Stimulatory effect of trans-cinnamaldehyde on norepinephrine secretion in cultured pheochromocytoma (PC-12) cells  

作　　者：TSAI Chin-Chuan 

机构地区：[1]Department of Traditional Medicine, School of Post-Baccalaureate Chinese Medicine, China Medical College, Taichung City, Taiwan 40401

出　　处：《Acta Pharmacologica Sinica》2000年第12期119-123,共5页中国药理学报（英文版）

摘　　要：AIM: The effect of trans-cinnamaldehyde (CNMA) on the release of norepinephrine (NE) from nerve terminal was investigated using rat pheochromocytoma 12 (PC-12) cells. METHODS: The amount of NA released from PC-12 cells incubated with CNMA or related substances was quantified by high performance liquid chromatogra-phy (HPLC)-electrochemical detection. The lipophilic anion bisoxonol was used to monitor the effect of CNMA on the membrane potential. RESULTS: CNMA stimulated the secretion of NE in a concentration-dependent manner from 5 μmol/L to 50 μmol/L, while the value of lactate dehydrogenase in the incubated medium was not influenced by CNMA. However, acetaldehyde, cinnam-ic acid, cinnamoyl chloride and cinnamamide failed to produce similar effect. The action of CNMA can thus be considered specific. The depolarizing effect of CNMA on the membrane potential was also illustrated by a concentration-dependent increase in the fluorescence of bisoxonol , a potential-sensitive dye. Saxitoxin attenuatedAIM: The effect of trans-cinnamaldehyde (CNMA) on the release of norepinephrine (NE) from nerve terminal was investigated using rat pheochromocytoma 12 (PC-12) cells. METHODS: The amount of NA released from PC-12 cells incubated with CNMA or related substances was quantified by high performance liquid chromatogra-phy (HPLC)-electrochemical detection. The lipophilic anion bisoxonol was used to monitor the effect of CNMA on the membrane potential. RESULTS: CNMA stimulated the secretion of NE in a concentration-dependent manner from 5 μmol/L to 50 μmol/L, while the value of lactate dehydrogenase in the incubated medium was not influenced by CNMA. However, acetaldehyde, cinnam-ic acid, cinnamoyl chloride and cinnamamide failed to produce similar effect. The action of CNMA can thus be considered specific. The depolarizing effect of CNMA on the membrane potential was also illustrated by a concentration-dependent increase in the fluorescence of bisoxonol , a potential-sensitive dye. Saxitoxin attenuated the depolarizing action of CNMA at concentrations sufficient to block sodium channels. Besides, the effect of CNMA to depolarize the membrane potential in PC-12 cells is greater than that of 4-aminopyridine (4-AP). The action of CNMA on NE releasing depends on extracellular Ca2+ and is attenuated by 8-bromo-cAMP at concentrations sufficient to inhibit the action of cyclic AMP. CONCLUSION: These findings suggest that CNMA can depolarize the membrane to result in a Ca2+ -dependent and cyclic AMP-related release of NE from PC-12 cells.

关 键 词：PC12 CELLS CINNAMALDEHYDE bisox-onol SAXITOXIN 4-AMINOPYRIDINE NOREPINEPHRINE 

分 类 号：R96[医药卫生—药理学]