conclusions the application of 5-ht1a, 5-ht2, 5-ht3, 5-ht4, 5-ht6 and 5-ht7 receptor antagonists, applied at concentrations lower than 1.0 µm did not modify the efs-induced contraction and relaxation responses, whichsuggests the unlikely involvement of endogenous 5-ht in mediating responses to efs in the described test conditions. materials and methods segments taken from the rat duodenum, jeju...