[Effect of 4-aminopyridine on taurine-regulated release of amino acid from rat cortical synaptosomes].

AIM

To elucidate the mechanism of taurine-regulated amino acid release from synaptosomes.

METHODS

Endogenous aspartate, glutamate and GABA release from cortical synaptosomes were measured by high performance liquid chromatography using stepwise elution system, Glutamate release was monitored by continuous fluorometry.

RESULTS

4-Aminopyridine (3.0 x 10(-2) mol.L-1) counteracted the taurine-induced inhibition of glutamate overflow (P < 0.05), while aspartate and GABA release was not affected. Nimodipine (10(-5) mol.L-1) combined with 4-aminopyridine was shown to decrease glutamate release (P < 0.05).

CONCLUSION

Taurine may regulate glutamate release through presynaptic L-type calcium channel and also act on Asp- and GABA-nereve terminal to regulate Asp and GABA release in rat cortex.