CLINICAL EFFECT OF ACUTE BLOOD-PRESSURE INCREASE IN CONSCIOUS RATS - COMPARISON BETWEEN NORMOTENSIVE AND SPONTANEOUSLY HYPERTENSIVE RATS

Abrupt blood pressure rise induced by vasoactive substances or by compression of the thoracic aorta can result in multifocal areas of protein extravasation in the brain, i.e., damage to the blood-brain barrier (BBB) as a result of mechanical stress on the vessels causing increased permeability. The correlation between BBB lesions and convulsions after acute blood pressure rise in conscious normotensive rats (NR) and spontaneously hypertensive rats (SHR) was reported. The decreased vulnerability of the cerebral vessels as far as BBB lesions are concerned in SHR is probably due to structural adaptation of the resistance vessels and is in agreement with the clinical observation hat hypertensive encephalopathy is comparatively rare in patients with established benign essential hypertension.