Effect of suloctidil on cerebral circulation patterns of conscious rabbits

Suloctidil (SUL) produces calcium antagonistic and antispasmodic effects on peripheral and pial arteries. The present studies were performed with the aim of evaluating the action of SUL on cerebral blood flow (CBF), which was taken as an index for evaluating the cerebral circulation. The drug was administered by rapid intravenous injection to groups of unanaesthetized rabbits at doses of 100-200 micrograms/kg and by intravenous infusion at doses of 10-20 micrograms/kg/min. In other experiments, SUL was chronically administered p.o. to normal rabbits and to rabbits receiving Kritchevsky's atherogenic diet; the daily dose of the drug was about 16 mg/kg. Cerebral blood flow and its compartmental distribution were determined in unanaesthetized animals by the intracarotid 133Xe clearance method. The data demonstrate that the atherogenic diet brings about a significant impairment of CBF; SUL is inactive in normal rabbits, while in the atherosclerotic rabbits it induces a pronounced increase in cerebral blood flow in the grey matter and an enhancement of the corresponding circulatory compartment. These changes are less evident in the white matter.