Summary
Background and objective: We have evaluated the effects of propofol and its relationship with K+ channels on human isolated umbilical vessels. Methods: Umbilical vessel rings were suspended in isolated organ baths containing Krebs–Ringer solution. In the first series of experiments the effect of propofol (10−9–10−4M) was examined in a concentration-dependent manner on umbilical vessels precontracted with KCl (60 mmol). In the second series, these effects were studied in the presence of tetraethylammonium. Results: A mild contraction was produced by low dose propofol in both precontracted umbilical artery and umbilical vein segments. 10−4M propofol caused significant relaxation in both umbilical artery and umbilical vein. The relaxation response was significantly reduced by the addition of 10−1 M tetraethylammonium. Conclusion: These results suggested that the responses of propofol on KCl-induced contractions of both umbilical artery and vein were dose dependent, and this effect involved Ca2+ activated K+ channels.
