Magnesium lithospermate B dilates mesenteric arteries by activating BKCa currents and contracts arteries by inhibiting KV currents
| Autor: | Xue-qing Chen, Hai-fei Zhang, Guo-yuan Hu, Yiping Wang |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Male
Patch-Clamp Techniques Potassium Channels Vasodilation In Vitro Techniques Pharmacology Nitric Oxide Potassium Chloride Rats Sprague-Dawley Norepinephrine chemistry.chemical_compound Potassium Channel Blockers medicine Animals Myocyte Pharmacology (medical) Large-Conductance Calcium-Activated Potassium Channels Patch clamp Large-Conductance Calcium-Activated Potassium Channel alpha Subunits Mesenteric arteries Tetraethylammonium Chemistry General Medicine Potassium channel Mesenteric Arteries Rats NG-Nitroarginine Methyl Ester medicine.anatomical_structure Vasoconstriction Potassium Original Article Endothelium Vascular medicine.symptom Peptides Drugs Chinese Herbal Artery |
| Zdroj: | Acta Pharmacologica Sinica. 31:665-670 |
| ISSN: | 1745-7254 1671-4083 |
| DOI: | 10.1038/aps.2010.40 |
| Popis: | To examine the involvement of K(+) channels and endothelium in the vascular effects of magnesium lithospermate B (MLB), a hydrophilic active component of Salviae miltiorrhiza Radix.Isolated rat mesenteric artery rings were employed to investigate the effects of MLB on KCl- or norepinephrine-induced contractions. Conventional whole-cell patch-clamp technique was used to study the effects of MLB on K(+) currents in single isolated mesenteric artery myocytes.MLB produced a concentration-dependent relaxation in mesenteric artery rings precontracted by norepinephrine (1 micromol/L) with an EC(50) of 111.3 micromol/L. MLB-induced relaxation was reduced in denuded artery rings with an EC(50) of 224.4 micromol/L. MLB caused contractions in KCl-precontracted artery rings in the presence of N-nitro-L-arginine methyl ester (L-NAME) with a maximal value of 130.3%. The vasodilatory effect of MLB was inhibited by tetraethylammonium (TEA) in both intact and denuded artery rings. In single smooth muscle cells, MLB activated BK(Ca) currents (EC(50) 156.3 micromol/L) but inhibited K(V) currents (IC(50) 26.1 micromol/L) in a voltage- and concentration-dependent manner.MLB dilated arteries by activating BK(Ca) channels in smooth muscle cells and increasing NO release from endothelium, but it also contracted arteries precontracted with KCl in the presence of L-NAME. |
| Databáze: | OpenAIRE |
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