Specific antagonists for the myotropic action of angiotensin II and angiotensin I on the isolated rat colon.
Substitutions of 8 phenylalanine with L-alanine and D-phenylalanine abolish the myotropic action of the angiotensin II (AT(II)) analogues and confer inhibitory properties on the molecule. [8-L-Ala]-AT(II) and [8-D-Phe]-AT(II) antagonize specifically the myotropic action of AT(II) and angiotensin I (AT(I)) on the rat colon, while the action of other myotropic agents (acetylcholine, 5 hydroxytryptamine) is not modified.
D000596:Amino Acids / Q000494:pharmacology; D000804:Angiotensin II / Q000037:antagonists & inhibitors*; D000818:Animals; D003106:Colon / Q000187:drug effects*; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D010649:Phenylalanine / Q000494:pharmacology; D051381:Rats; D013329:Structure-Activity Relationship
D000596:Amino Acids; D000804:Angiotensin II; D010649:Phenylalanine