Interaction between neuropeptide Y Y1 receptors and alpha1B-adrenoceptors in the neurovascular junction of canine splenic arteries.
Previous study has demonstrated that periarterial electrical nerve stimulation (30-s trains of pulses at a frequency of 1 or 4 Hz) induces a double-peaked vasoconstriction consisting of an initial transient, predominantly P2X-receptor-mediated constriction followed by a prolonged, mainly alpha(1)-adrenoceptor-mediated response in the isolated canine splenic artery. Treatment with 8-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-8-azaspiro[4.5]decane-7,9-dione (BMY 7378, 0.1 micromol/l), a selective alpha(1D)-adrenoceptor antagonist, produced a slight but significant inhibition of the second peaked responses. A marked inhibition of second peaked responses was obtained by exposure of the tissues to chloroethylclonidine (60 micromol/l), an alpha(1B)- and alpha(1D)-adrenoeptor antagonist. Neither BMY 7378 nor chloroethylclonidine affected the first peaked vasoconstrictor responses. [Leu(31),Pro(34)]Neuropeptide Y (10-30 nmol/l), a selective neuropeptide Y Y(1) receptor agonist, enhanced the second peaked responses in the presence of BMY 7378 but failed to enhance the responses in the presence of chloroethylclonidine. The results indicate that the postjunctional alpha(1B)-adrenoceptor subtype is likely coupled to neuropeptide Y Y(1) receptors responsible for the cooperation of the sympathetic adrenergic and neuropeptide Yergic transmission in the canine splenic artery.
Yang
Xiao-Ping
XP
Department of Pharmacology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan.
Chiba
Shigetoshi
S
D058668:Adrenergic alpha-1 Receptor Antagonists; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D003000:Clonidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004285:Dogs; D004558:Electric Stimulation; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009469:Neuromuscular Junction / Q000187:drug effects / Q000502:physiology*; D009478:Neuropeptide Y / Q000031:analogs & derivatives* / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D011485:Protein Binding; D020239:Receptor Cross-Talk / Q000502:physiology; D018340:Receptors, Adrenergic, alpha-1 / Q000378:metabolism*; D017476:Receptors, Neuropeptide Y / Q000819:agonists / Q000378:metabolism*; D013157:Splenic Artery / Q000187:drug effects / Q000294:innervation / Q000502:physiology*; D014661:Vasoconstriction / Q000187:drug effects
D058668:Adrenergic alpha-1 Receptor Antagonists; D000317:Adrenergic alpha-Antagonists; D009478:Neuropeptide Y; D010879:Piperazines; D018340:Receptors, Adrenergic, alpha-1; D017476:Receptors, Neuropeptide Y; C097212:neuropeptide Y-Y1 receptor; C062259:neuropeptide Y, Leu(31)-Pro(34)-; C051731:chlorethylclonidine; C053428:BMY 7378; D003000:Clonidine