Effects of hawthorn leaf polymeric procyanidins on calcium mobilization in human umbilical vein endothelial cells / 中国病理生理杂志

ABSTRACT

AIM:To observe the effects of hawthorn leaf polymeric procyanidins ( PPC) on calcium mobiliza-tion of vascular endothelial cells , and to study the underlying mechanism .METHODS: Free calcium in cultured human umbilical vein endothelial cells (HUVECs) was labeled with Fura-2.HUVECs were treated with ATP, a positive control drug, and PPC at concentrations of 12.5, 25 and 50 mg/L..The intracellular calcium concentrations were measured with a living cell microscope for 30 min.RESULTS:PPC concentration-dependently increased the intracellular calcium concen-tration of HUVECs .The intracellular calcium concentrations in 25 and 50 mg/L PPC groups were significantly higher than that in normal group (P<0.01).The dynamic manner of calcium concentration elevations elicited by PPC was a slow in -crease which happened after a latency time of several minutes , lasted for several minutes , and reached a plateau finally . This manner was quite different from that elicited by ATP , a typical SOC operator , hinting different mechanisms between them .Inhibiting the intracellular calcium release did not influence the effects of PPC;however , deleting extracellular calci-um, inhibiting the reverse mode of Na +-Ca2+exchange, or deleting extracellular sodium , restrained or even abolished the effects of PPC.CONCLUSION:PPC elicits calcium mobilization in vascular endothelial cells , which may be one of the mechanisms of the vascular modulatory activity of hawthorn procyanidins .This effect may be achieved through inducing the influx of sodium and then activating the reverse mode of Na +-Ca2+exchange.