Süer, CErenmemisoglu, ATemocin, SAkar, SBeydagi, HTaspolat, I1992-07-012009-06-011992-07-012009-06-011992-07-01Süer C, Erenmemisoglu A, Temocin S, Akar S, Beydagi H, Taspolat I. Influence of calcium removal from bath solution on isolated rat duodenum contractions. Indian Journal of Physiology and Pharmacology. 1992 Jul; 36(3): 181-4http://imsear.searo.who.int/handle/123456789/108988In this study whether extracellular Ca++ is essential to produce an increase of tension of isolated rat duodenum by ACh, 5-HT, AVP and KCl-, was examined. KCl- and AVP-evoked contractions were almost totally prevented by Ca++ removal from bath solution. The increase of tension of isolated duodenum caused by ACh or 5-HT was totally prevented after adding nifedipine, a Ca++ channel blocker, into Ca free solution. Our results suggest that ACh or 5-HT utilizes intracellular as well as extracellular sources of Ca++ to produce contraction in rat duodenum, whereas AVP-or KCl evoked contraction was mainly due to influx of Ca from extracellular sources.engAcetylcholine --pharmacologyAnimalsArginine Vasopressin --pharmacologyCalcium --pharmacologyDuodenum --drug effectsMuscle Contraction --drug effectsMuscle, Smooth --drug effectsNifedipine --pharmacologyPotassium Chloride --pharmacologyRatsSerotonin --pharmacologyIn Vitro