Taurine relaxes human radial artery through potassium channel opening action
Taurine relaxes human radial artery through potassium channel opening action
- 대한생리학회-대한약리학회
- The Korean Journal of Physiology & Pharmacology
- 제21권 제6호
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2017.01617 - 623 (7 pages)
- 2
The vascular actions and mechanisms of taurine were investigated in the isolated human radial artery (RA). RA rings were suspended in isolated organ baths and tension was recorded isometrically. First, a precontraction was achieved by adding potassium chloride (KCl, 45 mM) or serotonin (5-hydroxytryptamine, 5-HT, 30 µM) to organ baths. When the precontractions were stable, taurine (20, 40, 80 mM) was added cumulatively. Antagonistic effect of taurine on calcium chloride (10 µM to 10 mM) -induced contractions was investigated. Taurine-induced relaxations were also tested in the presence of the K<sup>+</sup> channel inhibitors tetraethylammonium (1 mM), glibenclamide (10 µM) and 4-aminopyridine (1 mM). Taurine did not affect the basal tone but inhibited the contraction induced by 5-HT and KCl. Calcium chloride–induced contractions were significantly inhibited in the presence of taurine (20, 40, 80 mM) (p<0.05). The relaxation to taurine was inhibited by tetraethylammonium (p<0.05). However, glibenclamide and 4-aminopyridine did not affect taurine -induced relaxations. Present experiments show that taurine inhibits 5-HT and KCl -induced contractions in RA, and suggest that large conductance Ca<sup>2+</sup>-activated K<sup>+</sup> channels may be involved in taurine –induced relaxation of RA.
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