Wallerstedt S M, Törnebrandt K, Bodelsson M
Department of Anaesthesia and Intensive Care, University Hospital, Lund, Sweden.
Br J Anaesth. 1998 May;80(5):655-9. doi: 10.1093/bja/80.5.655.
We have investigated the relaxant effects of propofol on smooth muscle tension in human omental arteries and veins to determine if endothelium-related mechanisms are involved. Isolated vessel segments were precontracted with endothelin-1 and propofol was added cumulatively (10(-7)-10(-4) mol litre-1). In both artery and vein segments, propofol induced relaxation, which was not dependent on an intact endothelium. Relaxation was reduced when the extracellular K+ concentration was increased and in the presence of tetraethylammonium chloride (TEA). In intact segments, N-nitro-L-arginine methyl ester (L-NAME), indomethacin, glibenclamide, 4-aminopyridine, clotrimazole and atropine did not affect the concentration-response curve of propofol. This indicates that propofol relaxes human omental arteries and veins in an endothelium independent manner, and that hyperpolarization caused by activation of the K+ channel, BKCa, may be involved.
我们研究了丙泊酚对人网膜动脉和静脉平滑肌张力的舒张作用，以确定是否涉及内皮相关机制。分离的血管段先用内皮素-1预收缩，然后累积加入丙泊酚（10^(-7)-10^(-4) mol/L）。在动脉和静脉段中，丙泊酚均引起舒张，且不依赖于完整的内皮。当细胞外钾离子浓度升高以及存在四乙铵（TEA）时，舒张作用减弱。在完整的血管段中，N-硝基-L-精氨酸甲酯（L-NAME）、吲哚美辛、格列本脲、4-氨基吡啶、克霉唑和阿托品均不影响丙泊酚的浓度-反应曲线。这表明丙泊酚以不依赖内皮的方式舒张人网膜动脉和静脉，并且可能涉及由大电导钙激活钾通道（BKCa）激活引起的超极化。
