L(+)-2-Amino-4-Phosphonobutyrate Inhibits the Release of Both Glutamate and Dynorphin from Guinea Pig but not Rat Hippocampal Mossy Fiber Synaptosomes.

摘要

The Potassium(+)-evoked release of dynorphin A(1-8)-like immunoreactivity from guinea pig hippocampal mossy fiber synaptosomes was inhibited 53% by L(+)-2-amino-4-phosphonobutyrate(L(+)APB, 300 micromoles), a gultamate analogue. Equimolar L(+)APB also inhibited the Calcium(2+)-dependent component of endogenous L-glutamate release from these mossy fiber synaptosomes by 40%. The L(+)-evoked release of both glutamate and dynorphin A(1-8) from rat hippocampal mossy fiber synaptosomes were unaffected by K(+)APB. It is proposed that L(+)APB selectively suppresses the excitatory mossy fiber synaptic input by inhibiting the Ca(2+)-dependent release of glutamate and dynorphin A(1-8) from guinea pig but not rat hippocampal mossy fiber terminals. Reprints. (AW)