Protein kinase C-mediated intracellular alkalinization in rat and rabbit aortic smooth muscle cells.
The influence of protein kinase C (C-kinase) activation on intracellular pH (pHi) of cultured rat (RASM) and rabbit (RBASM) aortic smooth muscle cells was studied by employing a pH-sensitive fluorescent-dye 2,7-biscarboxyethyl-5,6-carboxyfluorescein (BCECF). The known C-kinase activators 12-O-tetradecanoylphorbol-13-acetate (TPA), phorbol 12,13-dibutyrate (PDBu) and mezerine as well as the agonist angiotensin II each caused an intracellular alkalinization of approximately 0.1-0.15 pH units in RASM and RBASM cells grown in serum-free conditions. TPA-induced alkalinization was sensitive to the Na+/H+ exchange blockers amiloride and 5-N-ethylisopropyl-amiloride (EIPA). These results suggest that protein kinase C activation leads to intracellular alkalinization in vascular smooth muscle cells and the increase in pHi might play an important role in receptor-coupled arterial contraction.
Danthuluri
N R
NR
Section of Pharmacology, College of Pharmacy and Allied Health Professions, Northeastern University, Boston, MA 02115.
Berk
B C
BC
Brock
T A
TA
Cragoe
E J
EJ
Deth
R C
RC
D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000166:cytology; D002478:Cells, Cultured; D005456:Fluorescent Dyes; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism*; D011817:Rabbits; D051381:Rats
D005456:Fluorescent Dyes; D000584:Amiloride; D011493:Protein Kinase C