[Disturbance of inhibitory capacity of endothelial cell for platelet adhesion or aggregation following experimental subarachnoid hemorrhage].

Time sequential changes of the endothelial cells of feline basilar arteries after experimental subarachnoid hemorrhage (SAH) were studied morphologically and functionally under the scanning electron microscope (SEM). Experimental SAH was induced by the two-hemorrhage method, and the basilar artery was removed at 1 hour, or 2, 4, 7, or 14 days respectively after the 1st cisternal blood injection. At each stage, morphological changes of the luminal surface and endothelial cells of the basilar artery were observed by SEM. In another group, adenosin diphosphate (ADP) was infused through the right vertebral artery at the various stages mentioned above, for the purpose of activating platelets, and the basilar artery was then removed. The platelet adhesion or aggregation on the luminal surface was observed quantitatively also by SEM, for evaluating the inhibitory capacity of the endothelial cells upon platelet adhesion or aggregation after SAH. The fold formation of the arterial luminal surface and the ballooning of the endothelial cells were observed initially at 1 hour and 2 days respectively after the 1st cisternal blood injection. The latter findings became most remarkable during the 4 to 7 days after the said blood injection. They were accompanied by intercellular gap formation. None of these findings were seen, however, in the specimens taken 14 days after the said blood injection. In the group with pre-sacrificing ADP infusion, adhesion or aggregation of platelets on the arterial luminal surface was scarcely seen before the second day, but became remarkable 4 to 7 days after the 1st cisternal blood injection, and were reduced by the time 14 days had passed.(ABSTRACT TRUNCATED AT 250 WORDS)