INHIBITION OF Na+/Ca2+ EXCHANGE BY TETRAPEPTIDE FMRFa IN INTACT RAT VENTRICULAR MYOCYTES / 药学学报
Acta Pharmaceutica Sinica
; (12): 10-13, 2001.
Article
de Zh
| WPRIM
| ID: wpr-411870
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WPRO
ABSTRACT
AIM To study the effects of Phe-Met-Arg-Phe-NH2 (FMRFa) on Na+/Ca2+ exchange and its specificity for Na+/Ca2+ exchange in rat ventricular myocytes. METHODS Na+/Ca2+ exchange current and other currents of ion channels were measured using whole cell voltage clamp techniques. RESULTS A dose-related inhibition of tetrapeptide FMRFa on Na+/Ca2+ exchange was observed in rat ventricular myocytes. Inward and outward INa+/Ca2+ were inhibited by 60.1% and 56.5%, respectively, at highest concentration (100 μmol*L-1) and its IC50 were 20 μmol*L-1 and 34 μmol*L-1 in inward and outward INa+/Ca2+, respectively. Inward and outward INa+/Ca2+ were inhibited 38.7% and 34.9%, respectively, at FMRFa 5 μmol*L-1. FMRFa 5 μmol*L-1 and 20 μmol*L-1 did not affect L-type calcium current, sodium current, transient outward current and inward rectifier potassium current. CONCLUSION These data indicate that FMRFa is a specific inhibitor of Na+/Ca2+ exchange in intact rat ventricular myocytes.
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WPRIM
langue:
Zh
Texte intégral:
Acta Pharmaceutica Sinica
Année:
2001
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Article