TY - JOUR
T1 - Anti-arrhythmic peptide N-3-(4-hydroxyphenyl)propionyl Pro-Hyp-Gly-Ala-Gly-OH reduces dispersion of action potential duration during ischemia/reperfusion in rabbit hearts.
AU - Kjølbye, Anne Louise
AU - Petersen, Jørgen Søberg
AU - Holstein-Rathlou, N.-H.
N1 - Keywords: Action Potentials; Animals; Anti-Arrhythmia Agents; Electrocardiography; Electrophysiology; Heart; Hemodynamics; Ischemia; Male; Myocardial Contraction; Rabbits; alpha-Defensins
PY - 2002
Y1 - 2002
N2 - During ischemia, cardiac gap junctions close and neighboring cells uncouple. This leads to slow conduction, increased dispersion of APD90 (duration from action potential beginning to 90% of repolarization), nonuniform anisotropy, and unidirectional conduction block, all of which favor the induction of reentry arrhythmias. It has been suggested that anti-arrhythmic peptides increase gap junction conductance during states of reduced coupling. The aim of this study was to test the effect of the anti-arrhythmic peptide N-3-(4-hydroxyphenyl)propionyl Pro-Hyp-Gly-Ala-Gly-OH (HP-5) (10(-10) ) on dispersion of epicardial APD90 during both normokalemic and hypokalemic ischemia/reperfusion in isolated perfused rabbit hearts. HP-5 did not affect average APD90, heart rate, left ventricular contractility (LVP dP/dtmax), or mean coronary flow. HP-5 significantly reduced the epicardial APD dispersion during hypokalemic ischemia (HP-5 treated: 24.1 +/- 3.4 ms, untreated: 33.9 +/- 3.1 ms, p < 0.05 versus untreated) and during normokalemic reperfusion but not during normokalemic ischemia or control conditions. In addition, among untreated hearts subjected to hypokalemic ischemia/reperfusion, seven of 10 developed ventricular fibrillation, whereas only three of nine hearts perfused with HP-5 developed ventricular fibrillation. These results show that HP-5 is able to reduce APD90 dispersion during hypokalemic ischemia in rabbit hearts.
AB - During ischemia, cardiac gap junctions close and neighboring cells uncouple. This leads to slow conduction, increased dispersion of APD90 (duration from action potential beginning to 90% of repolarization), nonuniform anisotropy, and unidirectional conduction block, all of which favor the induction of reentry arrhythmias. It has been suggested that anti-arrhythmic peptides increase gap junction conductance during states of reduced coupling. The aim of this study was to test the effect of the anti-arrhythmic peptide N-3-(4-hydroxyphenyl)propionyl Pro-Hyp-Gly-Ala-Gly-OH (HP-5) (10(-10) ) on dispersion of epicardial APD90 during both normokalemic and hypokalemic ischemia/reperfusion in isolated perfused rabbit hearts. HP-5 did not affect average APD90, heart rate, left ventricular contractility (LVP dP/dtmax), or mean coronary flow. HP-5 significantly reduced the epicardial APD dispersion during hypokalemic ischemia (HP-5 treated: 24.1 +/- 3.4 ms, untreated: 33.9 +/- 3.1 ms, p < 0.05 versus untreated) and during normokalemic reperfusion but not during normokalemic ischemia or control conditions. In addition, among untreated hearts subjected to hypokalemic ischemia/reperfusion, seven of 10 developed ventricular fibrillation, whereas only three of nine hearts perfused with HP-5 developed ventricular fibrillation. These results show that HP-5 is able to reduce APD90 dispersion during hypokalemic ischemia in rabbit hearts.
M3 - Journal article
C2 - 12409986
SN - 0160-2446
VL - 40
SP - 770
EP - 779
JO - Journal of Cardiovascular Pharmacology
JF - Journal of Cardiovascular Pharmacology
IS - 5
ER -