辣椒素对水浸-束缚应激大鼠胃动力的作用及机制研究

Effect and mechanism of capsaicin on gastric motility in water immersion restraint stress rats

目的探讨辣椒素(capsaicin,CAP)对水浸-束缚应激(water immersion restraint stress,WIRS)大鼠胃动力的作用及机制。方法雄性SD大鼠30只,随机分为3组:正常对照组、WIRS模型组、CAP干预组。其中正常对照组自由摄食进水;WIRS模型组每日WIRS 1 h后自由摄食进水;CAP干预组每日WIRS 1 h后喂食CAP饲料。4周后所有大鼠给予酚红溶液灌胃后麻醉处死,测定胃酚红排空率;采用ELISA法检测血浆胃动素(motilin,MTL)水平;采用免疫组化方法检测胃窦辣椒素受体(transient receptor potential vanilloid1,TRPV1)、P物质(substance P,SP)的表达;用RT-PCR方法检测c-kit m RNA、SCF m RNA的转录水平。结果大鼠胃酚红排空率:WIRS模型组胃酚红排空率显著低于其余两组(P<0.05);正常对照组胃酚红排空率与CAP干预组相比,差异无统计学意义(P>0.05)。血浆MTL水平:WIRS模型组血浆MTL水平显著低于其余两组(P<0.05);正常对照组血浆MTL水平显著低于CAP干预组(P<0.05)。免疫组化结果:大鼠胃窦组织TRPV1表达积分:CAP干预组TRPV1表达水平显著高于其余两组(P<0.05);正常对照组TRPV1表达水平与WIRS模型组相比,差异无统计学意义(P>0.05)。大鼠胃窦组织SP表达积分:WIRS模型组SP表达水平显著低于其余两组(P<0.05);正常对照组SP表达水平显著低于CAP干预组(P<0.05)。RT-PCR方法检测结果:大鼠胃窦组织c-kit m RNA表达结果:WIRS模型组c-kit m RNA转录水平显著低于正常对照组(P<0.05);正常对照组、WIRS模型组c-kit m RNA转录水平与CAP干预组相比,差异无统计学意义(P>0.05)。大鼠胃窦组织SCF m RNA表达结果:WIRS模型组SCF m RNA转录水平显著低于其余两组(P<0.05);正常对照组SCF m RNA转录水平显著低于CAP干预组(P<0.05)。结论 CAP可能对WIRS大鼠胃动力具有改善作用,其机制可能与CAP调节TRPV1、SP的表达及MTL的释放有关,是否与Cajal间质细胞相关尚不明确。

Objective To investigate the effect and mechanism of capsaicin （CAP） on gastric motility in water im- mersion restraint stress （WIRS） rats. Methods Thirty male SD rats were randomly divided into 3 groups： normal con- trol group, WIRS model group and CAP group. Rats in normal control group were freely accessed to food and water. Rats in WIRS model group were freely accessed to food and water after the stress. Rats in CAP group were fed the CAP after the stress. After 4 weeks, all the rats were lavaged with phenol red solution, then the rats were killed. The gastric emptying rate of phenol red was tested, the plasma MTL level was detected by ELISA method, the expressions of TR- PV1, SP were detected by immunohistochemical method, and the transcriptional levels of c-kit mRNA, and SCF mRNA were detected by RT-PCR method. Results The gastric emptying rate of phenol red ： the gastric emptying rate in WIRS model group was significantly lower than that in other two groups （P 〈 0.05） ; the gastric emptying rate between normal control group and CAP group had no significant difference （P 〉 0.05）. The plasma MTL results： the level of plasma MTL in WIRS model group was significantly lower than that in other two group （P 〈 0.05） ; the level of plasma MTL in normal control group was significantly lower than that in the CAP group （P 〈 0.05 ）. Immunohistochemistry detection re- sults ： the expression of TRPV1 in the CAP group was significantly higher than that in other two groups （P 〈 0.05） ; but there was no significant difference between normal control group and WIRS model group （P 〉 0.05）. The expression of SP in WIRS model group was significantly lower than that in other two groups （P 〈 0.05） ; the expression of SP in normal control group was significantly lower than that in the CAP group （P 〈 0.05 ）. Results of RT-PCR method ： the expres- sion of c-kit mRNA in WIRS model group was significantly lower than that in normal control group （P 〈 0.05 ） ; but there were no significant differences between normal control group and CAP group or WIRS model group and CAP group （P〉0. （P〈0. （P〈O. motility tionship 05）. The expression of SCF mRNA in WIRS model group was significantly lower than that in other two groups 05） ; the expression of SCF mRNA in normal control group was significantly lower than that in the CAP group 05）. Conclusion CAP may improve the gastric emptying rate of WIRS rats, the mechanism of CAP on gastric may be related with regulating the expressions of TRPV1 and SP, the release of MTL, but has no obvious rela- with interstitial cells of Cajal.