Effects of docosahexaenoic and arachidonic acids on contractility in cultured rat cardiomyocytes

Abstract

The twitch stress of cardiac tissue equivalent reconstructed in vitro is markedly lower than that in vivo. We previously found that the contents of polyunsaturated fatty acids, especially docosahexaenoic (DHA) and arachidonic (AA) acids, in cultured rat cardiomyocytes was lower than those in neonatal myocardium, and that contractile function in cultured cardiomyocytes could be maximized under 20 μM DHA or 50 μM AA supplementation (n=4-10). In the present study, we evaluated contractile function of rat cardiomyocytes under simultaneous supplementation of 5-20 μM DHA and 5-40 μM AA. Four days after the onset of 10 μM DHA + 10 μM AA supplementation, the contractile fraction was significantly higher (P<0.05) than that in cells without supplementation (n=8) while no significant difference was observed in the beat rate. These results suggest that simultaneous supplementation of 10 μM DHA and 10 μM AA can elevate contractile function of cardiomyocytes.