CGRP antagonist activity of short C-terminal fragments of human alpha CGRP, CGRP(23-37) and CGRP(19-37).
The activity of short C-terminal fragments of human alpha calcitonin gene-related peptide (CGRP), CGRP(19-37), and CGRP(23-37), and of the N-terminally acetylated (Ac) derivative, AcCGRP(19-37), has been investigated in the guinea pig isolated left atria (electrically driven) for their ability to antagonize the positive inotropic effect of human alpha CGRP. All the peptides tested produced a rightward displacement of the curve to the agonist without depressing the maximal response: apparent pA2 values were 5.39 and 4.81 for CGRP(19-37) and CGRP(23-37), respectively, as compared to 6.81 for CGRP(8-37). AcCGRP(19-37) was a more potent antagonist than the parent peptide, with an apparent pA2 value of 6.03.
Rovero
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P
Chemistry and Pharmacology Department, A. Menarini Pharmaceuticals, Florence, Italy.
Giuliani
S
S
Maggi
C A
CA
D000818:Animals; D016275:Atrial Function; D015740:Calcitonin Gene-Related Peptide / Q000494:pharmacology* / Q000502:physiology; D006168:Guinea Pigs; D006325:Heart Atria / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects / Q000502:physiology; D010446:Peptide Fragments / Q000494:pharmacology*; D018003:Receptors, Calcitonin; D011956:Receptors, Cell Surface / Q000037:antagonists & inhibitors* / Q000502:physiology
D010446:Peptide Fragments; D018003:Receptors, Calcitonin; D011956:Receptors, Cell Surface; C079069:calcitonin gene related peptide (19-37); C079068:calcitonin gene-related peptide (23-37); D015740:Calcitonin Gene-Related Peptide