The effect of lipid peroxides on isolated human umbilical artery contraction

OBJECTIVE: Our purpose was to determine the effect of oxidized lipids on the contractile activity of isolated human umbilical arteries. STUDY DESIGN: Umbilical artery rings were prepared for isometric tension recording and exposed to cumulative concentrations of oxidized and nonoxidized lipid and control solutions. Rings were also incubated with the lipid or control solutions and then contracted with cumulative concentrations of U46619. A final set of rings in Ca++-free depolarized solution was incubated with the agents above, and then the Ca++ concentration was increased cumulatively. RESULTS: The lipids had no direct contractile effect. Both lipids inhibited the response to U46619 and Ca++, with the oxidized lipids having the most significant effect. CONCLUSION: Oxidized lipids lack a direct contractile effect on isolated human umbilical arteries and inhibit the contractile response to thromboxane and calcium