目的 观察佛波酯（PMA）慢性处理大鼠血管平滑肌细胞各亚型蛋白激酶C （PKCs）表达的影响。方法 原代培养大鼠血管平滑肌细胞，①按照PMA处理浓度将细胞随机分为空白组、0.25‰ DMSO组和PMA1、5、10 μmol/L组，各组细胞均处理4 h；②按照PMA处理时间将细胞随机分为空白组、0.25‰ DMSO组和PMA 1、4和24 h组，PMA组的药物浓度均为10 μmol/L。采用Western blotting技术检测各亚型PKCs蛋白的表达。结果 PMA浓度＜10 μmol/L处理细胞时间＜4 h不影响PKC-α的表达（P>0.05），10 μmol/L PMA处理24 h能抑制PKC-α的表达（P<0.05）；PMA浓度＞5 μmol/L处理细胞时间＞4 h可明显抑制PKC-δ的表达（P<0.01），PMA浓度＜5 μmol/L处理细胞时间＜4 h对PKC-ε的表达无显著影响（P>0.05），10 μmol/L PMA处理细胞1 h即可明显抑制PKC-ε的表达（P<0.01）；PMA浓度＞5 μmol/L处理细胞时间＞4 h可以明显抑制PKC-θ的表达（P<0.01）；10 μmol/L的PMA处理细胞24 h对 PKC-ξ的表达无明显影响（P>0.05）。结论 PMA慢性处理大鼠血管平滑肌细胞可抑制传统型PKC-α和新型PKC-δ、ε、θ的表达，对非典型PKC-ζ的表达没有影响。

Objective To investigate the changes of protein kinase C (PKC) isoforms in rat vascular smooth muscle cells (VSMCs) treated with prolonged incubation of phorbol-12-myristate-13-acetate (PMA). Methods Primary rat vascular smooth muscle cells cultured in vitro were divided into blank group, 1, 5, and 10 μmol/L PMA-treated groups, and 0.25‰ DMSO-treated group, and all cells were treated for 4 h. The other cells were treated with 10 μmol/L PMA for 1, 4, and 24 h and with 0.25‰ DMSO for 24 h. The levels of PKCs were measured using Western blotting. Results In 1, 5, and 10 μmol/L PMA-treated groups for 4 h, the levels of PKC-α had no significant changes (P>0.05), while in 10 μmol/L PMA-treated group for 24 h, PKC-α was down-regulated significantly (P<0.05). PKC-δ expression was down-regulated obviously in VSMCs treated with PMA (>5 μmol/L for over 4 h)(P<0.01). PKC-ε expression had no changes in PMA-treated groups (<5 μmol/L shorter than 4 h) (P>0.05), while PKC-ε decreased remarkably in PMA group (10 μmol/L for 1 h)(P<0.01). PKC-θ expression was down-regulated obviously in VSMCs treated with PMA (>5 μmol/L for over 4 h)(P<0.01). Level of PKC-ζ had no changes in PMA group (10 μmol/L for 24 h)(P>0.05). Conclusion Prolonged treatment with PMA down-regulated classical PKC-α and novel PKC-δ, ε, and θ in VSMCs, while had no effect on atypical PKC-ζ.