Effects of neuropeptide Y and agonists selective for neuropeptide Y receptor sub-types on arterioles of the guinea-pig small intestine and the rat brain.
1. The actions of neuropeptide Y (NPY) and agonists selective for NPY receptor subtypes were examined on arterioles from the guinea-pig small intestine and the rat pia in order to characterize the receptors mediating the vasoconstrictor and potentiating effects of NPY. 2. A method was developed for measuring the potentiating effects of NPY in situations where it was not possible to obtain a full concentration-response relationship for the vasoconstrictor. NPY, 50 nM, had a greater potentiating effect on the guinea-pig intestinal arterioles than those from the rat pia. 3. NPY and the Y1-selective agonist, NPY[Leu31,Pro34], potentiated the constrictor responses to U46619 in both arterioles and responses to noradrenaline in the guinea-pig arterioles. There was marked desensitization of the potentiating effect, and cross-desensitization between NPY and NPY[Leu31,Pro34]. Both NPY and NPY[Leu31,Pro34] caused constriction of the rat pial arterioles but not of those from the guinea-pig intestine. 4. The Y2-selective agonist PYY(13-36) caused no potentiation or vasoconstriction and did not affect the potentiation by NPY or NPY[Leu31,Pro34]. 5. The potentiating and vasoconstrictor effects of NPY on these arterioles were mediated by Y1 receptors.
Xia
J
J
Department of Physiology, Monash University, Clayton, Victoria, Australia.
Neild
T O
TO
Kotecha
N
N
D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D000818:Animals; D001160:Arterioles / Q000187:drug effects; D002560:Cerebrovascular Circulation / Q000187:drug effects; D004357:Drug Synergism; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007421:Intestine, Small / Q000187:drug effects; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009478:Neuropeptide Y / Q000031:analogs & derivatives / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology; D019894:Peptide YY; D010455:Peptides; D011450:Prostaglandin Endoperoxides, Synthetic / Q000494:pharmacology; D051381:Rats; D017476:Receptors, Neuropeptide Y / Q000187:drug effects*; D014661:Vasoconstriction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology
D009478:Neuropeptide Y; D010446:Peptide Fragments; D010455:Peptides; D011450:Prostaglandin Endoperoxides, Synthetic; D017476:Receptors, Neuropeptide Y; D014662:Vasoconstrictor Agents; C078948:peptide YY (13-36); D019894:Peptide YY; C062259:neuropeptide Y, Leu(31)-Pro(34)-; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid