糖尿病大鼠肾脏水通道蛋白－2 mRNA的表达及黄茂的调节作用

Aim To investigate the changes of renal medullary aquaporin-2 (AQP-2) in rats with diabetes mellitus (DM) induced by streptozotocin (STZ) and the therapeutical effect of astragalus membranacens (AM). Methods Thirty diabetes mellitus rats induced by STZ were randomly divided into three groups: DM group, AM low dosage group (5 g•kg^(-1)•d^(-1)), AM high dosage group (10 g•kg^(-1)•d^(-1)). Another 10 normal rats were taken as the control group. The drug was given by intraperitonial injection for 6 weeks. Blood glucose, serum insulin and C-Peptide were recorded. A 24 h urine collection through metabolic cage was made to measure urinary volume; the RT-PCR technique was used to determine the levels of aquaporin-2 mRNA expression in kidney medulla. Results After STZ treatment, diabetic rats showed higher glucose and lower insulin, C-Peptide levels as compared with control rats. AM treatment had no effect on blood glucose, serum insulin and C-Peptide, but it could significantly increase the urinary volume of diabetic rats. The expression of AQP-2 mRNA was up-regulated in renal medulla of diabetic rats, AM treatment could alleviate the expression of AQP-2 mRNA. Conclusion The therapeutical effect of AM on diabetes mellitus may be related to the significantly decreased expression of AQP-2 in the kidney medulla.