Vasoconstriction of carotid artery induced by hydroperoxides

Abstract

The influence of hydroperoxides (H2O2, t-butylhydroperoxide) on tone of arterial smooth muscle was studied. Experiments performed with segments of rabbit carotid arteries under isometric conditions show that peroxide concentrations > 10-4 M induced vasoconstriction. These contractions were reversible when glucose was present in the superfused solution. In the absence of glucose a long-lasting increase in tone was found. The contraction response persisted even in Ca2+-free solution. Evidently, hydroperoxides have a stimulatory effect on vascular smooth muscle probably related to a liberation of intracellularly bound Ca2+.