基于调控结肠组织中SCF和c-kit mRNA表达分析苍术燥性效应量效关系

目的：基于结肠组织中干细胞因子（SCF）及其受体c-kit mRNA表达分析苍术燥性效应的量效关系，确定引起小鼠燥性反应的苍术基础剂量，为临床用药提供参考。方法：75只C57BL/6小鼠分为对照组和185、370、555及740 mg·kg^-1苍术挥发油组，每组15只，给药体积为0.015 mL·g^-1，灌胃给药14 d，对照组给予同体积1%吐温-20溶液。测定小鼠日均饮水量和日均尿量，采用免疫组织化学法检测小鼠肾组织中水通道蛋白2（AQP2）蛋白表达水平，计算小鼠脾脏和肾脏系数，采用RT-PCR法检测小鼠结肠组织中SCF和c-kit mRNA表达水平，根据以上指标考察各组小鼠燥性效应。结果：与对照组比较，185和370 mg·kg^-1苍术挥发油组小鼠日均饮水量、日均尿量、肾组织中AQP2蛋白表达水平、肾脏系数和脾脏系数差异均无统计学意义（P>0.05），小鼠结肠组织中SCF mRNA表达水平明显升高（t=4.859，P<0.01；t=6.651，P<0.05），185 mg·kg^-1苍术挥发油组小鼠结肠组织中c-kit mRNA表达水平明显升高（t=2.946，P<0.05），而370 mg·kg^-1苍术挥发油组差异无统计学意义（P>0.05）；与对照组比较，555 mg·kg^-1苍术挥发油组小鼠日均尿量、结肠组织中c-kit mRNA表达水平明显降低（t=7.708，P<0.01；t=8.465，P<0.01），其他指标差异无统计学意义（P>0.05）；与对照组比较，740 mg·kg^-1苍术挥发油组小鼠饮水量、肾组织中AQP2蛋白表达水平明显升高（t=3.554，P<0.01；t=4.636，P<0.01），日均尿量、脾脏系数、结肠组织中SCF和c-kit mRNA表达水平明显降低（t=7.708，P<0.01；t=4.985，P<0.01；t=7.314，P<0.01；t=28.45，P<0.01）。结论：低剂量（185和370 mg·kg^-1）苍术挥发油对健康小鼠无明显燥性作用，而高剂量（555 mg·kg^-1以上剂量）苍术挥发油可能通过影响SCF/c-kit信号通路对小鼠产生明显的燥性作用。

Analysis on dose-effect relationship of Atractylodes Rhizoma dryness effect based on regulation of SCF and c-kit mRNA expressions in colon tissue

Objective: To analyze the dose-effect relationship of dryness effect of Atractylodes Rhizoma based on the expressions of stem cell factor (SCF) and its receptor c-kit mRNA in colon tissue and to ensure the basic dose of Atractylodes Rhizoma which caused the dryness reaction in the mice,and to provide the reference for clinical medicine. Methods: Seventy-five C57BL/6 mice were divided into control group,185, 370, 555, and 740 mg·kg^-1 Atractylodes oil groups, 15 mice in each group, and the administration volume was 0.015 mL·g^-1;the mice were administered intragastrically for 14 d,and the mice in control group were given the same volume of 1% Tween-20 solution. The average daily water intake and daily average urine output of the mice were detected. Immunohistochemical method was used to detect the expression levels of aquaporin-2 (AQP2) in the kidney tissue of the mice;the sleen and kidney coefficients of the mice were calculated, and RT-PCR method was used to determine the expression levels of SCF and c-kit mRNA in the colon tissue; the dryness effects of the mice in various groups were investigated according the obove indicatros. Results: Compared with control group, the average daily water intakes, daily urine outputs,the AQP2 expression levels in kidney tissue,the kidney coefficients and spleen coefficients of the mice in 185 and 370 mg·kg^-1 Atractylodes oil groups had no significant differences (P>0.05); the expression levels of SCF mRNA in colon tissue of the mice were significantly increased (t=4.859, P<0.01; t=6.651, P<0.05); the expression level of c-kit mRNA in colon tissue of the mice in 185 mg·kg^-1 Atractylodes oil group was significantly increased (t=2.946, P<0.05), but in 370 mg·kg^-1 Atractylodes oil group had no statistically significant difference(P<0.05).Compared with control group, the average daily urine output and the expression level of c-kit mRNA in colon tissue of the mice in 555 mg·kg^-1 Atractylodes oil group were significantly reduced (t=7.708, P<0.01; t=8.465, P<0.01), but there were no statistically significant differences in other indicators (P>0.05). Compared with control group, the water intake and the AQP2 protein expression level in kidney tissue of the mice in 740 mg·kg^-1 Atractylodes oil group were significantly increased (t=3.554, P<0.01; t=4.636, P<0.01),and the average daily urine volume, the spleen coefficient,and the expression levels of SCF and c-kit mRNA in colon tissue of the mice were decreased significantly (t=7.708, P<0.01; t=4.985, P<0.01; t=7.314, P<0.01; t=28.45, P<0.01). Conclusion: Low doses (185 and 370 mg·kg^-1) of Atractylodes oil show no obvious dryness effect in the healthy mice, and the high doses(555 mg·kg^-1 and above) of Atractylodes oil may show obvious dryness effect by influencing the SCF/c-kit signal pathway.