Manipulation of chloride flux affects histamine-induced contraction in rabbit basilar artery.
Cl(-) efflux induces depolarization and contraction of smooth muscle cells. This study was undertaken to explore the role of Cl(-) flux in histamine-induced contraction in the rabbit basilar artery. Male New Zealand White rabbits (n = 16) weighing 1.8-2.5 kg were euthanized by an overdose of pentobarbital sodium. The basilar arteries were removed for isometric tension recording. Histamine produced a concentration-dependent contraction that was attenuated by the H(1) receptor antagonist chlorpheniramine (10(-8) M) but not by the H(2) receptor antagonist cimetidine (3 x 10(-6) M) in normal Cl(-) Krebs-Henseleit bicarbonate solution (123 mM Cl(-)). The histamine-induced contraction was reduced by the following manipulations: 1) inhibition of Na(+)-K(+)-2Cl(-) cotransporter with bumetanide (3 x 10(-5) and 10(-4) M), 2) bicarbonate-free HEPES solution to disable Cl(-)/HCO exchanger, and 3) blockade of Cl(-) channels with the use of niflumic acid, 5-nitro-2-(3-phenylpropylamino) benzoic acid, and indoleacetic acid 94 R-(+)-methylindazone. In addition, substitution of extracellular Cl(-) (10 mM) with methanesulfonate acid (113 mM) transiently enhanced histamine-induced contraction. Manipulation of Cl(-) flux affects histamine-induced contraction in the rabbit basilar artery.
Dai
Yun
Y
Department of Neurosurgery, University of Mississippi Medical Center, Jackson, Mississippi 39216, USA.
Zhang
John H
JH
D000818:Animals; D001488:Basilar Artery / Q000187:drug effects / Q000502:physiology*; D002034:Bumetanide / Q000494:pharmacology; D002712:Chlorides / Q000494:pharmacology*; D006531:HEPES / Q000494:pharmacology; D006632:Histamine / Q000494:pharmacology*; D066298:In Vitro Techniques; D007537:Isometric Contraction / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008698:Mesylates / Q000494:pharmacology; D008955:Models, Cardiovascular; D011189:Potassium Chloride / Q000494:pharmacology; D011817:Rabbits; D013314:Stress, Mechanical; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*
D002712:Chlorides; D008698:Mesylates; D002034:Bumetanide; C045880:methanesulfonic acid; D011189:Potassium Chloride; D006632:Histamine; D006531:HEPES