title: [Imidazolic H2-agonists: importance of 2-amino substitution for pharmacological activity].
abstract: The results of 2-aminohistamine (compound I) and 2-amino-5-methylhistamine (compound II) on cat acid secretion and on guinea pig gall-bladder motility are described and compared with those of Histamine or Dimaprit. The compound (I) showed a greater H2- than H1-receptor stimulating activity, while compound (II), inactive on H1, was effective on H2-receptors, being endowed with a less "potency" and "efficacy" than compound (I). The pharmacological activities of both compounds, related to their chemical structure, are discussed.
mesh_terms: D000818:Animals; D001681:Biological Assay; D002415:Cats; D017259:Dimaprit; D005744:Gastric Acid / Q000378:metabolism; D006168:Guinea Pigs; D006632:Histamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D008761:Methylhistamines / Q000494:pharmacology*; D009126:Muscle Relaxation / Q000187:drug effects; D011738:Pyrilamine / Q000494:pharmacology; D011968:Receptors, Histamine / Q000378:metabolism*; D011969:Receptors, Histamine H1 / Q000378:metabolism; D011970:Receptors, Histamine H2 / Q000378:metabolism*; D013329:Structure-Activity Relationship; D013890:Thiourea / Q000494:pharmacology; D001743:Urinary Bladder / Q000187:drug effects
chemical_list: D008761:Methylhistamines; D011968:Receptors, Histamine; D011969:Receptors, Histamine H1; D011970:Receptors, Histamine H2; C040847:2-aminohistamine; D006632:Histamine; C041798:2-amino-5-methylhistamine; D013890:Thiourea; D011738:Pyrilamine; D017259:Dimaprit
vernacular_title: H2-agonisti imidazolici: importanza della 2-aminosostituzione per l'attivita' farmacologica.