钠依赖性葡萄糖转运体介导红景天苷在大鼠肠中吸收

目的：研究红景天苷在大鼠小肠上吸收饱和现象和钠依赖性葡萄糖糖转运体（SGLT1）是否参与其的吸收。方法：测定大鼠灌胃12，24和48mg·kg^-1红景天苷后的血药浓度一时间数据和估算相应药物代谢动力学参数。分析在SGLT1的抑制剂根皮苷存在情况下红景天苷在大鼠空肠的肠外囊中摄取，研究在链脲佐菌素诱导的糖尿病大鼠吸收动力学，并用在体肠灌流技术测定红景天苷在空肠中的有效渗透系数。结果：大鼠灌胃24和48mg·kg^-1红景天苷后，它们的血药浓度-时间曲线几乎重合，两种剂量的药物代谢动力学参数也相似，提示吸收存在饱和现象。肠外翻实验结果显示红景天苷的吸收是浓度依赖性的，根皮苷浓度依赖性抑制红景天苷的吸收。红景天苷在糖尿病大鼠胃肠道的吸收快于正常大鼠，且其有效渗透系数也高。结论：红景天苷在大鼠小肠上存在吸收饱和现象，SGLT1可能参与红景天苷的吸收调节。

Sodium-dependent Glucose Transporter Was Involved in Salidroside Absorption in Intestine of Rats

AIM： To report saturable absorption process of salidroside in rat intestine and investigate whether Na^＋-dependent glucose transporter （SGLTI） was involved in the absorption of salidroside. METHOD： Rats orally received 12, 24 and 48 mg·kg^-1 of salidroside, plasma concentrations were measured and corresponding pharmacokinetic parameters were estimated. Everted gut sleeves from the jejunum of rats were used for assaying the uptakes of salidroside in absences or presence of SGLT1 inhibitor phlorizin. Absorption of salidroside was investigated in diabetic rats induced by streptozotocin （STZ） and effective permeability coefficients in the jejunum of rats was carried out using in situ intestine perfusion. RESULTS： Plasma concentration-time profiles were completely overlapped, following oral dose 24 and 48 mg·kg^-1 of salidroside, accompanied by similar pharmacokinetic parameters. Salidroside uptake by the rat everted gut sleeves was concentration-dependent and SGLTI inhibitor phlorizin might inhibit the uptake in a concentration-dependent manner. Salidroside was absorbed faster in gastro intestines of diabetic rats than it did in normal rats, accompanied by higher effective permeability coefficients. CONCLUSION： Saturable absorption process of salidroside occurred in rat intestine and SGLT1 may be involved in the process of salidroside absorption.