Effects of L-765,314, a selective and potent alpha 1B-adrenoceptor antagonist, on periarterial nerve electrical stimulation-induced double-peaked constrictor responses in isolated dog splenic arteries.
The periarterial nerve electrical stimulation (PNS) at a frequency of 1 or 4 Hz (30-s trains of pulses) readily caused a double peaked vasoconstriction in the canine splenic artery. The treatment with 1 microM L-765,314, a selective and potent alpha1B-adrenoceptor antagonist, markedly inhibited the second peaked constriction, whereas it did not modify the vasoconstrictor responses to exogenous noradrenaline (0.03-1 nmol) and A61603 (1-30 pmol), a selective alpha1A-agonist. A large dose of 10 microM L-765,314 significantly blocked exogenous noradrenaline- and A61603-induced responses. It is concluded that PNS-induced responses are mediated via the postjunctional alpha1B-adrenoceptor subtype.
Yang
Xiao-Ping
XP
Department of Pharmacology, Shinshu University School of Medicine, Matsumoto, Japan.
Chiba
Shigetoshi
S
D058668:Adrenergic alpha-1 Receptor Antagonists; D000818:Animals; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009412:Nerve Fibers / Q000187:drug effects* / Q000502:physiology; D011224:Prazosin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D018340:Receptors, Adrenergic, alpha-1 / Q000502:physiology; D013157:Splenic Artery / Q000187:drug effects* / Q000502:physiology; D014661:Vasoconstriction / Q000187:drug effects* / Q000502:physiology
D058668:Adrenergic alpha-1 Receptor Antagonists; C111640:L 765314; D018340:Receptors, Adrenergic, alpha-1; D011224:Prazosin