基于TRPM8通路探讨晕清降压方治疗肥胖型代谢性高血压的机制

Mechanism of Yunqing Jiangya decoction in the treatment of obese metabolic hypertension based on on TRPM8 pathway

目的 观察晕清降压方对肥胖型代谢性高血压大鼠的干预作用及对瞬时受体电位8(TRPM8)信号通路的影响,探讨其作用机制。方法 选择SPF级健康雄性大鼠40只,从中随机选取8只大鼠给予普食喂养+蒸馏水灌胃作为空白组,剩余32只大鼠运用高盐高脂饲料饮食诱导+小剂量链脲佐菌素(STZ)注射+慢性环境刺激法建立痰瘀互结证肥胖型代谢性高血压模型。将24只造模成功大鼠随机分为模型组、缬沙坦组和晕清降压方组,每组8只。监测各组大鼠灌胃前和灌胃4 d、8 d、12 d、14 d的血压,比较各组大鼠灌胃结束后体重、Lee’s指数、血脂、血糖及血液流变学指标,HE染色观察肠系膜动脉组织病理形态,免疫荧光观察肠系膜动脉血管平滑肌细胞表达情况,免疫组化观察肠系膜动脉中TRPM8蛋白表达情况,Western blot法检测肠系膜动脉中TRPM8蛋白表达情况。结果 灌胃4 d、8 d、12 d、14 d,晕清降压方组与缬沙坦组大鼠的收缩压及舒张压均明显低于同期模型组(P均<0.05),晕清降压方组与缬沙坦组大鼠各时间点收缩压及舒张压比较差异均无统计学意义(P均>0.05)。晕清降压方组大鼠的体重、Lee’s指数明显低于模型组及缬沙坦组(P均<0.05);晕清降压方组和缬沙坦组大鼠血清TC、TG、LDL-C、血糖、全血低切黏度、全血中切黏度、全血高切黏度、血浆黏度均明显低于模型组(P均<0.05),血清HDL-C水平均明显高于模型组(P均<0.05),晕清降压方组和缬沙坦组各指标比较差异均无统计学意义(P均>0.05)。晕清降压方组及缬沙坦组大鼠肠系膜动脉的损伤程度较模型组轻;晕清降压方组及缬沙坦组大鼠肠系膜动脉中平滑肌细胞阳性表达率均明显高于空白组和模型组(P均<0.05);晕清降压方组大鼠肠系膜动脉中TRPM8蛋白光密度值和蛋白相对表达量均明显高于其他组(P均<0.05)。结论 晕清降压方具有良好的降压、降脂、改善血液流变学作用,该方可能通过调控TRPM8通路调节血管平滑肌细胞收缩来发挥降压作用。

Objective It is to observe the interventional effects of Yunqing Jiangya decotion on obese metabolic hypertensive rats and its effect on transient receptor potential melastatin 8(TRPM8)signal pathway,and to explore its mechanism of action.Methods Forty healthy male rats of SPF grade were selected,in which 8 rats were randomly selected as a blank group and given plain food feeding plus distilled water by gavage,the remaining 32 rats were induced with a high-salt,high-fat diet plus low-dose streptozotocin(STZ)injection and chronic environmental stimulation to establish obese metabolic hypertension models with syndrome of phlegm and stasis binding.24 successfully moulded rats were randomly divided into model group,valsartan group and Yunqing Jiangya decotion group,with 8 rats in each group.The blood pressure of the rats in each group was monitored before and at 4 d,8 d,12 d and 14 d after gavage,and their body weight,Lee’s index,blood lipids,blood glucose and blood rheological parameters were compared among the groups at the end of treatment.The histopathological pattern of mesenteric arteries was observed by HE staining,the expression of smooth muscle cells in mesenteric arteries was observed by immunofluorescence,the positive expression of TRPM8 protein in mesenteric arteries was observed by immunohistochemistry,and the relative expression of TRPM8 protein in mesenteric arteries was observed by Western blot.Results At 4 d,8 d,12 d and 14 d of gavage,the systolic and diastolic blood pressure of the rats in the Yunqing Jiangya decotion group and the valsartan group were significantly lower than those in the model group at the same time(all P<0.05),there was no statistically significant difference in the systolic and diastolic blood pressure of the rats between the Yunqing Jiangya decotion group and the valsartan group at all time points(all P>0.05).The body weight and Lee’s index of rats in the Yunqing Jiangya decotion group were significantly lower than those in the model group and the valsartan group(all P<0.05),the levels of serum TC,TG,LDL-C,blood glucose,whole blood low-cut viscosity,whole blood mid-cut viscosity,whole blood high-cut viscosity and plasma viscosity were all significantly lower in the rats of the Yunqing Jiangya decotion and valsartan groups than those in the model group(all P<0.05),while the levels of serum HDL-C were significantly higher than that in the model group(all P<0.05),there was no statistically significant difference in the indicators between the Yunqing Jiangya decotion group and the valsartan group(all P>0.05).The damage to mesenteric arteries in the rats of the Yunqing Jiangya decotion group and the valsartan group was less serious than that in the model group.The positive expression rates of smooth muscle cells in mesenteric arteries of rats in both the Yunqing Jiangya decotion group and the valsartan group were significantly higher than those of the blank group and the model group(both P<0.05).The optical density value and relative protein expression of TRPM8 protein in the mesenteric arteries of rats in the Yunqing Jiangya decotion group was significantly higher than that of other groups(P<0.05).Conclusion Yunqing Jiangya decotion has good hypotensive,hypolipidemic and blood rheology improving effects,and this formula may exert its antihypertensive effect by modulating the TRPM8 pathway to regulate vascular smooth muscle cell contraction.