Amino acids modulate calcium permeability of the plasma membrane of human neuroblastoma cells.
Four different amino acids (kainate, N-methyl-D-aspartate, L-cysteine sulfinate and D,L-2-amino-5-phosphonovalerate) have been observed to stimulate uptake of 45Ca2+ into human neuroblastoma cells. This stimulation of uptake is specific and many amino acids which are structural analogs of the above compounds are without activity. The calcium movement is not inhibited by compounds which block voltage-dependent calcium channels. Biological specificity is observed in which some cell lines respond to the amino acids and others do not. It is concluded that these amino acids are acting on a class of receptors whose physiological role is modulation of neuronal metabolism by modulating the calcium permeability of the plasma membrane. The amino acids can substitute for the, as yet, unidentified natural agonists, albeit with low affinity.更多