Increased potassium concentration inhibits stimulation of vascular smooth muscle proliferation by PDGF-BB and bFGF

The effects of changes in extracellular potassium concentration on the rate of vascular smooth muscle cell proliferation stimulated by cytokines and s erum were analyzed in vitro. To analyze the DNA synthesis response, cells f rom swine coronary artery were grown in DMEM medium containing 3, 4, 5, or 6 mmol/L potassium together with 20 ng/mL platelet-derived growth factor BB (PDGF-BB), 25 ng/mL basic fibroblast growth factor (bFGF), or 5% fetal bov ine serum (FBS), with [methyl H-3] thymidine added, for 24 h. Proliferation responses were analyzed in cells grown in medium with potassium concentrat ions of 3, 4, 5, or 6 mmol/L, together with either 20 ng/mL PDGF-BB, 25 ng/ mL bFGF, or 5% FBS, for 7 days, then harvested and counted. Highly signific ant inverse relationships were observed between potassium concentration and H-3-thymidine incorporation stimulated by each of the three agonists (P <. 01 for each, ANOVA), and between potassium concentration and proliferation (all P <.01, ANOVA). Elevation of potassium concentration within the physio logic range inhibits vascular smooth muscle cell DNA synthesis and prolifer ation. Am J Hypertens 2000;13:1055-1060 (C) 2000 American Journal of Hypert ension, Ltd.