title: Neuropeptide Y is a cotransmitter with norepinephrine in guinea pig inferior mesenteric vein.
abstract: Neuropeptide Y (NPY) is a cotransmitter with noradrenaline in guinea pig inferior mesenteric vein. Tyrosine hydroxylase-like immunoreactivity and NPY-like immunoreactivity were colocalized in a dense network of fibers within the adventitial layer of guinea-pig inferior mesenteric vein. Vasoconstrictor responses to electrical field stimulation (0.2-64 Hz, 0.1 ms, 12 V, for 10 s) appear to be mediated primarily by norepinephrine at 0.2 to 4 Hz and by NPY at 8 to 64 Hz. NPY Y1 receptors mediate the contractile responses to both endogenous and exogenous NPY. Norepinephrine and NPY are involved in neuromuscular transmission in guinea pig mesenteric vein suggesting that the sympathetic nervous system requires the coordinated action of norepinephrine and NPY to serve capacitance.
authors.affiliation: Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV 89557-0046, USA.
authors.forename: L
authors.initials: L
authors.lastname: Smyth
authors.forename: J
authors.initials: J
authors.lastname: Bobalova
authors.forename: S M
authors.initials: SM
authors.lastname: Ward
authors.forename: V N
authors.initials: VN
authors.lastname: Mutafova-Yambolieva
mesh_terms: D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D004558:Electric Stimulation; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D008642:Mesenteric Veins / Q000187:drug effects* / Q000294:innervation; D009478:Neuropeptide Y / Q000031:analogs & derivatives / Q000494:pharmacology*; D018377:Neurotransmitter Agents / Q000494:pharmacology*; D009638:Norepinephrine / Q000494:pharmacology*; D012110:Reserpine / Q000494:pharmacology; D013564:Sympathetic Nervous System / Q000502:physiology*; D014661:Vasoconstriction
chemical_list: D000317:Adrenergic alpha-Antagonists; C092926:BIBP 3226; D009478:Neuropeptide Y; D018377:Neurotransmitter Agents; D012110:Reserpine; D001120:Arginine; D009638:Norepinephrine