Separate modulation of neuropeptide Y1 receptor on purinergic and on adrenergic neuroeffector transmission in canine splenic artery.
Our previous study demonstrated that the vasoconstrictor responses to trains of up to 10 pulses at 1 Hz of stimulation appeared to be purinergic monophasic, whereas a longer train of 30 pulses induced a biphasic vasoconstriction consisting of an initial, transient purinergic constriction followed by a prolonged adrenergic response. Neuropeptide Y (NPY) at doses of 0.01 and 0.1 microM produced a dose-dependent inhibition on the monophasic and biphasic vasoconstrictor responses to nerve stimulation. The treatment with Leu31 Pro34 neuropeptide Y (LP-NPY) (0.03 microM) did not affect the monophasic responses to short pulse trains of stimulation. However, LP-NPY markedly potentiated the second phase response to 30 pulse trains of stimulation, although it did not modify the first one. The LP-NPY-induced potentiation was abolished by BIBP 3226 (1 microM), a selective NPY Y1 receptor antagonist. The results indicate that the activation of NPY Y1 receptors may enhance the prolonged adrenergic vasoconstriction but not the transient purinergic response in the canine splenic artery.
Yang
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Department of Pharmacology, Shinshu University School of Medicine, Matsumoto, Japan.
Chiba
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D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004285:Dogs; D004558:Electric Stimulation; D005260:Female; D008297:Male; D009451:Neuroeffector Junction / Q000187:drug effects / Q000502:physiology*; D009478:Neuropeptide Y / Q000494:pharmacology / Q000502:physiology; D011941:Receptors, Adrenergic / Q000502:physiology*; D017476:Receptors, Neuropeptide Y / Q000819:agonists / Q000037:antagonists & inhibitors / Q000502:physiology*; D011983:Receptors, Purinergic / Q000502:physiology*; D013157:Splenic Artery / Q000187:drug effects / Q000294:innervation*; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology
D014151:Anti-Anxiety Agents; C092926:BIBP 3226; D009478:Neuropeptide Y; D011941:Receptors, Adrenergic; D017476:Receptors, Neuropeptide Y; D011983:Receptors, Purinergic; C097212:neuropeptide Y-Y1 receptor; D001120:Arginine