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.