Neuropeptide Y Y1 receptors are involved in the vasoconstriction caused by human sympathetic nerve stimulation.
Neuropeptide Y, a novel neurotransmitter, interacts with selective membrane receptors to cause vasoconstriction. Frequency- and concentration-dependent isometric contractions were observed in human inferior mesenteric artery and vein mounted rings that were stimulated with either electrical pulses (70 V, 0.5 ms, 2.5-20 Hz) or noradrenaline. The antagonism elicited by 100 nM tetrodotoxin and 1 microM guanethidine confirmed the neuronal and sympathetic origins of the vasomotor response. Incubation with BIBP 3226 ((R)-N2-(di-phenacetyl)-N-(4-hydroxyphenyl)-methyl-D-arginineam ide), a selective neuropeptide Y Y1 receptor antagonist, significantly reduced the vasoconstriction. The incomplete antagonist activity of BIBP 3226 tends to support the hypothesis of sympathetic co-transmission involving neuropeptide Y, adenosine 5'-triphosphate and noradrenaline. These findings were confirmed in parallel studies using rat superior mesenteric artery and vein ring preparations.
Racchi
H
H
Department of Physiology, Faculty of Biological Sciences, P. Universidad Católica de Chile, Santiago.
Schliem
A J
AJ
Donoso
M V
MV
Rahmer
A
A
Zúñiga
A
A
Guzmán
S
S
Rudolf
K
K
Huidobro-Toro
J P
JP
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D004558:Electric Stimulation; D006801:Humans; D066298:In Vitro Techniques; D008638:Mesenteric Arteries / Q000294:innervation; D008642:Mesenteric Veins / Q000294:innervation; D051381:Rats; D017207:Rats, Sprague-Dawley; D017476:Receptors, Neuropeptide Y / Q000037:antagonists & inhibitors / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000502:physiology*; D014661:Vasoconstriction / Q000502:physiology*
C092926:BIBP 3226; D017476:Receptors, Neuropeptide Y; D001120:Arginine