Low Contents of Polyunsaturated Fatty Acids in Cultured Rat Cardiomyocytes

Reconstructed myocardial tissue still does not have enough contractility. It is well known that fetal and neonatal cardiomyocytes utilize glucose and lipid, respectively, as their energy substrates, and that cultured ones mainly use glucose in spite that their age is comparable to neonate one, probably due to insufficient supply of lipids from culture medium. In the present study, we compared 7 saturated (SFA), 6 monounsaturated (MUFA) and 11 polyunsaturated (PUFA) fatty acid contents in cultured cardiomyocytes (Cul group) with those in fetal (Fet group, approximately 17 d after impregnation) and neonatal (Neo group, 9 d old) rats, where the age of Cul-group cells was set nearly equal to Neo-group one. SFA contents in Cul group were generally lower than those in Fet group, and were close to those in Neo group, except for C12:0 of which content was highest in Neo group. MUFA contents in Cul group were generally lower than those in Fet group but similar to or rather higher than those in Neo group, except for C24:1n-9 of which content was again highest in Neo group. In contrast, most of PUFA contents in Cul group appeared lower than those in both the Fet and Neo groups, and differences in 5 of 10 detected PUFAs were statistically significant between Cul and Neo groups. The results suggest that PUFA contents in cultured cardiomyocytes might be insufficient to exert enough contractile ability. In conclusion, cultured cardiomyocytes may need more lipid, PUFAs in particular.