INHIBITION OF Na+/Ca2+ EXCHANGE BY TETRAPEPTIDE FMRFa IN INTACT RAT VENTRICULAR MYOCYTES
- Author:
- No author available
- Journal Title:
- ACTA PHARMACEUTICA SINICA
- Issue:
- 1
- DOI:
- 10.3321/j.issn:0513-4870.2001.01.003
- Key Word:
- FMRFa;Na+/Ca+交换;膜片钳
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.
- [1]Stengl M,Flameng W,Mubagwa K.Extracellular divalent cations block a cation non-selective conductance unrelated to calcium channels in rat cardiac muscle.[J].1997,502(Pt.2).
- [2]T R, Kleyman,E J, Cragoe.Amiloride and its analogs as tools in the study of ion transport.[J].1988,105(1).
- [3]Daniel Khananshvili,Yosef Sarne.The effect of opiate agonists and antagonists on Na+-Ca2+ exchange in cardiac sarcolemma vesicles[J].1992,51(4).
- [4]Khananshvili D,Baazov D,Weil Maslansky E,etc.Positively charged cyclic hexapeptides, novel blockers for the cardiac sarcolemma Na(+)-Ca2+ exchanger.[J].1995,270(27).
- [5]D, Khananshvili,D C, Price,M J, Greenberg,etc.Phe-Met-Arg-Phe-NH2 (FMRFa)-related peptides inhibit Na(+)-Ca2+ exchange in cardiac sarcolemma vesicles.[J].1993,268(1).
- [6]D. A. NICOLL,K. D. PHILIPSON.Molecular Studies of the Cardiac Sarcolemmal Sodium-Calcium Exchanger[J].1991,639(1).
- [7]T K, Chin,K W, Spitzer,K D, Philipson,etc.The effect of exchanger inhibitory peptide (XIP) on sodium-calcium exchange current in guinea pig ventricular cells.[J].1993,72(3).