Preconditioning limits myocardial infarct size in hypercholesterolemic rabbits.
BACKGROUND
Hypercholesterolemia predisposes to coronary artery disease and causes endothelial dysfunction; some reports suggest that endothelial derived substances are involved in ischemic preconditioning.


OBJECTIVE
Our aim was to examine the possibility that preconditioning maybe attenuated in a clinically relevant animal model of hypercholesterolemia with atherosclerosis.


METHODS
Male rabbits were fed with cholesterol enriched diet and then divided into two groups (A and B) without and with preconditioning, respectively. A second series of rabbits fed a normal diet were similarly divided into two groups (C and D) without and with preconditioning, respectively. All the animals were subjected to 30 min ischemia and 180 min reperfusion. Blood samples were collected for cholesterol assessment; arterial and heart samples were harvested at the end for histopathological examination. Infarct (I) and risk areas (R) were delineated with Zn-Cd particles and TTC staining.


RESULTS
Cholesterol in groups A and B was 58.3+/-8.7 mg% at baseline and 1402+/-125 mg% at 8 weeks (P<0.0001) and in groups C and D 57.5+/-5.8 mg% before the surgical procedure. I/R% was 39. 3+/-6.3% in group A, 16.7+/-3.9% in B (P<0.01), 41.4+/-7.5% in C and 10.8+/-3.3% in D (P<0.01).


CONCLUSIONS
We conclude that preconditioning is unlikely to be attenuated by hypercholesterolemia.
Kremastinos
D T
DT
Second Department of Cardiology, Onassis Cardiac Surgery Center, 356 Sygrou Avenue, 17674, Athens, Greece. elbee@ath.forthnet.gr
Bofilis
E
E
Karavolias
G K
GK
Papalois
A
A
Kaklamanis
L
L
Iliodromitis
E K
EK
D000818:Animals; D001011:Aorta / Q000473:pathology; D001161:Arteriosclerosis / Q000473:pathology; D003331:Coronary Vessels / Q000473:pathology; D006937:Hypercholesterolemia / Q000150:complications*; D019157:Ischemic Preconditioning, Myocardial; D008297:Male; D009203:Myocardial Infarction / Q000150:complications / Q000473:pathology*; D009206:Myocardium / Q000473:pathology; D011817:Rabbits