title: The action of low density lipoprotein on vascular smooth muscle cells involves increase in intracellular pH.
abstract: The effect of low density lipoprotein (LDL) on the intracellular pH (pHi) of vascular smooth muscle cells (VSMC) was investigated using a fluorescent pH indicator, 2',7'-bis(carboxyethyl)carboxyfluorescein (BCECF). LDL and apoprotein B (apo-B), a binding protein for the LDL receptor, caused transient acidification followed by Na(+)-dependent and amiloride-sensitive alkalization of the cells due to stimulation of Na+/H+ exchanger. NH4Cl also caused intracellular alkalization, but independently of extracellular Na+. LDL, apo-B and NH4Cl all stimulated thymidine incorporation. These results indicate that the binding of LDL to its receptor stimulates Na+/H+ exchanger, resulting in alkalization of VSMC and suggest that this may function as a massage in stimulation of DNA synthesis evoked by LDL.
authors.affiliation: Department of Geriatric Medicine, Osaka University Medical School, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Koh
authors.forename: S
authors.initials: S
authors.lastname: Morimoto
authors.forename: T
authors.initials: T
authors.lastname: Nabata
authors.forename: Y
authors.initials: Y
authors.lastname: Miyashita
authors.forename: S
authors.initials: S
authors.lastname: Kitano
authors.forename: R
authors.initials: R
authors.lastname: Morita
authors.forename: T
authors.initials: T
authors.lastname: Ogihara
mesh_terms: D000584:Amiloride / Q000494:pharmacology; D000643:Ammonium Chloride / Q000494:pharmacology; D001055:Apolipoproteins B / Q000494:pharmacology; D002478:Cells, Cultured; D006863:Hydrogen-Ion Concentration; D008077:Lipoproteins, LDL / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism*; D012964:Sodium / Q000494:pharmacology; D013936:Thymidine / Q000378:metabolism
chemical_list: D001055:Apolipoproteins B; D008077:Lipoproteins, LDL; D000643:Ammonium Chloride; D000584:Amiloride; D012964:Sodium; D013936:Thymidine