Study on the mechanism of hedysarum polybotrys polysacchcaide improving small intestinal motility in spleen qi deficiency DGP rats through SCFAs-GPCRs
Objective:To observe the effect of hedysarum polybotrys polysacchcaide(HPS)on short chain fatty acids(SCFAs)-G protein-coupled receptors(GPCRs)in rats with spleen qi deficiency type diabetes gastroparesis(DGP),and to explore the possible mechanism of HPS in improving intestinal motility in rats with spleen qi deficiency type DGP.Methods:A total of 72 SPF grade Wistar male rats were randomly divided into a blank group of 10 rats and model group of 62 rats.The modeling group used a multifactor modeling method combined with low dose multiple intraperitoneal injections of STZ and irregular feeding with high sugar and high fat feed to prepare a spleen qi deficiency type DGP rat model.The modeling rats were randomly divided into a model group,a positive control group(0.09 g·kg-1·d-1 Metformin Tablets),and high,medium,and low dose HPS groups(0.2,0.1,0.05 g·kg-1·d-1),the blank group and model group were given equal doses of pure water by gavage once a day for 8 consecutive weeks.The random blood glucose and small intestine propulsion rate of rats were observed.The pathological and morphological changes of the small intestine under light microscopy were observed,ELISA method was used to detect the levels of GLP-1,PYY and 5-HT in serum,while RT-PCR and Western Blot were used to detect the mRNA and protein expression levels of GPR41,GPR43 and GPR109A in small intestine tissue;gas chromatography was used to determine the content of SCFAs in feces.Results:Compared with the blank group,the model group showed an increase in random blood glucose,PYY and GLP-1 levels(P<0.01,P<0.05),while the small intestine propulsion rate and 5-HT content decreased(P<0.01);Under light microscopy,the normal structure of small intestine tissue was destroyed,intestinal villi disappeared,intestinal glands degenerated and necrotic,and the content of acetic acid,butyric acid,propionic acid,GPR41,GPR43,GPR109A mRNA and protein expression decreased(P<0.01,P<0.05).After 8 weeks of medication,compared with the model group,the positive control group and the high-dose HPS group randomly showed a decrease in blood glucose,PYY,and GLP-1 levels(P<0.01),while the small intestine propulsion rate and 5-HT content increased(P<0.01);under the light microscope,the condition of each medication group improved,with the HPS high and medium dose groups showing significant improvement;the content of acetic acid,propionic acid,and butyric acid,as well as the mRNA and protein expression of GPR41,GPR43 and GPR109A increased(P<0.01,P<0.05).Compared with the positive control group,the expression of GPR41,GPR43 and GPR109A mRNA and protein in low-dose HPS small intestine tissue decreased(P<0.01,P<0.05).Conclusion:The mechanism of HPS improving small intestinal motility in spleen deficiency type DGP rats may be related to increasing the content of SCFAs-GPCRs and improving intestinal homeostasis.
Diabetic gastroparesis(DGP)Hedysarum polybotrys polysacchcaideG protein coupled receptors(GPCRs)Short chain fatty acids(SCFAs)Intestinal motilityMechanismAnimal model