Experimental hyperlipidaemia does not prevent preconditioning and it reduces ischemia-induced apoptosis.
BACKGROUND
Although ischemic preconditioning (PC) is known to confer cardioprotection in healthy subjects, it is unclear whether this phenomenon exists in the presence of hyperlipidaemia. The goal of this study was to determine whether the cardioprotective effect of PC is affected by hyperlipidaemia in a guinea pig model.


METHODS
We investigated the influence of preconditioning in normo- and hyperlipidaemic animals on papillary muscle contractility and myocardial damage as expressed by the percentage of apoptotic cells. Guinea pigs were fed a normal diet or a hyperlipidaemic diet for 5 weeks. Experiments were performed on papillary muscles subjected to experimental ischemia-reperfusion with or without prior PC.


RESULTS
The dietary treatment resulted in significant changes in lipid parameters, which had not affected the functionality of the right ventricle papillary muscle, both at basal conditions and in response to ischemia-reperfusion injury. However, it was found that the hyperlipidaemic diet had an effect on ischemia-induced apoptosis. Papillary muscles of hyperlipidaemic animals with higher HDL plasma concentrations were less susceptible to ischemia-reperfusion injury.


CONCLUSIONS
This study demonstrates that hyperlipidaemia does not alter the benefits of ischemic preconditioning such as a reduction of apoptosis and preservation of myocardial contractility. Additionally, it has been shown that plasma HDL may protect cardiomyocytes against ischemia-induced apoptosis.
Dworakowski
Rafal
R
I Department of Cardiology, Medical University of Gdańsk, Poland. rdw1@amg.gda.pl
Dworakowska
Dorota
D
Kocic
Ivan
I
Wirth
Tomas
T
Gruchała
Marcin
M
Kamiński
Maciej
M
Ray
Robin
R
Petrusewicz
Jacek
J
Yla-Herttuala
Seppo
S
Rynkiewicz
Andrzej
A
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002784:Cholesterol / Q000096:biosynthesis / Q000097:blood; D008076:Cholesterol, HDL / Q000096:biosynthesis / Q000097:blood; D008078:Cholesterol, LDL / Q000096:biosynthesis / Q000097:blood; D004195:Disease Models, Animal; D006168:Guinea Pigs; D006949:Hyperlipidemias / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology*; D019157:Ischemic Preconditioning, Myocardial / Q000379:methods*; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology; D017202:Myocardial Ischemia / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology*; D010210:Papillary Muscles / Q000378:metabolism / Q000473:pathology / Q000502:physiology; D014280:Triglycerides / Q000096:biosynthesis / Q000097:blood
D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D014280:Triglycerides; D002784:Cholesterol