链脲佐菌素诱导的糖尿病大鼠尿podocalyxin排泄的动态变化

Dynamic changes of urinary podocalyxin excretion and its significance in STZ-induced diabetic rats

目的观察链脲佐菌素(STZ)诱导的糖尿病大鼠足细胞标志蛋白podocalyxin随尿排泄的动态变化并探讨其意义。方法 STZ 65 mg/kg腹腔注射后建立糖尿病大鼠模型,正常大鼠注射等量枸橼酸缓冲液作为对照组(NC组)。分别于0周、2周、4周和8周监测两组大鼠血糖、尿白蛋白(UALB)及尿沉渣中PCX含量(UPCX)和8周末HbA1c,为消除尿量影响分别用尿肌酐(UCr)校正称为UACR(UALB/UCr)及UPCR(UPCX/UCr)。结果 (1)与健康对照组比较,糖尿病大鼠各时间点血糖和8周时HbA1c显著增高,P<0.01;(2)与健康对照组比较,2周时糖尿病大鼠UACR及UPCR即显著增高,并随时间不断增长;(3)糖尿病大鼠UPCR与UACR呈正相关(r=0.86,P<0.01)。结论足细胞损伤参与糖尿病肾脏病变的发生,尿PCX检测可作为反映糖尿病早期肾损害的指标之一。

Objective To investigate the dynamic changes of urinary podocalyxin excretion and its clinical significance in streptozotocin-induced diabetic rats.Methods Diabetic models were established by a single injection of streptozotocin（STZ 65 mg/kg）,then the diabetic rats were assigned into diabetic group after the diabetic model stabilized for one week,healthy rats injected with equal dosage of critic acid buffer solution were served as normal control group（NC group）.The peripheral blood glucose,urinary sediment podocalyxin,urinary albumin were determined at the basal,the second week,the fourth week and eighth week in two groups during the observation.To eliminate the impact of urine volume,urinary podocalyxin and urinary albumin concentrations were expressed as urinary UPCX/UCr（UPCR）and UALB/UCr（UACR）,respectively.Results（1）Compared with NC group,the levels of blood glucose throughout the study period along with HbA1c at the 8th week in diabetic rats were significantly higher than those in group NC at the same period（P0.01）.（2）The level of UACR and UPCR in diabetic model group began to increase significantly at the third weeks after the STZ injection,then increased progressively with the time until the end of the experiment.（3）UPCR was positively related with UACR（r=0.86,P0.01）.Conclusion Podocyte injury involves in the development of diabetic nephropathy.Increased urinary podocalyxin excretion appears to be an early biomarker of diabetic kidney injury.