维拉帕米增强猴肾上皮细胞低密度脂蛋白受体活性

Enhancement on expression of LDL receptors in cultured rhesus renal epithelial cells by verapamil

本文用放射配体法观察了维拉帕米(Ver)对恒河猴肾上皮细胞LDL受体活性的影响,发现Ver以浓度和时间依赖的方式明显增强受体介导的结合和内移过程,对降解的影响不显著。Ver作用浓度为44 mmol·L^(-1)效应最明显。

In order to investigate the anti-atherogenic properties of calcium antagonists, human serum low density lipoproteins (LDL) were isolated by density gradient ultracen-trifugation and iodinated with 125I by iodine monochloride method. Effects of verapamil on activity of LDL receptors in cultured rhesus renal epithelial cells were examined by radio-ligand analysis. The receptor-mediated binding, internalization, and degradation of cultured cells pretreated with verapamil 4 4 mmol · L-1 for 2 4 h and cells pretreated for 2 4 h and incubated for 10 h with verapamil were increased compared with control group (61 ± 11, 52 ± 8 vs 20±3. 5, 1006 ± 106, 579 ± 124 vs 253 ± 78, 630 ± 43, 541 ± 4 6vs 374 ± 53 125I-LDL/μg·g-1 cell protein). In verapamil-treated cells without verapamil pretreatment, increased internalization and degradation were not significant, and binding was not increased. When the cells were pretreated with verapamil 22 mmol·L-1 for 24 h and then incubated with 5, 20, 50 125I-LDL/mg · L-1, binding and internalization were increased , increased degradation was seen only with 5 0 125 I-LDL/mg · L-1. The results indicated that the verapamil enhances expression of LDL receptor in cultured rhesus renal epithelial, cells, which might contribute to the protective effects of calcium antagonists in experimental and human atherosclerosis.