Objective: To investigate the effect of serum containing Liuwei Dihuang Wan on calcium concentration and the level of calmodulin-dependent protein kinase Ⅱ(CaMKⅡ) mRNA in PC12 cells induced by KCl. Method: The models of PC12 cells was established (rat adrenal pheochromocytoma cell line) by being stimulated by 150 mmol· L-1 KCl. Then Dulbecco's modified Eagle's medium (DMEM) containing 10% Liuwei Dihuang Wan serum was added to exponentially-growing PC12 cells for pre-protection. After 48 h

the proliferation of PC12 cells was detected by MTT and the calcium concentration in PC12 cells was observed by laser scanning confocal microscope. The level of CaMKⅡmRNA was analyzed by RT-PCR. Result: It can significantly improve the activity of cells in traditional Chinese medicine treatment group(1.15±0.09)

compared with the model group (0.47±0.11)

(P<0.01). It can significantly reduced the mean fluorescence intensity of calcium in PC12 cells induced by KCl (150 mmol·L-1) in traditional Chinese medicine treatment group compared with the model group(P<0.05). The basic calcium intensity in PC12 cells was down-regulated in traditional Chinese medicine pre-protection group compared with the control group and the model group. In addition

the level of CaMKⅡmRNA in traditional Chinese medicine treatment group was up-regulated compared with that in model group (P<0.05). Conclusion: The serum containing with 10% Liuwei Dihuang Wan can effectively inhibit the intracellular calcium overload induced by KCl and improve the expression of CaMKⅡmRNA in PC12 cells.