Effects of propofol on isolated human pial arteries

Background: The intravenous anaesthetic propofol has been reported to incre ase cerebral vascular resistance in vivo. The underlying mechanisms are not fully understood, but may include effects on metabolism and direct effects on the vascular smooth muscle. The present study was designed to evaluate the direct effects of propofol on human pial arteries. Methods: We investigated the direct effect of propofol (10(-6) 10(-4) M) on isolated human pial arteries at basal tension as well as the influence on contractions induced by 5-hydroxytryptamine, prostaglandin F-2 alpha noradr enaline and potassium chloride. Results: Propofol did not change the basal tension. Propofol at 10(-6) and 10(-5) M did not affect the concentration-response curves of any of the con tractile agents tested. Propofol at the supraclinical concentration 10(-4) M reduced the contractions induced by all contractile agents. Conclusion: Propofol reduces the tone of human pial arteries in vitro at su praclinical concentrations, but has no effect on the tone at clinically rel evant concentrations.