A Theoretical Study of Forming Mechanism of Membrane Patent Channels Across Endothelial Cell

(Chained Vesicular Channel and Infundibular Channel)

Abstract

There are several experimental observations which give evidence for the presence of transendothelial cell channels such as chained vesicular channels and infundibular channels, which are membrane patent channels across the endothelial cells. These channels are considered to be involved in specific transport mechanisms of macromolecules, and also there should be some specific mechanisms which lead to their formation. In this study, generalized governing equations were formulated for the transendothelial cell channels. The shapes of axisymmetric transendothelial chained vesicular channel and infundibular channel were computed based on minimization of bending strain energy of the membrane to investigate their forming conditions and morphological characteristics. Simulated transendothelial channel changes its shape dramatically from chained vesicular channel to infundibular channel depending on lower opening radius. Among the channels, the lowest energy equilibrium shape is chained vesicular channel, while radius of the infundibular channel is about half compared to that of adjacent single vesicle or the chained vesicular channel. Simulated shapes are generally in good agreement with experimentally observed shapes. These results provide insights into forming mechanism of membrane patent channels across the endothelial cells.