title: Anisodamine at higher concentrations in inhibiting alpha-adrenergic responses in isolated canine blood vessels.
abstract: The present study was designed to examine the effect of higher concentration of anisodamine on alpha-adrenergic responses in isolated canine blood vessels. Up to 10(-3) mol/L, anisodamine did not significantly affect the responses of saphenous vein to alpha 2-adrenergic agonist UK-14, 304. In contrast, anisodamine (10(-5), 10(-4), 10(-3) mol/L) caused the concentration-response curves of femoral artery to norepinephrine (pA2 = 4.81 +/- 0.11) to phenylephrine (pA2 = 4.86 +/- 0.20) shift markedly. However, the antagonism on the alpha 1-adrenergic responses of canine femoral artery to norepinephrine and phenylephrine by higher concentrations of anisodamine produces dose ratios which yield a linear Schild regression with a slope less than unity, indicating an inequilibrium between agonist, antagonist, and receptors. The probable mechanisms involved are discussed.
authors.affiliation: Department of Pathophysiology, Faculty of Basic Medicine, Peking Union Medical College, Beijing.
authors.forename: H Y
authors.initials: HY
authors.lastname: Guo
authors.forename: R R
authors.initials: RR
authors.lastname: Lorenz
authors.forename: P M
authors.initials: PM
authors.lastname: Vanhoutte
mesh_terms: D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D000068438:Brimonidine Tartrate; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005263:Femoral Artery / Q000187:drug effects; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009638:Norepinephrine / Q000037:antagonists & inhibitors; D011810:Quinoxalines / Q000037:antagonists & inhibitors; D012501:Saphenous Vein / Q000187:drug effects; D012991:Solanaceous Alkaloids / Q000494:pharmacology*
chemical_list: D000317:Adrenergic alpha-Antagonists; D011810:Quinoxalines; D012991:Solanaceous Alkaloids; C003922:anisodamine; D000068438:Brimonidine Tartrate; D009638:Norepinephrine