Uptake of D-serine by synaptosomal P2 fraction isolated from rat brain

We have demonstrated that the crude synaptosome P2 fraction prepared from the rat brain is able to accumulate [(3)H]D-serine in a saturable, temperature-dependent and partially sodium- and potassium-dependent manner with an affinity of a hundred micromolar range. The inhibition profile of D-serine accumulation by various amino acids is different from those of uptake systems reported for glycine and other amino acids. The present data suggest that the endogenous D-serine may be taken up mainly through a carrier-mediated transport system to regulate its extracellular concentration in the mammalian brain.