- 作者: Tung-Yi Huang, Hsiun-Ing Chen, Chin-Yen Liu, Chauying J. Jen
- 作者服務機構: Department of Physiology and Institute of Basic Medical Sciences, College of Mediclne, Nationa Cheng Kung University Tainan, Taiwan, ROC
- 中文摘要: --
- 英文摘要: EC [Ca ] level and the accompanying vasoconstriction.Pretreatment with 20 M LPC reduced the basal EC[Ca ] level and abolished the calcium-free solution-induced EC [Ca ] reduction and vasoconstriction. Weconclude that LPC impairs endothelium-dependent va-sorelaxation mainly by reducing the basal EC [Ca ] leveland suppressing agonist-evoked EC [Ca ] signaling.The detailed mechanism of how lysophosphatidylcho-line (LPC) suppresses endothelium-dependent vasodila-tation is unclear at present. We investigated the effects ofLPC on endothelial intracellular calcium (EC [Ca ] ) sig-naling and vascular tone simultaneously using a newtechnique we developed. Fura-2-labeled rat aortic speci-mens were mounted in a tissue flow chamber and pre-contracted with phenylephrine (5 x 10 M). Under eith-er basal or agonist-stimulated conditions, the EC [Ca ] level was calculated from fura 2 fluorescence ratioimages, and the vascular tone was estimated by measur-ing the relative displacement of the fluorescence images.Although both acetylcholine (ACh)-induced EC [Ca ] elevation and the concomitant vasorelaxation were par-tially suppressed in specimens pretreated with LPC(20 M), the quantitative relationship between EC [Ca ]elevation and the corresponding vasorelaxation wasunaffected. A high concentration of LPC (40 M) com-pletely eliminated ACh-evoked [Ca ] elevation and va-sodilatation. It has been reported that exposing vasculartissue to a calcium-free buffer causes a reduction in the
- 中文關鍵字: --
- 英文關鍵字: Calcium, Endothelium, Lysophosphatidylcholine Vasodilatation