Effect of aligeron on the cerebral venous outflow and cerebrospinal fluid pressure in dogs.

The effect of Aligeron (1-benzhydril-4-allyl-piperazine dihydrochloride) on the cranial circulation was studied in dogs under chloralose-urethan anaesthesia. The parameters followed were: venous outflow from the confluence of the cerebral sinusses (CVO), cerebrospinal fluid pressure in cysterna magna (CSFP), systemic arterial blood pressure (BP) and pulse rate (PR). CVP was measured using the technique of Rapela and Green (1964). Aligeron was applied at doses of 5 and 10 mg/kg i.v. Papaverine hydrochloride was used as a reference compound. aligeron administration at a dose of 5 mg/kg led to quick increase of the CVO with a duration of the effect approximately 30 min. CSFP also increased in a similar way. BP and PR showed insignificant changes. The administration of 10 mg/kg did not lead to an increase of its effect on CVO. Papaverine (1 mg/kg i.v.) had a weaker effect than that of Aligeron. According to the classical concepts the changes observed in our experiments were due to the cerebral vasodilator effect of Aligeron which caused a fall in cerebrovascular resistance and an increase of the intracranial blood volume. Our experiments suggest that Aligeron influenced the resistance vessels more than the capacitance ones.