Frieling T, Rupprecht C, Schemann M
Department of Gastroenterology, Heinrich Heine University of Düsseldorf, FRG.
Pharmacology. 1993 Oct;47 Suppl 1:70-6. doi: 10.1159/000139845.
Conventional flux chamber methods were applied to investigate the mode of action of rhein, an active metabolite derived from colonic microbial fermentation of the naturally occurring sennoside laxatives, in muscle-stripped segments of guinea pig colon. Mucosal or serosal application of rhein (10 nmol/1 to 0.5 mmol/l) resulted in a dose-dependent increase in short-circuit current (Isc) that was superimposed by irregular fluctuations in Isc. The response to electrical field stimulation was increased. The rhein-evoked increase in Isc was reduced by serosal addition of 50 mumol/l bumetanide, 1 mumol/l tetrodotoxin, 1 mumol/l atropine and 10 mumol/l piroxicam but not 100 mumol/l hexamethonium, 1 mumol/l ICS 205 930 or 10 mumol/l cimetidine. The study suggests that rhein activates chloride secretion by excitation of submucosal neurons and release of acetylcholine and endogenous prostaglandins, but not by release of histamine or serotonin.
采用传统的通量室方法，研究了大黄酸（一种天然存在的番泻苷泻药经结肠微生物发酵产生的活性代谢产物）对豚鼠结肠肌层剥离段的作用方式。黏膜或浆膜给予大黄酸（10 nmol/l至0.5 mmol/l）会导致短路电流（Isc）呈剂量依赖性增加，且Isc会出现不规则波动。对电场刺激的反应增强。浆膜添加50 μmol/l布美他尼、1 μmol/l河豚毒素、1 μmol/l阿托品和10 μmol/l吡罗昔康可降低大黄酸引起的Isc增加，但100 μmol/l六甲铵、1 μmol/l ICS 205 930或10 μmol/l西咪替丁则无此作用。该研究表明，大黄酸通过刺激黏膜下神经元并释放乙酰胆碱和内源性前列腺素激活氯分泌，但不是通过释放组胺或5-羟色胺。
