Article

Neuropeptide Y is a cotransmitter with norepinephrine in guinea pig inferior mesenteric vein

Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV 89557-0046, USA
Peptides (impact factor: 2.43). 07/2000; DOI:10.1016/S0196-9781(00)00217-5 pp.835-843

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.

0 0
 · 
0 Bookmarks
 · 
17 Views
  • Source
    Article: alpha2-Adrenoceptors control the release of noradrenaline but not neuropeptide Y from perivascular nerve terminals.
    M Veronica Donoso, Andrés Carvajal, Alfonso Paredes, Alexander Tomic, Cecilia S Koenig, J Pablo Huidobro-Toro
    [show abstract] [hide abstract]
    ABSTRACT: Neuropeptide Y (NPY) and noradrenaline (NA) are co-transmitters at many sympathetic synapses, but it is not yet clear if their release is independently regulated. To address this question, we quantified the electrically evoked release of these co-transmitters from perivascular nerve terminals to the mesenteric circulation in control and drug-treated rats. 6-Hydroxydopamine reduced the tissue content and the electrically evoked release of ir-NPY and NA as well as the rise in perfusion pressure. A 0.001 mg/kg reserpine reduced the content of ir-NPY and NA, but did not modify their release nor altered the rise in perfusion pressure elicited by the electrical stimuli. However, 0.1mg/kg reserpine reduced both the content and release of NA but decreased only the content but not the release of ir-NPY; the rise in perfusion pressure was halved. Clonidine did not affect the release of ir-NPY while it lowered the outflow of NA, not altering the rise in perfusion pressure elicited by the electrical stimuli. Yohimbine, did not modify the release of ir-NPY but increased the NA outflow, it antagonized the clonidine effect. Therefore, presynaptic alpha2-adrenoceptors modulate the release of NA but not NPY, implying separate regulatory mechanisms.
    Peptides 10/2002; 23(9):1663-71. · 2.43 Impact Factor
  • Source
    Article: 2 -Adrenoceptors control the release of noradrenaline but not neuropeptide Y from perivascular nerve terminals
    M Verónica Donoso, Andrés Carvajal, Alfonso Paredes, Alexander Tomic, Cecilia S Koenig, J Pablo Huidobro-Toro
    [show abstract] [hide abstract]
    ABSTRACT: Neuropeptide Y (NPY) and noradrenaline (NA) are co-transmitters at many sympathetic synapses, but it is not yet clear if their release is independently regulated. To address this question, we quantified the electrically evoked release of these co-transmitters from perivascular nerve terminals to the mesenteric circulation in control and drug-treated rats. 6-Hydroxydopamine reduced the tissue content and the electri-cally evoked release of ir-NPY and NA as well as the rise in perfusion pressure. A 0.001 mg/kg reserpine reduced the content of ir-NPY and NA, but did not modify their release nor altered the rise in perfusion pressure elicited by the electrical stimuli. However, 0.1 mg/kg reserpine reduced both the content and release of NA but decreased only the content but not the release of ir-NPY; the rise in perfusion pressure was halved. Clonidine did not affect the release of ir-NPY while it lowered the outflow of NA, not altering the rise in perfusion pressure elicited by the electrical stimuli. Yohimbine, did not modify the release of ir-NPY but increased the NA outflow, it antagonized the clonidine effect. Therefore, presynaptic 2 -adrenoceptors modulate the release of NA but not NPY, implying separate regulatory mechanisms.
    Peptides 01/2002; 23:1663-1671. · 2.43 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

Keywords

adventitial layer
 
coordinated action
 
dense network
 
electrical field stimulation
 
exogenous NPY
 
guinea pig inferior mesenteric vein
 
guinea pig mesenteric vein
 
guinea-pig inferior mesenteric vein
 
neuromuscular transmission
 
Neuropeptide Y
 
NPY
 
NPY Y1 receptors
 
NPY-like immunoreactivity
 
sympathetic nervous system
 
Tyrosine hydroxylase-like immunoreactivity
 
Vasoconstrictor responses