EVIDENCE FOR THE PARTICIPATION OF VASCULAR ENDOTHELIUM ORIGINATED HUMORAL-FACTORS TO CEREBRAL VASOSPASM

Vascular endothelium synthetizes mediators which either cause vasorela xation or vasoconstriction. The purpose of this study is to investigat e the role of these mediators in the pathogenesis of cerebral vasospas m. An inhibitor of endothelium-derived relaxing factor is haemoglobin; endothelium removal by triton X-100 and endothelin-1 caused narrowing in the diameter of basilar artery of the rabbit. The pathological, ul trastructural investigations and computerized tomography images are in accordance with this finding. These results indicate that not only an increase in vasoconstrictor mediator level but also the lack of endot helium-derived relaxing mediators are responsible of the spasm of the basilar artery.