Effects of amino acids on calcium uptake by glial and neuroblastoma cells

The uptake of [45Ca] has been studied in clonal glial and neuronal cells. It was somewhat more efficient in the neuroblastoma clone M1 compared to glial clones. In all cases [45Ca] uptake was shown to depend on the phosphate concentration in the incubation medium. It was decreased by the ionophore A 23187 at 200 microM concentration in both neuronal and glial clones. The influence of amino acids some of which are putative neurotransmitters was investigated; the interactions between [45Ca] uptake and these amino acids were related to their concentration and the type of cells used (neuronal or glial). L-aspartate and taurine for example had two opposite effects on [45Ca] uptake by the glial clone NN at two different concentrations; they could therefore play a role in the control of calcium level in the synaptic cleft.