Experimental study of WGA binding on the endothelial cell surface in cerebral ischemia

The relationship between the saccharide chain on the endothelial cell surface and the permeability of intracerebral blood vessels has been studied. In the present study, wheat germ agglutinin (WGA) was perfused into capillaries in the area postrema of the normal Mongolian gerbil, where the blood brain barrier (BBB) is known to lack, and into intracerebral blood vessels, the BBB of which had been destroyed by experimentally induced brain ischemia. The light microscopic features of the sections from WGA-perfused brain tissues of the normal gerbil revealed that most of the blood vessels, including capillaries in the brain parenchyma, showed positive findings (the reaction induced a very distinct staining of the vascular wall) from which the course and structure of the fine vessels could be determined. The reaction to WGA on the diaphragma fenestra (DF) in capillaries in the area postrema was relatively weak, and DF without the reaction were occasionally revealed by electron microscopy. The gerbil, in which cerebral ischemia had been induced, also showed partial defect of the reaction with WGA on the luminal side of the endothelial cells. The results of the present experiment suggest some degree of correlation between the saccharide chains, including the specific monosaccharide of WGA, on the endothelial cell surface and permeability. It was considered that lectin can be used as an index for morphological observations, suggesting an alteration in function of the endothelial cell membrane. In addition, the perfusion method in this experiment suggested the possibility of distinguishing pinocytotic vesicles from pits of cell membranes.