Long-chain fatty acids modify hypertrophic responses of cultured primary neonatal cardiomyocytes.
In vivo, the normal heart obtains at least 60% of its energy from lipids and the remainder from glucose. Several lines of evidence indicate that an increase in the utilization of glucose [at the expense of fatty acids (FA)] may play a role in the genesis of hypertrophy. Primary cultures of neonatal cardiomyocytes have been used extensively to study the phenotype of these cells as well as their responses to hormonal hypertrophic agents. Unfortunately, such cultures are most typically cultured in glucose-rich FA-free media, and thus might be hypertrophied to start with. We therefore tested the effects of FA-albumin complexes on three different surrogate end points of hypertrophy of cardiomyocytes. Oleate-albumin complexes decreased the baseline values of all three variables, and increased the relative response of these variables to administration of norepinephrine. Oleate:palmitate-albumin complexes also affected all three variables and their responses to norepinephrine, but the effects differed somewhat from that of oleate-albumin complexes. Our results suggest that addition of long-chain FA, by providing conditions that more closely resemble physiological situations, may optimize the expression of hypertrophic responses in such cells. However, the differences between the effects of oleate and oleate:palmitate also suggest that the precise composition of FA may affect the phenotype of cardiomyocytes and how these cells respond to hypertrophic agents.
Zahabi
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A
Experimental Cardiovascular Biology Research Unit and CIHR Multidisciplinary Research Group on Hypertension, Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada H2W 1R7.
Deschepper
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CF
D000818:Animals; D000831:Animals, Newborn; D009320:Atrial Natriuretic Factor / Q000378:metabolism; D006332:Cardiomegaly / Q000378:metabolism / Q000473:pathology*; D048429:Cell Size / Q000187:drug effects; D002478:Cells, Cultured; D003470:Culture Media; D005227:Fatty Acids / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects*; D009206:Myocardium / Q000378:metabolism / Q000473:pathology*; D009638:Norepinephrine / Q000494:pharmacology; D019301:Oleic Acid / Q000494:pharmacology; D019308:Palmitic Acid / Q000494:pharmacology; D014176:Protein Biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012710:Serum Albumin, Bovine / Q000494:pharmacology
D003470:Culture Media; D005227:Fatty Acids; D012710:Serum Albumin, Bovine; D019301:Oleic Acid; D019308:Palmitic Acid; D009320:Atrial Natriuretic Factor; D009638:Norepinephrine