title: Potential histamine H2-receptor antagonists. 2. N-alpha-Guanylhistamine.
abstract: The agonist molecule, histamine, has been used as a starting point for the design of potential H2-receptor antagonists. Converting the side-chain amino group into a guanidine yielded the first histamine H2-receptor antagonist, Nalpha-guanylhistamine. Antagonism of H2 receptors was demonstrated by the inhibition of histamine-stimulated gastric acid secretion in the rat at high dose levels (approximate ID50 800 MUmol/kg, iv) and by the inhibition of histamine-stimulated tachycardia of guinea-pig right atrium (pA2 equals 3.9). Guanylhistamine behaves as a partial agonist at histamine H2 receptors.
mesh_terms: D000818:Animals; D005750:Gastric Juice / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism; D006146:Guanidines / Q000138:chemical synthesis / Q000494:pharmacology; D006147:Guanine / Q000138:chemical synthesis / Q000494:pharmacology; D006168:Guinea Pigs; D006325:Heart Atria / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006632:Histamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D006634:Histamine H1 Antagonists / Q000138:chemical synthesis*; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D051381:Rats; D011955:Receptors, Drug; D012636:Secretory Rate / Q000187:drug effects
chemical_list: D006146:Guanidines; D006634:Histamine H1 Antagonists; D011955:Receptors, Drug; D006147:Guanine; D006632:Histamine