目的 比较不同剂量地塞米松联合复方地芬诺酯、限水法诱导的SD大鼠阴虚型便秘模型，为进一步研究阴虚型便秘提供适用的大鼠模型。方法 将24只雄性SD大鼠分为对照组和地塞米松低、中、高剂量（0.088、0.175、0.350 mg·kg_-1）组，地塞米松组分别ig地塞米松溶液和10 mg·kg_-1的复方地芬诺酯混合液，连续14 d，并结合限制饮水，约每只每天20 mL·d^-1；对照组大鼠ig等体积的CMC-Na溶液（溶媒），保持自由饮食、饮水。检测大鼠一般状况及排便情况、体质量、脏器指数、24 h粪便湿质量与含水量，试剂盒法检测血清环磷酸腺苷（cAMP）、环磷酸鸟苷（cGMP）、促肾上腺皮质激素（ACTH）、皮质酮（CORT）水平，胭脂红法检测首粒红便排出时间，炭末推进实验检测小肠推进率，苏木精-伊红（HE）染色检测结肠组织病理学变化，Western blotting检测胆碱乙酰转移酶（ChAT）、神经元型一氧化氮合酶（nNOS）、结肠酪氨酸激酶受体蛋白（c-kit）、干细胞因子（SCF）蛋白表达情况；后续取20只雄性SD大鼠进行模型稳定性验证：设置对照组和地塞米松（0.175 mg·kg_-1）组，造模14 d后观察7 d死亡率。结果 阴虚指标方面：地塞米松低、中、高剂量组大鼠耳、鼻、唇、尾光泽暗淡，毛色发黄无光泽，易惊，怕人，体温上升，小便发黄，自主活动增加，易被激惹，反应活跃，中、高剂量组大鼠表现较为明显；大鼠体质量、脾脏及胸腺指数均显著低于对照组（P＜0.01）；地塞米松中、高剂量组大鼠血清cAMP、cAMP/cGMP、CORT显著高于对照组（P＜0.05、0.01）；地塞米松低、中、高剂量组血清ACTH水平显著高于对照组（P＜0.05、0.01），以上指标均呈剂量相关性。便秘指标方面：地塞米松组大鼠粪便干结、表面无光泽、粗糙且多褶皱，呈球状、质硬；地塞米松低、中、高剂量组24 h粪便湿质量均显著低于对照组（P＜0.01），24 h粪便含水量均显著低于对照组（P＜0.05、0.01），首粒红便排出时间显著高于对照组（P＜0.05），小肠推进率显著低于对照组（P＜0.05、0.01），结肠组织病理损伤明显，结肠ChAT、c-kit、SCF蛋白表达显著低于对照组（P＜0.05、0.01），nNOS蛋白表达显著高于对照组（P＜0.05、0.01）。造模第14天，地塞米松高剂量组出现大鼠死亡，其余各组无死亡情况。后续对造模效果较好的中剂量进行模型稳定性验证，所有大鼠在长达21 d的实验期内均未死亡，说明中剂量具有良好的安全性。结论 综合阴虚指标及便秘指标，0.175 mg·kg_-1地塞米松复合10 mg·kg_-1复方地芬诺酯联合限水法可模拟“阴液不足、虚热内生”的中医病机，是构建SD大鼠阴虚型便秘模型较适宜的剂量。

Objective To compare the effects of different doses of dexamethasone combined with compound diphenoxylate in inducing a yin deficiency constipation model in SD rats, aiming to establish a more suitable rat model for future research on this condition. Methods Twenty-four male SD rats were divided into a control group and three dexamethasone groups with low, medium and high doses (0.088, 0.175 and 0.350 mg·kg^-1). Rats in the dexamethasone groups were ig administered dexamethasone solution and a mixture of 10 mg·kg^-1 compound diphenoxylate for 14 consecutive days, and their water intake was restricted to approximately 20 mL per rat per day. Rats in the control group were ig administered the same volume of CMC-Na solution (vehicle) and maintained free access to food and water. The general condition and defecation status, body weight, organ index, 24 h wet weight and water content of feces were measured. The levels of serum cyclic adenosine monophosphate (cAMP), cyclic guanosine monophosphate (cGMP), adrenocorticotropic hormone (ACTH), and corticosterone (CORT) were detected by kit method. The time of first red stool excretion was detected by carmine red method. The small intestinal propulsion rate was detected by charcoal meal propulsion test. The pathological changes of colon tissue were detected by hematoxylin-eosin (HE) staining. The protein expression of choline acetyltransferase (ChAT), neuronal nitric oxide synthase (nNOS), c-kit and stem cell factor (SCF) was detected by Western blotting. Subsequently, 20 male SD rats were used to verify the stability of the model: a control group and a dexamethasone (0.175 mg·kg^-1) group were set up. The mortality rate was observed for 7 days after 14 days of modeling. Results weight of feces in the low, medium and high-dose groups was significantly lower than that in the control group (P < 0.01), and the 24-hour water content of feces was significantly lower than that in the control group (P < 0.05, 0.01). The time to the first red stool was significantly longer than that in the control group (P < 0.05), and the small intestinal propulsion rate was significantly lower than that in the control group (P < 0.05, 0.01). The pathological damage of the colon tissue was obvious, and the expressions of ChAT, c-kit and SCF proteins in the colon were significantly lower than those in the control group (P < 0.05, 0.01), while the expression of nNOS protein was significantly higher than that in the control group (P < 0.05, 0.01). On the 14th day of modeling, rats in the high-dose dexamethasone group died, while no deaths occurred in the other groups. Subsequently, the stability of the model was verified in the medium-dose group with better modeling effect. All rats survived throughout the 21-day experimental period, indicating that the medium dose had good safety. Conclusion Comprehensive assessment of both Yin deficiency indicators and constipation parameters demonstrates that the regimen of 0.175 mg·kg^-1 dexamethasone plus 10 mg·kg^-1 compound diphenoxylate with water restriction recapitulates the TCM pathogenesis of "insufficiency of Yin fluid leading to endogenous deficiency-heat".

R965

河北省中医药管理局科研计划项目（2024166）；现代中药新质生产力科技创新工程专项（24ZXZKSY00010）