Sl. Hale et Ra. Kloner, Ischemic preconditioning and myocardial hypothermia in rabbits with prolonged coronary artery occlusion, AM J P-HEAR, 45(6), 1999, pp. H2029-H2034
Citations number
22
Categorie Soggetti
Cardiovascular & Hematology Research
Journal title
AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY
Ischemic preconditioning and myocardial hypothermia in rabbits with prolong
ed coronary artery occlusion. Am. J. Physiol. 276 (Heart Circ. Physiol. 45)
: H2029-H2034, 1999.-This study tests whether combining regional hypothermi
a and ischemic preconditioning (IP) provides greater myocardial protection
during prolonged coronary artery occlusion (CAO) than either intervention a
lone, and whether increasing the duration of TP from 5 to 7 min extends the
window of protection to include a 2-h CAO. Anesthetized rabbits were rando
mized to four groups (n = 8 rabbits/group): control (C), hypothermia alone
(H), IP alone for two 7-min episodes (IP7), and IP plus hypothermia (H + IP
7). To compare differences in IP for 5 versus 7 min, additional rabbits (n
= 6) received one 5-min episode of ischemia (IP5). All rabbits got 2 h of C
AO and 3 h of reperfusion. Tn comparison with the infarct size in the contr
ol group (72 +/- 4% of the risk zone), infarct size was significantly reduc
ed in H (50 +/- 7%), IP7 (49 +/- 5%), and H + IP7 (42 +/- 6%) (all P < 0.05
vs. control group). IP5 failed to confer protection (67 +/- 5% of the risk
zone). Therefore, TP can protect against a 2-h CAO if the TP regimen is in
creased from 5 to 7 min. The combination therapy significantly improved reg
ional myocardial blood flow in the previously ischemic region to a greater
extent than either treatment alone.