目的：探讨桑白皮的利尿作用及发挥利尿作用的有效部位。方法：采用大鼠代谢笼法，首先观察桑白皮水煎液的利尿作用，连续给药5天，筛选出发挥利尿作用的最佳剂量，并用苦味酸法检测给药5天后血清和尿液中肌酐的含量；进而研究桑白皮各化学拆分组分的利尿作用，确定桑白皮发挥利尿作用的有效部位。结果：桑白皮水煎液给药第3—5天后，与对照组相比，大鼠尿量明显增加（P<0.05或P<0.01），且中剂量利尿效果最为显著（P<0.01）；桑白皮水煎液对血肌酐、尿肌酐含量没有显著影响；各化学拆分组分利尿结果显示，与对照组相比，30%乙醇组分和脂肪油组分利尿作用最好（P<0.01）。结论：桑白皮水煎液具有明显的利尿作用，且发挥利尿作用的物质基础主要集中在30%乙醇组分和脂肪油组分。

This study was aimed to investigate the diuretic effect of Mori Cortex and to identify effective fractions in M. Cortex. Metabolic cages were used to firstly observe the diuretic effect of M. Cortex aqueous extracts on rats. Medications were continuously given for 5 days to screen for the best dosage of diuretic effect. Picric acid assays were used to detect creatinine levels in serum and urine after 5-day medication. Then, the diuretic effect of each chemical split fraction in M. Cortex was studied in order to indentify the effective parts. The results showed that after administration of M. Cortex aqueous extracts for 3 to 5 days, compared with the control group, there was a significant diuretic effect on rats (P<0.05 or P<0.01). And the medium-dose of M. Cortex aqueous extracts showed the best effect (P<0.01). However, M. Cortex aqueous extracts had no significant effect on creatinine levels in serum and urine. Assays of diuretic effect of chemical split fractions of M.Cortex indicated that compared with the control group, 30% ethanol fraction and fatty oil fraction had the best diuretic effect (P<0.01). It was concluded that M.Cortex aqueous extracts had a significant diuretic effect. And the chemical fractions contributed mostly to this effect were mainly existed in the 30% ethanol fraction and fatty oil fraction.

科学技术部国家重点基础研究发展计划“973计划”项目（2013CB531802）：宣泻利水中药的药性研究，负责人：郑晓珂。