Regulation of calcium uptake in synaptosomes from rat brain by DL-2-amino-5-phosphonovaleric acid.

DL-2-Amino-5-phosphonovaleric acid stimulated calcium influx into synaptosomes isolated from rat brain. The increase in Ca2+ permeability of the synaptosomal membranes induced by this amino acid is not markedly dependent on the membrane potential or Na+ concentration. It is postulated that 2-amino-5-phosphonovaleric acid is an agonist for a receptor(s) which regulates intraneuronal free calcium concentrations by modulating a selective calcium channel. The observed stimulation of calcium uptake may provide an assay system for purification of the endogenous ligand for this receptor and for characterization of its physiological role in neuronal function.