特立帕肽对尿毒症腹膜透析大鼠钙磷代谢紊乱的作用及其机制探讨

Effect and mechanism of teriparatide on the disorder of calcium and phosphorus metabolism in uremic rats undergoing peritoneal dialysis

摘要:

目的 探究特立帕肽通过Wnt/β-catenin通路对尿毒症腹膜透析大鼠钙磷代谢紊乱的影响。方法 取50只SPF级SD雄性大鼠复制尿毒症模型，模型复制过程中死亡2只，随机取12只大鼠为尿毒症组，剩余36只大鼠随机分为尿毒症腹膜透析假手术组、尿毒症腹膜透析组、特立帕肽组，每组12只。特立帕肽组成功复制尿毒症腹膜透析大鼠模型后，腹腔注射特立帕肽30 μg/（kg·d），1次/d，连续6周；尿毒症组、尿毒症腹膜透析组、尿毒症腹膜透析假手术组同时间腹腔注射等量生理盐水。采用酶联免疫吸附试验测定血肌酐、血尿素氮及血钙、血磷水平；苏木精-伊红染色观察肾组织病理学变化；Western blotting测定肾组织Wnt/β-catenin通路蛋白的表达。结果 与尿毒症组、尿毒症腹膜透析假手术组比较，尿毒症腹膜透析组、特立帕肽组大鼠血肌酐、血尿素氮水平升高（P <0.05）；且特立帕肽组大鼠血肌酐、血尿素氮水平低于尿毒症腹膜透析组（P <0.05）。与尿毒症组、尿毒症腹膜透析假手术组比较，尿毒症腹膜透析组、特立帕肽组大鼠血钙水平降低（P <0.05），血磷水平升高（P <0.05）；且特立帕肽组大鼠血钙水平高于尿毒症腹膜透析组（P <0.05），血磷水平低于尿毒症腹膜透析组（P <0.05）。与尿毒症组、尿毒症腹膜透析假手术组比较，尿毒症腹膜透析组、特立帕肽组大鼠肾组织Wnt、β-catenin蛋白相对表达量降低（P <0.05）；且特立帕肽组大鼠肾组织Wnt、β-catenin蛋白相对表达量低于尿毒症腹膜透析组（P <0.05）。结论 特立帕肽可改善尿毒症腹膜透析大鼠肾功能，提高血清钙、磷水平，进而改善尿毒症腹膜透析大鼠钙磷代谢紊乱，其作用可能是通过抑制Wnt/β-catenin通路活化来实现的。

Abstract:

Objective To explore the effect of teriparatide on the disorder of calcium and phosphorus metabolism in uremic rats undergoing peritoneal dialysis.Methods We successfully established 36 rat models of peritoneal dialysis and they were randomly divided into sham operation group, peritoneal dialysis group and teriparatide group with 12 rats in each group, while another 12 uremic rats were taken as uremic group. The rats in teriparatide group were given intraperitoneal injection of teriparatide at a dose of 30 μg/(kg·d), once a day for 6 weeks, after successful modeling of peritoneal dialysis. The uremic group, peritoneal dialysis group and sham operation group were intraperitoneally injected with an equal volume of normal saline at the same time. The levels of serum creatinine, blood urea nitrogen, and serum calcium and phosphorus were measured by enzyme-linked immunosorbent assay (ELISA). Hematoxylin and eosin (HE) staining was used to observe the pathological changes of renal tissues. The expressions of proteins associated with the Wnt/β-catenin pathway in renal tissues were measured by Western blotting.Results Compared with the uremic group and the sham operation group, the levels of serum creatinine and blood urea nitrogen were increased in the peritoneal dialysis group and teriparatide group (P < 0.05). Besides, the levels of serum creatinine and blood urea nitrogen in the teriparatide group were lower than those in the peritoneal dialysis group (P < 0.05). In comparison with the uremic group and the sham operation group, the concentration of serum calcium was lower, but that of serum phosphorus was higher in the peritoneal dialysis group and teriparatide group (P < 0.05). Moreover, the concentration of serum calcium was higher and that of serum phosphorus was lower in the teriparatide group compared with the peritoneal dialysis group (P < 0.05). The relative protein expressions of Wnt and β-catenin were decreased in the peritoneal dialysis group and teriparatide group relative to those in the uremic group and the sham operation group (P < 0.05), and they were even lower in the teriparatide group compared with the peritoneal dialysis group (P < 0.05).Conclusions Teriparatide can improve the renal function of uremic rats undergoing peritoneal dialysis, increase the concentrations of serum calcium and phosphorus, and alleviate the disorder of calcium and phosphorus metabolism. The protective effects of teriparatide may be attributed to the inhibition of the activation of Wnt/β-catenin pathway.