缝隙连接及其与血管舒缩功能调节的关系

Relation between gap junction and the modulation of vasomotor function

缝隙连接是存在于相邻细胞间的膜通道结构,它的基本组成单位是连接蛋白。缝隙连接不仅在细胞间起机械连接作用,它还可以通过电偶联和化学偶联两种方式介导细胞间电和化学信号的传递,当机体受到外部或内部刺激后,缝隙连接可以通过改变连接蛋白的表达使机体适应这种变化。连接蛋白的磷酸化状态与缝隙连接形成密切相关,MAPK,PKC,c-Src,PKA和CK1等激酶可以磷酸化连接蛋白,并调节缝隙连接的功能。血管内皮细胞(VEC)与平滑肌细胞(VSMC)间的缝隙连接被称为肌内皮缝隙连接(MEGJ),它可以穿过内弹力层使VEC和VSMC进行直接的电和化学信号交流,VEC通过MEGJ实现其调节血管张力的功能。缝隙连接交流参与了失血性休克后血管低反应性的调节。

Gap junction （GJ） is thought as the cell membrane channel which comprises of connexins and allows electronic signal, ions, small metabolites （ 〈 1 kD）, and second messengers to translocate from cell to cell. GJ not only takes an important role in mechanical connection between cells, but also mediates the electronic and chemical signal transmition between cells. GJ can change the expression of connexins to adapt the outside stimula. The phosphorylation of connexins is intimately related to the con- formation of GJ. Kinases （ MAPK, PKC, c-Src, PKA and CK1 ） can phosphorylate the connexins and regulate the GJ＇ s function. GJ between the vascular endothelial cell and vascular smooth muscle cell is named as myo-endothelial gap junction （ MEGJ）, which allows direct and bidirectional electronic and chemical communication among cells and plays central roles in the regulation of vascualr tone and hyporeactivity after hemorrhagic shock.