title: Competitive and stereoselective histamine H1 antagonistic effect of cicletanide in guinea-pig isolated ileum.
abstract: The histamine H1 antagonistic effects of the racemic form and the enantiomers of cicletanide, a new antihypertensive furopyridine derivative, were investigated in guinea-pig isolated ileum. Both the racemic and the (-) enantiomer behaved as competitive histamine antagonists (pA2 values of 6.8 and 7.2, respectively). The (+) enantiomer was at least 100 times less potent than the (-) enantiomer. The H1-blocking effect of cicletanide is the most potent and is the only stereoselective property so far reported for the drug.
mesh_terms: D000818:Animals; D004232:Diuretics / Q000494:pharmacology*; D005260:Female; D006168:Guinea Pigs; D006634:Histamine H1 Antagonists; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D011725:Pyridines; D013237:Stereoisomerism
chemical_list: D004232:Diuretics; D006634:Histamine H1 Antagonists; D011725:Pyridines; C038068:cicletanine