Scheurer U, Varga L, Drack E, Bürki H R, Halter F
Am J Physiol. 1983 Mar;244(3):G266-72. doi: 10.1152/ajpgi.1983.244.3.G266.
The mechanism of action of cholecystokinin octapeptide (CCK-OP) on tonic and phasic contraction of antral, pyloric, and duodenal smooth muscles was studied with a novel perfusion manometric system in isolated esophagogastroduodenal preparations of the rat. CCK-OP increased baseline pressure at each site, frequencies of phasic contractions in the antrum and pylorus, and amplitudes in the duodenum. It decreased antral and pyloric amplitudes and frequency of duodenal phasic contractions. CCK-OP action on tonic contraction was tetradotoxin (TTX) susceptible and its action on phasic contractions was TTX resistant. Phentolamine, phenoxybenzamine, propranolol, catecholamine depletion of preparations by reserpine-tetrabenazine, and the block of catecholamine synthesis at different levels significantly inhibited CCK-OP-induced tonic contraction, whereas atropine had no influence. Adrenergic and cholinergic neural actions on phasic contractions altered the level of amplitudes and frequencies on which CCK-OP action occurred. It is concluded that CCK-OP action on tonic contraction of the rat gastroduodenal junction is mediated by a neural noncholinergic pathway, whereas its effect on muscles responsible for phasic contractions is a direct one.
采用一种新型灌注测压系统，在大鼠离体食管胃十二指肠标本上，研究了胆囊收缩素八肽（CCK-OP）对胃窦、幽门和十二指肠平滑肌紧张性和节律性收缩的作用机制。CCK-OP增加了各部位的基础压力、胃窦和幽门的节律性收缩频率以及十二指肠的收缩幅度。它降低了胃窦和幽门的收缩幅度以及十二指肠节律性收缩的频率。CCK-OP对紧张性收缩的作用对河豚毒素（TTX）敏感，而其对节律性收缩的作用对TTX有抗性。酚妥拉明、酚苄明、普萘洛尔、利血平-丁苯那嗪使标本儿茶酚胺耗竭以及在不同水平阻断儿茶酚胺合成，均显著抑制CCK-OP诱导的紧张性收缩，而阿托品无影响。肾上腺素能和胆碱能神经对节律性收缩的作用改变了CCK-OP发挥作用时的收缩幅度和频率水平。得出结论：CCK-OP对大鼠胃十二指肠连接处紧张性收缩的作用是由神经非胆碱能途径介导的，而其对负责节律性收缩的肌肉的作用是直接的。
