title: Angiotensin II receptor subtypes involved in the modulation of purinergic and adrenergic vasoconstrictions to periarterial electrical nerve stimulation in the canine splenic artery.
abstract: Previous experiments demonstrated that periarterial electrical nerve stimulation induced a double-peaked vasoconstriction consisting of an initial transient, predominantly P2X-purinoceptor-mediated, constriction followed by a prolonged, mainly alpha1-adrenoceptor-mediated, response in the canine splenic artery. Angiotensin II at a concentration of 0.1 nM did not affect the basal vascular tone and vasoconstrictions to exogenously administered noradrenaline (0.03-3 nmol) and adenosine 5'-triphosphate (0.01-1 micromol), but it markedly potentiated the double-peaked responses to nerve stimulation. The potentiating effect of angiotensin II was inhibited by KRH-594 (10 nM), a selective angiotensin II type 1 receptor antagonist, but was not influenced by PD123319 (0.01-0.1 microM), a selective angiotensin II type 2 receptor antagonist. The results indicate that angiotensin II potentiates sympathetic purinergic and adrenergic vasoconstrictions through the prejunctional angiotensin II type 1 receptor subtype in the canine splenic artery.
authors.affiliation: Department of Pharmacology, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Xiao-Ping
authors.initials: XP
authors.lastname: Yang
authors.forename: Shigetoshi
authors.initials: S
authors.lastname: Chiba
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D004285:Dogs; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D010477:Perfusion; D058913:Purinergic Agonists; D044140:Receptor, Angiotensin, Type 1; D011941:Receptors, Adrenergic / Q000502:physiology; D011945:Receptors, Angiotensin / Q000819:agonists / Q000145:classification / Q000502:physiology*; D011983:Receptors, Purinergic / Q000502:physiology; D013157:Splenic Artery / Q000187:drug effects / Q000502:physiology*; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*
chemical_list: D058913:Purinergic Agonists; D044140:Receptor, Angiotensin, Type 1; D011941:Receptors, Adrenergic; D011945:Receptors, Angiotensin; D011983:Receptors, Purinergic; D000804:Angiotensin II