Palmitate oxidation by beating heart cells in culture

Palmitic acid oxidation has been studied in cultures of beating heart cells. The data reported suggest: 1. The main source of fatty acids for oxidation in cell cultures is provided by lypolysis of preexisting intracellular fatty acids. Most fatty acids that have just entered the cell are not oxidized immediately. Thus, aged heart cells in culture seem to retain their ability to utilize fatty acids as their main energy source. 2. In cultured heart cells, the amount of CO2 obtained from the carboxyl group was much higher than that obtained from the methyl group. On the other hand, beta-hydroxybutrate has been shown to be formed mainly from the methyl group. This may indicate that beta-oxidation terminates at the beta-hydroxybutyrate stage because of premature dissociation of this last intermediate from the enzyme complex.