Toda N, Ayajiki K
Department of Pharmacology, Shiga University of Medical Sciences, Ohtsa, Japan.
Am J Physiol. 1990 Apr;258(4 Pt 2):H983-6. doi: 10.1152/ajpheart.1990.258.4.H983.
Helical strips of bovine basilar arteries responded to transmural electrical stimulation with moderate relaxations that were abolished by treatment with tetrodotoxin and oxyhemoglobin and were significantly attenuated by quinidine, as were the relaxations previously seen in dog and monkey cerebral arteries. The relaxant response of the bovine arteries was attenuated by treatment with acetylcholine and physostigmine and was significantly potentiated by atropine. In contrast, relaxations of dog coronary arteries to transmural stimulation, mediated via beta-adrenoceptors, were not influenced by physostigmine and atropine but were attenuated by acetylcholine. Abundant fibers containing cholinesterase were histologically demonstrated in bovine basilar arteries, suggesting the presence of cholinergic innervation. Acetylcholine liberated from the cholinergic nerve appears to act on muscarinic receptors located in vasodilator nerve terminals in bovine cerebral arteries and to interfere with the release of vasodilator transmitters.
牛基底动脉的螺旋条对跨壁电刺激产生适度舒张反应，该反应可被河豚毒素和氧合血红蛋白处理消除，且被奎尼丁显著减弱，就像之前在犬和猴脑动脉中观察到的舒张反应一样。牛动脉的舒张反应可被乙酰胆碱和毒扁豆碱处理减弱，并被阿托品显著增强。相比之下，犬冠状动脉对跨壁刺激的舒张反应是通过β-肾上腺素能受体介导的，不受毒扁豆碱和阿托品影响，但被乙酰胆碱减弱。组织学证明牛基底动脉中有大量含胆碱酯酶的纤维，提示存在胆碱能神经支配。从胆碱能神经释放的乙酰胆碱似乎作用于牛脑动脉中位于血管舒张神经末梢的毒蕈碱受体，并干扰血管舒张递质的释放。
