Ghrelin对大鼠胃排空及食管下括约肌压力的影响及其机制

The effect of Ghrelin on gastric emptying and lower esophageal sphincter pressure in rats and its mechanism

目的:观察胃促生长素(Ghrelin)对大鼠胃排空及食管下括约肌(LES)压力的影响,同时测定血浆中胃动素和P物质水平的变化,探讨Ghrelin对胃排空及LES压力的影响及相关机制。方法:Wistar大鼠接受不同剂量Ghrelin(0.5、1.0、1.5、2.0、2.5 nmol/kg)腹腔注射后,测定胃排空率;Wistar大鼠接受1.5 nmol/kg Ghrelin腹腔注射后进行LES压力测定,放射免疫法测定血浆中胃动素及P物质浓度。结果:腹腔注射Ghrelin后大鼠胃排空率为38.24%±7.15%,与对照组(27.03%±2.91%)比明显加快(P<0.01),同时该效应与腹腔注射Ghrelin的量呈量效关系,腹腔注射Ghrelin后大鼠LES压力[(19.57±3.26)mmHg]与对照组[(13.78±2.29)mmHg]比明显增加(P<0.05),提示Ghrelin能增加大鼠LES压力;腹腔注射Ghrelin后大鼠血浆胃动素浓度[(217.28±25.38)ng/L]与对照组[(190.02±18.18)ng/L]比明显增加(P<0.05),提示胃动素可能参与Ghrelin对大鼠食管下括约肌压力的调节。结论:中、高剂量Ghrelin腹腔注射,能明显加快健康大鼠的胃排空效应,Ghrelin能明显增加LES压力,胃动素可能参与Ghrelin对大鼠LES压力的调节。

Objective:To investigate the effects of Ghrelin on gastric emptying and lower esophageal sphincter pressure(LESP),expressions of Motilin and Substance P(SP)in plasma,and to explore the mechanism of Ghrelin on gastric emptying and LESP.Methods:After Wistar rats were intraperitioneally injected with different doses of Ghrelin(0.5,1.0,1.5,2.0,2.5 nmol/kg),gastric emptying rate was measured;after intraperitoneal injecion of 1.5 nmol/kg,LESP was measured,and plasma Motilin and SP concentrations were determined by radioimmunoassay.Results:After intraperitoneal injection of Ghrelin,gastric emptying rate was significantly faster than controls[(38.24±7.15)%vs.(27.03±2.91)%],and the accelerated gastric emptying had a significant dose-response relationship with Ghrelin.After intraperitoneal injection of Ghrelin,LESP[(19.57±3.26)mmHg]in rats was significantly increased compared with the control group[(13.78±2.29)mmHg](P<0.05),suggested that Ghrelin could increase the LESP in rats.After intraperitoneal injection of Ghrelin,plasma Motilin concentration[(217.28±25.38)ng/L]in rats was significantly increased compared with the control group[(190.02±18.18)ng/L](P<0.05),suggesting that Motilin may be involved in the LESP regulation in rats.Conclusion:Intraperitoneal injection of Ghrelin can accelerate gastric emptying in rats,Ghrelin may increase the pressure of the lower esophageal sphincter in rats,and Motilin may be involved in the LESP regulation.