Cardiac fatty acid metabolism is preserved in the compensated hypertrophic rat heart.
Cardiac hypertrophy and failure are associated with alterations in cardiac substrate metabolism. It remains to be established, however, whether genomically driven changes in cardiac glucose and fatty acid (FA) metabolism represent a key event of the hypertrophic remodeling process. Accordingly, we investigated metabolic gene expression and substrate metabolism during compensatory hypertrophy, in relation to other cardiac remodeling processes. Thereto, cardiac hypertrophy was induced in rats by supra-renal aortic constriction to various degrees, resulting in increased heart/body weight ratios of 22% (Aob-1), 24% (Aob-2) and 32% (Aob-3) (p < 0.005) after 4 weeks. The unaltered ejection fraction in all groups indicated that the hypertrophy was still compensatory in nature. beta-Myosin Heavy Chain protein and ANF mRNA levels were increased in all groups. Only in Aob-3 rats were SERCA2a mRNA levels markedly reduced. In this group, glycolytic capacity was modestly elevated (+ 25%; p < 0.01). Notwithstanding these phenotypical changes, the expression of genes involved in FA metabolism and FA oxidation rate in cardiac homogenates was completely preserved, irrespective of the degree of hypertrophy. These findings indicate that cardiac FA oxidative capacity is preserved during compensatory hypertrophy, and that a decline in metabolic gene expression does not represent a hallmark of the development of hypertrophy.
Degens
Hans
H
Dep. of Physiology, Cardiovascular Research Institute Maastricht (CARIM) Maastricht University, 616, 6200 MD Maastricht, the Netherlands.
de Brouwer
Kristel F J
KF
Gilde
Andries J
AJ
Lindhout
Martijn
M
Willemsen
Peter H M
PH
Janssen
Ben J
BJ
van der Vusse
Ger J
GJ
van Bilsen
Marc
M
D000818:Animals; D001012:Aorta, Abdominal / Q000601:surgery; D005227:Fatty Acids / Q000378:metabolism*; D020869:Gene Expression Profiling; D006321:Heart / Q000503:physiopathology; D017379:Hypertrophy, Left Ventricular / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D009206:Myocardium / Q000201:enzymology / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D051381:Rats; D017208:Rats, Wistar
D005227:Fatty Acids