钙调素拮抗剂三氟拉嗪对犬肾上皮细胞增殖的影响

Effects of trifluoperazine,a calmodulin antagonist,on proliferation of MDCK cells in vitro

为探讨钙调素拮抗剂三氟拉嗪(TFP)对犬肾上皮细胞(MDCK)增殖的抑制作用及对细胞各周期时相的影响,采用细胞计数法、流式细胞术、[γ-32P]ATP掺入外源性底物的液体闪烁法和免疫组化技术,分别测定5、10和15μmol/L浓度的TFP对MDCK细胞增殖的抑制作用、细胞各周期时相的百分率、胸苷激酶(TK)的活性以及增殖细胞核抗原(PCNA)表达的阳性率。结果表明:给药3 d后,各浓度TFP对MDCK细胞生长均具有明显抑制作用;G0/G1期的细胞比率均显著增加(P<0.05),而S期、G2/M期细胞的比率则有所下降,其中高浓度TFP组显著下降(P<0.05);细胞内TK的活性和PCNA的表达显著降低,呈明显的时间剂量效应关系。说明TFP可通过阻断钙调素信号通路,影响DNA合成和细胞周期而抑制MDCK细胞的增殖。

The objective of this study was to explore the effects of trifluoperazine on the proliferation of Mardin-Darby canine kidney ceils （MDCK）. Cytometry was used to determine the suppressive effects of different concentrations of trifluoperazine on proliferation of MDCK cells, The percentage of different cell cycles was measured by Flow cytometry. The activity of thymidine kinase （TK） in MDCK cells induced at varying concentrations of trifluoperazine was detected by incorporation of [γ-^32p] ATP into an exogenous substrate. The expression of PCNA was detected by immunohistochemistry after exposure to TFP for 72 h. The results showed that= 1） Trifluoperazine markedly inhibited the proliferation of MDCK cells after 72 hours culture at concentrations of .5, 10 and 1.5μmol/L. 2） The percentage of cells in S and G2/ M phase decreased gradually and that in Go/G1 increased significantly, 3） The intracellular TK activity was suppressed with trifluoperazine. 4） The positive rate of PCNA decreased with the increase in TFP, especially in cells treated with higher concentrations of TFP. The results indicated that trifluoperazine could significantly suppress the proliferation of MDCK cells in vitro, probably by inactivating the CaM signal transduction pathway and changing the normal cell cycle.