Cerebroventricular propranolol elevates cerebrospinal fluid norepinephrine and lowers blood pressure.
Ventriculocisternal administration of dl- and d-propranolol produced dose-dependent increases in cerebrospinal fluid norepinephrine and reductions in blood pressure. A highly significant correlation was found between the increase in norepinephrine and the hypotensive effect. The propranolol-induced hypotension was prevented by intracisternal phentolamine. These data indicate that the hypotensive effect of centrally administered propranolol results from a drug-induced release of norepinephrine, which stimulates central alpha receptors to lower arterial pressure.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D004285:Dogs; D007276:Injections, Intraventricular; D007536:Isomerism; D009638:Norepinephrine / Q000134:cerebrospinal fluid*; D011433:Propranolol / Q000008:administration & dosage / Q000494:pharmacology*; D013329:Structure-Activity Relationship
D011433:Propranolol; D009638:Norepinephrine