首页 | 本学科首页   官方微博 | 高级检索  
   检索      


Effect of Ca2+ on Structure and Fluidity of Microvillus Membranes of Human Placenta
Abstract:This investigation shows the effect of a Ca2+ addition on the structural and physicochemical properties of microvillus plasma membranes obtained from human placenta. Ca2+ addition induces an increase in microviscosity, as shown by the increase of order parameter and rotational correlation time of 5-and 16-doxylsterate derivatives and by the increase of fluorescence polarization of diphenylhexatriene. All the effects were obtained in a wide temperature range. The morphometric analysis of the ultrastructural images shows that the vesicle profiles of syncytiotrophoblast membranes decrease both area and form factor (FF) in the presence of Ca2+ with respect to the controls. The freeze-fracture results also show that Ca2+ induces an enhanced tendency to IMP clusterization. The Ca2+-induced changes were observed in both E and P faces. Our results underline the important role of Ca2+ in the cell membrane structure per se and in modulating interactions between cytoplasmic and extracellular microenvironments. The results of morphometric analysis of the ultrastructural images agree with biochemical data showing an increased stability induced by calcium on plasma membranes.
Keywords:Ca2+ membrane interaction  membrane fluidity  transmission electron microscopy  freeze-fracture  syncytiotrophoblast plasma membrane (men)
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号