Ultrastructural changes in the tight intercellular junctions of the endoneurial blood vessels following sural nerve crush injury in rats

The objective of this study was to investigate the ultrastructural changes in the tight intercellular junctions of the endoneurial blood vessels after nerve injury. Twenty-one adult male Sprague-Dawley rats were used in the study (3 animals as a control group and left sural nerves of 18 animals were subjected to the crush). At intervals of 1, 2, 3, 4, 5 and 6 weeks after crush, 3 rats /sitting were killed and the fixed crushed nerves were collected. The normal and crushed nerves were prepared for electron microscopic study. The number of the tight intercellular junctions was at a mean of 4± 0.03 per intercellular junction in the crushed nerves compared to 5±0.09 in the normal. The intercellular junctions showed localized distensions at different sites of the intercellular junctions. Disruption of the luminal and adluminal tight junctions created luminal and adluminal cytoplasmic protrusions respectively. Some of the intercellular junctions showed complete separation of the endothelial cells.The absorbed vesicles form large vesicles that open into the intercellular clefts leading to increased pressure that lead to disruption of the intercellular tight junctions in a cascade manner. Key words: Endoneurium, blood vessel, intercellular, junctions, vesicles, disruption.