曼氏血吸虫（吸虫纲：复殖目）分离出的肌纤维的胆碱能抑制作用

Cholinergic inhibition of muscle fibres isolated from Schistosoma mansoni (Trematoda:Digenea).

作者信息

Day T A, Chen G Z, Miller C, Tian M, Bennett J L, Pax R A

机构信息

Department of Pharmacology and Toxicology, Michigan State University, East Lansing 48824, USA.

出版信息

Parasitology. 1996 Jul;113 ( Pt 1):55-61. doi: 10.1017/s0031182000066270.

DOI:10.1017/s0031182000066270

PMID:8710415

Abstract

Cholinergic compounds inhibit FMRFamide-induced contractions in dispersed muscle fibres isolated from adult Schistosoma mansoni. Acetylcholine (ACh) was the most effective cholinergic agonist tested with an EC50 < 100 nM. Less effective were propionylcholine and arecoline with EC50 < 1 microM and butyrylcholine and carbachol with EC50 < 10 microM. Choline, muscarine, pilocarpine, nicotine, DMPP (1,1-dimethylphenylpiperazine) and levamisole were all ineffective. Amongst tested antagonists, d-tubocurarine (100 microM), mecamylamine (1 mM), scopolamine (1 mM) and quinuclidinyl benzilate (10 microM) were all ineffective. Bicuculline, picrotoxin and strychnine were also ineffective. However alpha-bungarotoxin, at 100 nM, was able to block the inhibitory ACh effect. From these data it appears that the cholinergic receptor on the schistosome muscle fibres may be of the nicotinic type, but that its pharmacology is different from that of nicotinic receptors of vertebrates as well as of nematodes or a variety of other invertebrates.

摘要

胆碱能化合物可抑制从曼氏血吸虫成虫分离出的分散肌纤维中FMRF酰胺诱导的收缩。乙酰胆碱（ACh）是所测试的最有效的胆碱能激动剂，其半数有效浓度（EC50）<100 nM。丙酰胆碱和槟榔碱的效果较差，EC50<1 microM，丁酰胆碱和卡巴胆碱的EC50<10 microM。胆碱、毒蕈碱、毛果芸香碱、尼古丁、DMPP（1,1-二甲基苯基哌嗪）和左旋咪唑均无效。在所测试的拮抗剂中，筒箭毒碱（100 microM）、美加明（1 mM）、东莨菪碱（1 mM）和苯甲托品（10 microM）均无效。荷包牡丹碱、印防己毒素和士的宁也无效。然而，100 nM的α-银环蛇毒素能够阻断ACh的抑制作用。从这些数据来看，血吸虫肌纤维上的胆碱能受体可能是烟碱型的，但其药理学特性与脊椎动物、线虫或其他多种无脊椎动物的烟碱型受体不同。