Vasodilatation augments the blood-brain barrier lesions induced by an acute rise in intracarotid pressure.
The vessel wall tension is the product of pressure and internal radius divided by the vessel wall thickness. Hence, dilated vessels will be exposed to higher tension at a given intraluminal pressure. Provided the rise in cerebrovascular intraluminal pressure is sufficiently prominent, transient opening of the morphologic blood-brain barrier will occur. In the present study pressure increase, not sufficient in itself to cause barrier opening, was induced. However, at concomitant dilatation of the vessels--as induced by CO2 or papaverine--under otherwise identical pressure conditions a barrier opening was obtained. Hence, vasodilatation of cerebral vessels will increase their vulnerability to hypertension.
D000818:Animals; D001794:Blood Pressure; D001812:Blood-Brain Barrier; D002339:Carotid Arteries; D008297:Male; D010208:Papaverine / Q000494:pharmacology; D051381:Rats; D013194:Staining and Labeling; D014664:Vasodilation
D010208:Papaverine