Scott T M, Chafe L
Faculty of Medicine, Memorial University of Newfoundland, St. John's, Canada.
Artery. 1994;21(5):271-86.
Using L-NAME and the potassium channel blocker apamin we have investigated the component of acetylcholine-induced vascular relaxation lost when the mesenteric arterial bed is denervated. We have confirmed that vascular denervation produces a reduction of up to 35% in the ability of ACh to cause relaxation in the presence of the alpha agonists methoxamine and cirazoline. A single 30 minute exposure to L-NAME reduced the relaxation to ACh by up to 44% in control vascular preparations and by 85% in denervated preparations. In control preparations, prolonged exposure to L-NAME reduced the relaxation to ACh by up to 66% and by 77% in the presence of apamin. In denervated preparations prolonged exposure to L-NAME reduced the relaxation to ACh by 96%. The almost complete loss of acetylcholine-induced relaxation following prolonged exposure to L-NAME (96.6% in methoxamine and 93.9% in cirazoline) in denervated preparations suggests that innervation is involved in the expression of the L-NAME-resistant relaxation to acetylcholine in the superior mesenteric arterial bed of the rat.
我们使用L-硝基精氨酸甲酯（L-NAME）和钾通道阻滞剂蜂毒明肽，研究了肠系膜动脉床去神经支配后乙酰胆碱诱导的血管舒张作用中丧失的成分。我们证实，在存在α受体激动剂甲氧明和可乐定的情况下，血管去神经支配会使乙酰胆碱引起舒张的能力降低高达35%。在对照血管制剂中，单次30分钟暴露于L-NAME会使对乙酰胆碱的舒张反应降低高达44%，而去神经支配的制剂中则降低85%。在对照制剂中，长时间暴露于L-NAME会使对乙酰胆碱的舒张反应降低高达66%，在存在蜂毒明肽的情况下降低77%。在去神经支配的制剂中，长时间暴露于L-NAME会使对乙酰胆碱的舒张反应降低96%。在去神经支配的制剂中，长时间暴露于L-NAME后乙酰胆碱诱导的舒张作用几乎完全丧失（甲氧明存在时为96.6%，可乐定存在时为93.9%），这表明神经支配参与了大鼠肠系膜上动脉床中对L-NAME耐药的乙酰胆碱舒张反应的表达。
