Free amino acids in the cytosol of human atrium and ventricle of the heart, as analyzed by gas-liquid chromatography.

Size and composition of the amino acid pool in the cell cytosol of atrial and ventricular heart muscle of 6-8 week old human embryos was evaluated by gas-liquid chromatography. It was found that the free amino acid pool in the ventricular heart muscle is about 50% higher than in the atrium. Arginine constituted the most abundant amino acid in the ventricular and atrial heart muscle as well. Glutamic acid and alanine were the next most common amino acids and represented 10-18% and 7-10% of the amino acid pools, respectively. After appropriate biotransformation, these amino acids may not only be important substrates for the energy cycles of the heart, but may also play a critical role as stimulators of mitosis and regulators of the synthesis of nucleic acids and proteins.