Kuwahara A, Cooke H J
Department of Physiology, Ohio State University, Columbus.
J Pharmacol Exp Ther. 1990 Jan;252(1):1-7.
The effects of substance P and related tachykinins on short-circuit current were determined in submucosa-mucosa sheets of guinea pig distal colon. Substance P, neurokinin A, eledoisin and physalaemin evoked a concentration-dependent increase in short-circuit current with a rank order of potencies of substance P = physalaemin greater than eledoisin = neurokinin A. The substance P response was reduced in chloride-free solutions or after addition of furosemide. Tetrodotoxin, atropine, mecamylamine and pyrilamine reduced the response to substance P. The substance P antagonist, [D-Arg1,D-Phe5,Trp7,9,Leu11]-substance P, reduced the response to neural stimulation and to exogenous substance P. The results suggest that substance P evokes anion secretion by activating cholinergic and noncholinergic neurons and by releasing histamine.
在豚鼠远端结肠的黏膜下层-黏膜片层中测定了P物质及相关速激肽对短路电流的影响。P物质、神经激肽A、伊列替丁和 Physalaemin 引起短路电流呈浓度依赖性增加，其效价顺序为：P物质=Physalaemin＞伊列替丁=神经激肽A。在无氯溶液中或加入呋塞米后，P物质的反应减弱。河豚毒素、阿托品、美加明和吡苄明降低了对P物质的反应。P物质拮抗剂[D-Arg1,D-Phe5,Trp7,9,Leu11]-P物质降低了对神经刺激和外源性P物质的反应。结果表明，P物质通过激活胆碱能和非胆碱能神经元以及释放组胺来引起阴离子分泌。
