Positive inotropic effects and receptors of calcitonin gene-related peptide (CGRP) in porcine ventricular muscles.
Calcitonin gene-related peptide (CGRP) in porcine ventricular muscles. positive inotropic effects in the isolated, electrically driven false tendon of the porcine heart. Specific CGRP-binding sites were present in solubilized membrane fractions; the dissociation constant (Kd) and the maximum binding (Bmax) were 50.4 pM and 180 fmol/mg protein, respectively. SDS-PAGE analysis of CGRP-binding sites revealed the molecular mass of 70 K and 120 K. Few CGRP-like immunoreactive nerves were present in the ventricular muscle layer. These results indicate that CGRP activates specific receptor sites on the ventricular muscles and causes positive inotropic responses. CGRP receptors in ventricles are likely to be activated by circulating CGRP.
Miyauchi
T
T
Department of Internal Medicine, University of Tsukuba, Japan.
Sano
Y
Y
Hiroshima
O
O
Yuzuriha
T
T
Sugishita
Y
Y
Ishikawa
T
T
Saito
A
A
Goto
K
K
D000818:Animals; D001667:Binding, Competitive; D002116:Calcitonin / Q000378:metabolism*; D015740:Calcitonin Gene-Related Peptide; D002316:Cardiotonic Agents / Q000502:physiology*; D006352:Heart Ventricles / Q000378:metabolism; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology; D009200:Myocardial Contraction / Q000187:drug effects; D009479:Neuropeptides / Q000378:metabolism / Q000502:physiology*; D011690:Purkinje Fibers / Q000378:metabolism; D018003:Receptors, Calcitonin; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000302:isolation & purification*; D013552:Swine; D016276:Ventricular Function
D002316:Cardiotonic Agents; D009479:Neuropeptides; D018003:Receptors, Calcitonin; D011956:Receptors, Cell Surface; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide; D007545:Isoproterenol