ABSTRACT
Objective Effects of aqueous extract from Lishi No.5 formula on concentration of intracellular free-calcium fluorescent intensity in neurons. Methods Hippocampus neurons of 1-day newborn SD rats were cultured with conventional culture technique. The cells cultured for 9-12 days were used for experiment. Intracellular free calcium fluorescent intensity of neurons cultured under different conditions was assayed with confocal microscopic calcium image technique after loading of Fluo-3/AM. Results Free-calcium concentration was enhanced by aqueous extract from Lishi No.5 formula, this concentration was up to 126.35?9.35nmol/L, but the concentration is at normal scope; L-type calcium channel blocker Nifedipine may block the effect of aqueous extract from Lishi No.5 formula enhancing intracellular free-calcium concentration in part, it make intracellular free-calcium concentration down to 90.75?10.15nmol/L, but Nifedipine itself also decreased markedly free-calcium concentration to 40.65?5.65nmol/L. NMDA increase Markedly calcium fluorescent intensity, the effects of NMDA was decreased notably after pre-treating with aqueous extract from Lishi No.5 formula. The effect of MK-801, an antagonist of NMDA receptor, on inhibition of NMDA increasing free calcium fluorescent intensity was significantly reduced after pretreatment of aqueous extract from Lishi No.5 formula. Conclusion Aqueous extract from Lishi No.5 formula maybe bidirectional adjust intracellular free calcium concentration via enhancing L-type calcium channel activity and blocking NMDA receptor in part.