Inotropic and chronotropic effects of ischemic postconditioning on the model of isolated heart.
The effects of global ischemia (45 min) and reperfusion (30 min) on left-ventricular developed pressure (LVDP), HR, and end-diastolic pressure were studied on isolated perfused rat heart. The following postconditioning protocols were used: 1) 3 cycles of reperfusion (10 sec) and ischemia (10 sec), total cycle duration 20 sec; 2) 6 cycles reperfusion of reperfusion (10 sec) and ischemia (10 sec), total cycle duration 20 sec; 3) 3 cycles of reperfusion (20 sec) and ischemia (20 sec), total cycle duration 40 sec; 4) 6 cycles of reperfusion (20 sec) and ischemia (20 sec), total cycle duration 40 sec; 5) 3 cycles of reperfusion (30 sec) and ischemia (30 sec), total cycle duration 60 sec. The use of several cycles of a total duration of 20 sec had no effect on LVDP, but reduced EDP throughout the reperfusion period. Postconditioning protocol consisting of three 40-sec cycles promoted LVDP recovery during the reperfusion, but had no effect on EDP and decelerated HP normalization. Six 40-sec cycles had no effect on LVDP and EDP, but impeded HR recovery during the reperfusion period. Postconditioning protocol consisting of three 60-sec cycles promoted LVDP increase during the reperfusion and reduced contracture, but these transient effects were accompanied by decelerated HP normalization.
Institute of Cardiology, Siberian Division of the Russian Academy of Medical Sciences, Tomsk, Russia. maslov@cardio.tsu.ru
L N
LN
Maslov
A S
AS
Gorbunov
T V
TV
Lasukova
Yu B
YB
Lishmanov
D000818:Animals; D001794:Blood Pressure; D006321:Heart / Q000503:physiopathology*; D006339:Heart Rate; D007511:Ischemia / Q000503:physiopathology*; D057775:Ischemic Postconditioning / Q000379:methods*; D008297:Male; D009200:Myocardial Contraction; D015428:Myocardial Reperfusion Injury / Q000503:physiopathology*; D009924:Organ Culture Techniques; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D017725:Ventricular Pressure