Fig. 2.

Effects of lysophosphatidylcholine (LPC) on intracellular calcium concentration ([Ca²⁺]_i) in human umbilical vein endothelial cells (HUVECs). (A) LPC increased [Ca²⁺]_i dose-dependently in a 1.8 mmol/L Ca²⁺ bathed-external solution. (B) The effects of LPC on [Ca²⁺]_i depend on the external Ca²⁺ in HUVECs. LPC induced only an initial transient peak of [Ca²⁺]_i in the absence of external Ca²⁺ and did not elicit the increase of [Ca²⁺]_i under treatment with endoplasmic reticulum blockers: 50 μmol/L dantrolene and 10 μmol/L U73122. The sustained [Ca²⁺]_i increase represents Ca²⁺ influx from the extracellular solution. (C) Effects of chlorogenic acid (CGA) on LPC-induced [Ca²⁺]_i in HUVECs. The CGA blocked the LPC-induced sustained [Ca²⁺]_i increase. (D) No effect of CGA without LPC in HUVECs. CGA (300 μmol/L and 1,000 μmol/L) was treated without Ca²⁺ and with 1.8 mM Ca²⁺ in HUVECs. Data are the mean values of three independent experiments.