraction - drug effects; Muscle, Smooth, Vascular - cytology; Muscle, Smooth, Vascular - drug effects; Muscle, Smooth, Vascular - metabolism; Serotonin - pharmacology; Sodium - metabolism; Stimulation, Chemical; Vertebrates: cardiovascular system
• ISSN: 0009-7330; 1524-4571
• DOI: 10.1161/01.RES.71.6.1294

Serotonin (5-HT) and other contractile agonists stimulate Na-H exchange in vascular smooth muscle. Since intracellular alkalinization, per se, stimulates contraction, we tested whether 5-HT-induced contraction was associated with an increased pHi. In HCO3-free buffer (pH. 7.4), 5-HT (10 M) increased pHi, as measured by 2ʼ,7ʼ-bis(2-carboxyethyl)-5(6)-carboxyfluorescein fluorescence, from 7.10±0.03 to 7.34±0.03 (p