Aim To explore the role of endothelial gap junctions in intercellular communication and vascular endothelial wound repair.Methods Rat aortic endothelial cells(RAEC)were cultured by explanted rat aortic wall tissue.Cell immunofluorescence staining was applied to detect the expressions of connexin(Cx)37,Cx40 and Cx47 in RAEC.Fluorescence redistribution after photobleaching(FRAP)was used to measure the communications between cells via gap junctions.The monolayer of cultured RAEC was scraped by a mechanical method and the endothelial wound healing rate was quantified by an analysis of the photographs taken every 24 h after endothelial cell layers were wounded.Meanwhile,18α-glycyrrhetinic acid(18α-GA),a specific blocker of gap junction,was administered to observe its effect on endothelial wound repair.Results Cx37,Cx40 and Cx47 were all expressed in RAEC.Fluorescent dye could only be transferred between conjugated cells,and mean fluorescence recovery rate in isolated cells were significantly lower compared with that in conjugated cells(5.70%±0.63% vs 82.26%±1.68%,p<0.01).Compared with control group,mean fluorescence recovery rate in 18α-GA group were significant lower(53.58%±1.73% vs 82.26%±1.68%,p<0.05).Therefore,18α-GA could inhibit dye transfer between conjugated cells.The scrape width of endothelium were similar in two groups at the time of wound.However,at 24 h after endothelial wound,the scrape width in 18α-GA group were significantly bigger than those in control group(237.38±20.40 μm vs 126.29±21.40 μm,p<0.05).The complete recover time of the wound in 18α-GA group were significantly more than those in control group(4.2±0.2 d vs 2.6±0.3 d,p<0.05).Conclusions There are intercellular communications via gap junctions among conjugated RAEC and 18α-GA could inhibit the intercellular communication via gap junctions,slow down endothelial wound repair speed and prolong the complete recover time of endothelial wound.Hence,endothelial gap junctions might play a vital role in the process of endothelial wound repair.