Human promyelocytic
leukemia (HL-60), human
squamous carcinoma (HSC-2, HSC-4, NA) and rat
pheochromocytoma (PC-12) cell lines consumed nonpolar (Leu,
Ile, Val, Cys,
Met, Phe), neutral polar (Gln, Ser, Thr, Tyr) and basic polar
amino acids (
Arg, Lys, His), whereas they produced nonpolar (
Gly, Pro, Ala) and acidic polar
amino acids (Glu). The consumption rate of Ser and Arg by HL-60 cells was significantly higher than that of other cell lines. During apoptosis of HL-60 cells induced by either
sodium ascorbate,
sodium 5,6-benzylidene-L-ascorbate (SBA) or
dopamine, the consumption of nonpolar and polar
amino acids (neutral or acidic) generally declined, except for Cys, Met and Arg, whereas the production of Gly and Glu was slightly increased. Since the intracellular concentration of cGMP was not significantly changed before and after ascorbate treatment,
nitric oxide might not be involved in the ascorbate-induced apoptosis. The present data demonstrates that consumption rate of nonpolar and polar
amino acid, whether neutral, acidic or basic, was reduced almost evenly during the apoptosis induction. This suggests that apoptosis-associated changes in the
amino acid utilization might not be significantly affected by
ATP depletion, which might be caused by
mitochondrial dysfunction.