Magnesium lithospermate B decreases [Ca2+]1 in endothelial cells by inhibiting K+ currents

Magnesium lithospermate B (MLB) is a hydrophilic active component of Salviae miltiorrhizae Radix Studies have shown that MLB affected intracellular calcium ([Ca2+](1)) but the underlying mechanism was unclear yet The present work was aimed to investigate the underlying mechanism of MLB affecting [Ca2+](1) in endothelial cells (ECs) Isolated mesentery arteries were employed to test the involvement of L-Ca2+ channel [Ca2+](1) was measured in ECs loaded with Fluo 3 Membrane potential and membrane currents were recorded in ECs using patch-clamp techniques Results showed that MLB did not inhibit Ca2+ influx via L-Ca2+ channel in isolated mesenteric arteries However MLB decreased [Ca2+](1) in a concentration-dependent manner in ECs MLB depolarized the membrane potential of ECs and inhibited K+ currents These results demonstrated that MLB decreased [Ca2+](1) by inhibiting K+ currents and depolarizing membrane potential in ECs (C) 2010 Elsevier B V All rights reserved