Sánchez de Medina F, Gálvez J, González M, Zarzuelo A, Barrett K E
Department of Pharmacology, School of Pharmacy, University of Granada, Spain.
Life Sci. 1997;61(20):2049-55. doi: 10.1016/s0024-3205(97)00863-1.
The effect of the flavonoid quercetin on epithelial chloride secretion has been studied in vitro. These studies were performed using monolayers of the human colonic epithelial cell line T84, mounted in modified Ussing chambers. Chloride secretion was assessed as changes in short circuit current (I(SC)) both in basal conditions as well as in response to different secretagogues: carbachol (100 microM), vasoactive intestinal polypeptide (VIP) (10 nM) and prostaglandin E2 (1 microM). Secretion was also induced via protein kinase C by adding phorbol myristate acetate (PMA, 100 nM) in the presence of the calmodulin inhibitor W13 (50 microM). Quercetin (100 microM) was able to promote secretion when the flavonoid was added to the mucosal side of the monolayer. On the contrary, serosal addition of quercetin was devoid of secretory activity and at concentration of 10 microM it was able to inhibit chloride secretion in response to carbachol, prostaglandin E2 and PMA/W13, but not that induced by VIP. We conclude that the effect of quercetin on epithelial chloride secretion is dual, secretory and antisecretory, depending on both the concentration and the side of the monoloayer where the addition of the flavonoid is made.
黄酮类化合物槲皮素对上皮细胞氯分泌的作用已在体外进行了研究。这些研究使用了人结肠上皮细胞系T84的单层细胞，将其安装在改良的尤斯灌流小室中。氯分泌通过短路电流（I(SC)）的变化来评估，包括基础条件下以及对不同促分泌剂的反应：卡巴胆碱（100微摩尔）、血管活性肠肽（VIP）（10纳摩尔）和前列腺素E2（1微摩尔）。在钙调蛋白抑制剂W13（50微摩尔）存在的情况下，通过添加佛波醇肉豆蔻酸酯乙酸酯（PMA，100纳摩尔）经蛋白激酶C诱导分泌。当将槲皮素（100微摩尔）添加到单层细胞的黏膜侧时，它能够促进分泌。相反，在浆膜侧添加槲皮素没有分泌活性，并且在浓度为10微摩尔时，它能够抑制对卡巴胆碱、前列腺素E2和PMA/W13的氯分泌反应，但不能抑制由VIP诱导的氯分泌。我们得出结论，槲皮素对上皮细胞氯分泌的作用是双重的，即分泌和抗分泌作用，这取决于黄酮类化合物添加的浓度以及单层细胞的添加侧。
