title: Interference of pentobarbital and thiopental with the vascular contraction and noradrenaline release in human cerebral arteries.
abstract: Thiopental and pentobarbital induced dose-dependent vasodilations in human cerebral arteries previously contracted with noradrenaline (NA), serotonin (5-HT) and KCl. Preincubation with both barbiturates decreased the contractions evoked by the three agents. Pentobarbital and thiopental reduced the Ca2+-induced contractile effects in K+-depolarized arteries and 5-HT-Ca2+ and NA-Ca2+ contractions dose-dependently. The tritium release evoked by K+ from these vessels prelabelled with [3H]NA was significantly reduced by both barbiturates at 10(-3) M and by Ca2+ removal. These results indicate that pentobarbital and thiopental essentially produce a similar interference with Ca2+ influx inhibiting the contractile responses induced by the three vasoactive agents and the exocytotic NA release evoked by K+.
mesh_terms: D002536:Cerebral Arteries / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D009638:Norepinephrine / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010424:Pentobarbital / Q000494:pharmacology*; D011188:Potassium / Q000037:antagonists & inhibitors; D012702:Serotonin Antagonists; D013874:Thiopental / Q000494:pharmacology*; D014661:Vasoconstriction / Q000187:drug effects*
chemical_list: D012702:Serotonin Antagonists; D010424:Pentobarbital; D013874:Thiopental; D011188:Potassium; D009638:Norepinephrine