title: [Imidazole H2-antagonists and H2-angonists: effects of 5-alkyl substitution].
abstract: The effects of some imidazole derivatives, H2-antagonists and H2-agonists, with different alkyl groups in 5-position (R = Me, Et, i.Pr), were studied comparatively on cat gastric secretion and guinea-pig gastric fundus. The antagonistic and agonistic activities decrease with increase in the substituent inductive effect, and, in particular, it should be noted that the cimetidine ethyl analog (compound V) is a competitive antagonist of H2-histamine receptors. More hypotheses on the H1- and H2-receptor surfaces are proposed.
mesh_terms: D000478:Alkylation; D000818:Animals; D002415:Cats; D005750:Gastric Juice / Q000378:metabolism; D006168:Guinea Pigs; D006635:Histamine H2 Antagonists; D007093:Imidazoles / Q000494:pharmacology*; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D011968:Receptors, Histamine / Q000187:drug effects*; D011970:Receptors, Histamine H2 / Q000187:drug effects*; D013270:Stomach / Q000187:drug effects; D013329:Structure-Activity Relationship
chemical_list: D006635:Histamine H2 Antagonists; D007093:Imidazoles; D011968:Receptors, Histamine; D011970:Receptors, Histamine H2
vernacular_title: H2-antagonisti ed H2-agonisti imidazolici: effetti della 5-alchilostituzione.