학술논문
Sulfur dioxide relaxes rat aorta by endothelium-dependent and -independent mechanisms
Document Type
Text
Author
Source
Physiological research | 2009 Volume:58 | Number:4
Subject
Language
English
Abstract
Y.-K- Wang.
Obsahuje seznam literatury
This study aimed to investigate the vasoactivity of sulfur dioxide (SO2), a novel gas identified from vascular tissue, in rat thoracic aorta. The thoracic aorta was isolated, cut into rings, and mounted in organ-bath chambers. After equilibrium, the rings were gradually stretched to a resting tension. Isometric tension was recorded under the treatments with vasoconstrictors, SO2 derivatives, and various drugs as pharmacological interventions. In endothelium-intact aortic rings constricted by 1 μM phenylephrine (PE), SO2 derivatives (0.5 – 8 mM) caused a dose-dependent relaxation. Endothelium removal and a NOS inhibitor L-NAME reduced the relaxation to low doses of SO2 derivatives, but not that to relatively high doses (≥ 2 mM). In endothelium-denuded rings, SO2 derivatives attenuat ed vasoconstriction induced by high K+ (60 mM) or CaCl2 (0.01-10 mM). The relaxation to SO2 derivatives in PE-constricted rings without endothelium was significantly inhibited by blockers of ATP-sensitive K+ (KATP) and Ca2+-activated K+ (KCa) channels, but not by those of voltage-dependent K+ channels, Na+-K+-ATPase or Na+-Ca2+ exchanger. SO2 relaxed vessel tone via endothelium-dependent mechanisms associated with NOS activation, and via endothelium-independent mechanisms dependent on the inhibition of voltage-gated Ca2+ channels, and the opening of KATP and KCa channels.
Obsahuje seznam literatury
This study aimed to investigate the vasoactivity of sulfur dioxide (SO2), a novel gas identified from vascular tissue, in rat thoracic aorta. The thoracic aorta was isolated, cut into rings, and mounted in organ-bath chambers. After equilibrium, the rings were gradually stretched to a resting tension. Isometric tension was recorded under the treatments with vasoconstrictors, SO2 derivatives, and various drugs as pharmacological interventions. In endothelium-intact aortic rings constricted by 1 μM phenylephrine (PE), SO2 derivatives (0.5 – 8 mM) caused a dose-dependent relaxation. Endothelium removal and a NOS inhibitor L-NAME reduced the relaxation to low doses of SO2 derivatives, but not that to relatively high doses (≥ 2 mM). In endothelium-denuded rings, SO2 derivatives attenuat ed vasoconstriction induced by high K+ (60 mM) or CaCl2 (0.01-10 mM). The relaxation to SO2 derivatives in PE-constricted rings without endothelium was significantly inhibited by blockers of ATP-sensitive K+ (KATP) and Ca2+-activated K+ (KCa) channels, but not by those of voltage-dependent K+ channels, Na+-K+-ATPase or Na+-Ca2+ exchanger. SO2 relaxed vessel tone via endothelium-dependent mechanisms associated with NOS activation, and via endothelium-independent mechanisms dependent on the inhibition of voltage-gated Ca2+ channels, and the opening of KATP and KCa channels.