| Abstract: | Abstract: Acute hypertension was induced by intravenous injection of adrenaline (20 μg/kg) or bicuculline (1.2 mg/kg) in conscious, unrestrained rats with indwelling catheters in aorta and a jugular vein. Three min. after the blood pressure increase, the rats were anaesthetized, and the brains perfused in situ for 1 min. to remove blood and tracers from cerebral vessels. Evans blue-albumin and 125I labelled serum albumin were used as tracers of the blood-brain barrier function. Pretreatment with trifluoperazine, thioridazine, imidazole and desipramine significantly reduced the leakage of albumin into the brain compared to non-treated controls. Acute hypertension enhances pinocytosis activity in cerebral vessels. It is argued that the protective effect of the drugs mentioned may be mediated via an inhibition of the formation of pinocytotic vesicles. |
