Endothelium-independent Vasoconstricting and Vasodilating Actions of Halothane on Rat Mesenteric Resistance Blood Vessels 

Abstract

Halothane has endothelium-independent vasoconstricting and vasodilating actions in isolated mesenteric resistance blood vessels. The vasoconstricting action appears to involve halothane-induced Ca2+ release from caffeine/ryanodine-sensitive intracellular store(s). The vasodilating action in phenylephrine- or KC1-constricted vessels is independent of the Ca(2+)-releasing action and most likely involves an effect(s) on sarcolemmal-dependent Ca2+ signaling (e.g., extracellular Ca2+ influx) and/or Ca2+ activation of contractile proteins. The magnitude of both the vasoconstricting and the vasodilating actions of halothane in these vessels at clinically relevant concentrations suggests these direct actions contribute to the overall cardiovascular effects of halothane in vivo.

Calcium-Independent Phospholipase A2-Derived Arachidonic Acid Is Essential for Endothelium-Dependent Relaxation by Acetylcholine

“…Vessel Preparation.Vessel isolation and cannulation methods were similar to those previously described (Boyle and Maher, 1995). Mesenteric tissue was removed from halothane-anesthetized Sprague-Dawley rats (250 -350g) and the fourth branch of the mesenteric artery (200-to 250-m outer diameter) was dissected at 4°C in a HEPES buffer consisting of 135 mM NaCl, 2.6 mM NaHCO 3 , 0.34 mM Na 2 HPO 4 , 0.44 mM KH 2 PO 4 , 5 mM KCl, 1.4 mM CaCl 2 , 1.17 mM MgSO 4 , 0.025 mM EDTA, 10 mM HEPES, and 5.5 mM glucose (pH 7.35-7.40).…”

General Anesthetics and Vascular Smooth Muscle

“…Some general anesthetics increased basal vascular tone in vitro (halothane, 125,130,218 -220 enflurane, 160,218,220 thiopental, 221,222 propofol, 223,224 morphine 225 ). 130,219,220 However, in conduit arteries, the volatile anesthetic-induced contractions were only partially inhibited by ryanodine. 130,219,220 However, in conduit arteries, the volatile anesthetic-induced contractions were only partially inhibited by ryanodine.…”

Novel arterial pathology in mice and humans hemizygous for elastin.

“…Arteries studied were cannulated and mounted on the pressure myograph (15). The vessel was transilluminated under an inverted microscope connected to a CCD camera, allowing the continuous recording of the outer diameter of the vessel.…”