Effect of Ghrelin on PepT1 of the small intestinal epithelium in rats with sepsis

Abstract

Objective To investigate the effect of Ghrelin on expression and function of PepT1 of the small intestinal epithelium in rats with sepsis.Methods Eighty male Sprague-Dawley (SD) rats were divided into four groups by random number table:normal group,sham operation group,sepsis group and Ghrelin group,with 20 rats in each group.The model of sepsis was reproduced with cecal ligation and puncture (CLP).After the procedure Ghrelin was injected via vein in the Ghrelin group.Ten rats in each group were used to study the intestinal pathology.In addition,real time polymerase chain reaction (PCR) and Western blotting were used to detect PepT1 mRNA expression and PepT1 protein expression levels respectively in each group.The uptake of PepT1 by small intestinal epithelial cells was also measured.Seven-day survival was observed in other 10 rats of groups.Results Compared with normal and sham operation groups,the damage to the small intestine mucosa was more serious in sepsis group,and the PepT1 mRNA expression (21.43 ± 1.37 vs.23.29 ± 1.24,23.23 ± 1.48),the PepT1 protein expression (7832.55 ± 699.74 vs.13 584.74 ± 360.66,13 152.51 ± 605.72) and the uptake of PepT1 (60 minutes:3.23 ± 0.30 vs.6.67 ± 0.51,6.52 ± 0.47) in the sepsis group were significantly lowered (all P＜0.05).Compared with the sepsis group,less damage to the small intestine mucosa was found in the Ghrelin group,and the survival rate of rats (40％ vs.20％),PepT1 mRNA expression (22.73 ± 1.16 vs.21.43 ± 1.37),PepT1 protein expression (10 506.26 ± 850.59 vs.7832.55 ± 699.74) and the uptake of PepT1 (60 minutes:4.83 ± 0.32 vs.3.23 ± 0.30) were significantly improved in the Ghrelin group (all P＜ 0.05).There was no difference in various indicators between sham operation and normal groups.Conclusions The PepT1 mRNA and protein expression of the small intestinal epithelium in septic rats were significantly decreased,which affected the physiological function of PepT1.Ghrelin could marked up-regulate the PepT1 mRNA and protein expression and uptake of PepT1 of small intestinal epithelial cells. Key words: Sepsis; Ghrelin; PepT1 ; Cecal ligation and puncture