Effects of tetrandrine and fructose-1,6-diphosphate on the elevated intrasynaptosomal [Ca~2+]_i induced by excitatory amino acids / 中国病理生理杂志

ABSTRACT

AIM: To study the effects of tetrandrine(Tet) and fructose-1,6-diphosphate(FDP) on the elevated intrasynaptosomal [Ca 2+ ] i induced by excitatory amino acids (EAA). METHODS: A rapid method for preparing synaptosomes was used, and intrasynaptosomal free calcium ([Ca 2+ ] i) was measured by using the fluorescent indicator quin-2. RESULTS: L-glutamate (Glu, 100 ?mol/L), aspartate (Asp, 100 ?mol?L -1 ), N-methy1-D-aspartate (100 ?mol/L) and Glu (50 ?mol/L) plus Asp (50 ?mol/L) all elevated intrasynaptosomal [Ca 2+ ] i in a dose-dependent manner. Pretreatment with Tet (10,30,60 ?mol/L) , FDP (15, 30, 75, 150 ?mol/L), MK-801 (10, 20 ?mol/L) and Tet (15, 30 ?mol/L) plus FDP(15, 30 ?mol/L) all attenuated the increase in intrasynaptosomal [Ca 2+ ] i induced by EAAs mentioned as above in a dose-dependent manner, and the effect of Tet plus FDP was most significant. CONCLUSION: Both Tet and FDP inhibited a rise in intrasynaptosomal [Ca 2+ ] i induced by EAAs, which may be one of mechanisms that Tet and FDP pretect cerebral tissues against ischemia injury.