title: The action of angiotensin on the human colon in vitro.
abstract: 1. The action of angiotensin on the circular and longitudinal muscle of the human colon has been studied in vitro. The ED50 value (g/ml) of circular muscle was 8.7 x 10(-8) and of longitudinal muscle 3.1 x 10(-8), while the corresponding figures for acetylcholine were 1.6 x 10(-6) and 1.1 x 10(-6), respectively. Angiotensin caused a sustained contraction associated with prolonged tachyphylaxis.2. As the action of angiotensin was not antagonized by atropine, hexa-methonium or procaine, angiotensin appeared to act directly on the smooth muscle of the human colon.3. Lidoflazine is not a specific antagonist of angiotensin.
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000804:Angiotensin II / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D001285:Atropine / Q000494:pharmacology; D003106:Colon / Q000187:drug effects*; D006584:Hexamethonium Compounds / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000187:drug effects; D010879:Piperazines / Q000494:pharmacology; D011343:Procaine / Q000494:pharmacology; D013618:Tachyphylaxis; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D006584:Hexamethonium Compounds; D010879:Piperazines; D014665:Vasodilator Agents; D000804:Angiotensin II; D011343:Procaine; D001285:Atropine; D000109:Acetylcholine