Tyramine-induced release of neuropeptide Y (NPY) in isolated rabbit intestine.
The effect of tyramine on the contractile activity of rabbit ileal segments was studied. Treatment with tyramine initiated a short-lived, fast contraction followed first by a relaxation then by a subsequent sustained contracture. Although the mechanism of the initial fast contraction remains obscure, the relaxation was abolished by the pretreatment with a combination of phentolamine and propranolol and the sustained contracture was blocked by neuropeptide Y (NPY)-antiserum. The inhibitory effect of the NPY-antiserum was produced in a dose-dependent manner. Thus, it is suggested that tyramine induced the release of NPY to initiate the subsequent sustained contracture.
D000818:Animals; D005260:Female; D007082:Ileum / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009478:Neuropeptide Y; D010646:Phentolamine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011817:Rabbits; D014439:Tyramine / Q000494:pharmacology*
D009419:Nerve Tissue Proteins; D009478:Neuropeptide Y; D011433:Propranolol; D014439:Tyramine; D010646:Phentolamine