目的：从定量角度分析垂体腺苷酸环化酶激活肽（ＰＡＣＡＰ）对血管平滑肌细胞（ｖＳＭＣ）增殖的影响。方法：以培养的猪肺动脉ＳＭＣ为实验对象，免疫组织化学ＬＳＡＢ法检测ＳＭＣ中增生细胞核杭原（ＰＣＮＡ），Ｔｉｇｅｒ９２０Ｇ细胞图象分析仪上测量计算各组细胞中ＰＣＮＡ阳性细胞的百分率；并检测阳性细胞的平均光密度（ＡＯＤ）和积分光密度（ＩＯＤ），计算阳性水平指数（ＰＬＩ）。结果：ＰＡＣＡＰ组ＳＭＣ的ＰＣＮＡ阳性率显著低于对照组细胞（Ｐ＜０．０１）；ＡＯＤ、ＩＯＤ及ＰＬＩ值也显著低于对照组（Ｐ＜００１）。结论：ＰＡＣＡＰ能抑制培养的ｖＳＭＣ增殖，可能具有抗动脉粥样硬化作用 Objective: To quantitatively analyze the effect of pituitary adenylate cyclase activating peptide (PACAP) on the proliferation of vascular smooth muscle cells (vSMC). Methods: The cultured porcine pulmonary artery SMC was used as the experimental group. Immunohistochemical LSAB method was used to detect the percentage of PCNA positive cells in each group of cells in the proliferating cell nucleus-cytoplasm (PCNA) and Tiger920G cell image analyzer of SMC. The average optical density (AOD) and integral optical density (IOD) of the cells were calculated to calculate the positive level index (PLI). Results: The positive rate of PCNA in PACAP group was significantly lower than that in control group (P <0.01). The AOD, IOD and PLI values ​​in PACAP group were also significantly lower than those in control group (P <001). CONCLUSIONS: PACAP inhibits the proliferation of cultured vSMCs and may have anti-atherogenic effects