title: Alpha 2-adrenoceptor-mediated inhibition of nerve stimulation-evoked release of neuropeptide Y (NPY)-like immunoreactivity in the pithed guinea-pig.
abstract: Clonidine (10 micrograms X kg-1) reduced by almost 50% the increase in plasma neuropeptide (NPY)-like immunoreactivity (-LI) induced by preganglionic nerve stimulation at 8 Hz. This effect was reversed by yohimbine (1 mg X kg-1) which caused a three-fold increase of the plasma NPY-LI. Prazosin (1 mg X kg-1) had no such effect. Guanethidine (5 mg X kg-1) reduced the stimulation-evoked increase in plasma NPY-LI. It is concluded that the release of NPY-LI evoked by nerve stimulation from sympathetic nerve terminals is controlled by a presynaptic alpha 2-adrenoceptor-mediated mechanism.
mesh_terms: D000818:Animals; D001794:Blood Pressure; D003655:Decerebrate State; D004558:Electric Stimulation; D006168:Guinea Pigs; D006339:Heart Rate; D008297:Male; D009474:Neurons / Q000502:physiology*; D009478:Neuropeptide Y / Q000378:metabolism*; D011942:Receptors, Adrenergic, alpha / Q000502:physiology*
chemical_list: D009478:Neuropeptide Y; D011942:Receptors, Adrenergic, alpha