Thimerosal blocks stimulated but not basal release of endothelium‐derived relaxing factor (EDRF) in dog isolated coronary artery

Abstract

The effect of an acetly‐coA lysolecithin acyltransferase inhibitor, thimerosal, on the release of endothelium‐derived relaxing factor (EDRF) was examined in the greyhound isolated coronary artery. Thimerosal (1–10 μm) relaxed fully, ring segments of coronary artery which were contracted with the thromboxane A2‐mimetic, U46619 (30 nm). The response was endothelium‐dependent, slow in both onset and time to reach maximum. The maximum relaxation to the highest concentration of thimerosal (10 μm) was maintained for 10–20 min before the tissue slowly regained active force (1–2 h) to the same or higher level as that prior to the addition of thimerosal. At this time the endothelium‐dependent relaxat..