摘要
为研究垂体腺苷酸环化酶激活肽对内皮细胞表面低密度脂蛋白受体分布的影响，以胶体金─低密度脂蛋白为示踪物，结合透射电镜技术观察垂体腺苷酸环化酶激活肽作用于体外培养的内皮细胞后，其表面低密度脂蛋白受体分布变化情况。结果表明，垂体腺苷酸环化酶激活肽作用于内皮细胞后，内皮细胞光镜及电镜下的形态与对照组无明显差异，但内皮细胞表面低密度脂蛋白受体分布发生了变化，胶体金─低密度脂蛋白颗粒单独出现率升高（P＜0．05），内皮细胞内吞胶体金─低密度脂蛋白减少。提示垂体腺苷酸环化酶激活肽可能通过影响内皮细胞表面低密度脂蛋白受体的分布状态而减少低密度脂蛋白入胞代谢，进而减少低密度脂蛋白通过内皮细胞进入内膜下的机会，从而在抗动脉粥样硬化方面发挥作用。
Aim: To investigate the distribution change of low density lipoprotein (LDL) receptors on the surface of EC effected by PACAP for understanding the potential mechanism of PACAP in atherosclerosis.Methods: EC were cultured with M199 containing 10-8 mol/L PACAP(PACAP groups) and M199 (control groups) respectively for 24 h, then incubated with 0. 5% BSA-M199-colloidal gold LDL conjugate solution for 2 h at 4℃. In addition, some of EC were warmed to 37℃ for 2 h to initiate endocytosis. Sections of 60 nm thickness were cut and observed with a HITACHIH-600 transmission electron microscope.Results: Colloidal gold LDL conjugate in control group often appeared in cluster, randomly distributed on the surface of EC and the percentage of clustering appearance was 65%. Effected by PACAP for 24 h,the percentage of single colloidal gold LDL conjugate increase to 50%, compared with control groups (P<0. 05). Warmed to 37℃ for 2 h, the EC of PACAP groups could decrease endocytosis of colloidal gold LDL conjugate.Conclusion: After PACAP treatment, compared with the control group, the percentage of single colloidal gold LDL conjugate granule appear in each cluster of EC seems to be increased and the endocytosis of colloidal gold LDL conjugate granules decreased.The change of distribution of singIe colloidal gold LDL conjugate granule represent less LDL receptors located on the surface of EC and can decrease transportation of LDL though EC when clusters are not formed.Thus, our results suggest that PACAP play an important role in the function of antiatherosclerosis.
出处
《中国动脉硬化杂志》
CAS
CSCD
1998年第2期105-108,共4页
Chinese Journal of Arteriosclerosis
