title: Intraportal infusion of ghrelin could inhibit glucose-stimulated GLP-1 secretion by enteric neural net in Wistar rat.
abstract: As a regulator of food intake and energy metabolism, the role of ghrelin in glucose metabolism is still not fully understood. In this study, we determined the in vivo effect of ghrelin on incretin effect. We demonstrated that ghrelin inhibited the glucose-stimulated release of glucagon-like peptide-1 (GLP-1) when infused into the portal vein of Wistar rat. Hepatic vagotomy diminished the inhibitory effect of ghrelin on glucose-stimulated GLP-1 secretion. In addition, phentolamine, a nonselective α receptor antagonist, could recover the decrease of GLP-1 release induced by ghrelin infusion. Pralmorelin (an artificial growth hormone release peptide) infusion into the portal vein could also inhibit the glucose-stimulated release of GLP-1. And growth hormone secretagogue receptor antagonist, [D-lys3]-GHRP-6, infusion showed comparable increases of glucose stimulated GLP-1 release compared to ghrelin infusion into the portal vein. The data showed that intraportal infusion of ghrelin exerted an inhibitory effect on GLP-1 secretion through growth hormone secretagogue receptor 1α (GHS1α receptor), which indicated that the downregulation of ghrelin secretion after food intake was necessary for incretin effect. Furthermore, our results suggested that the enteric neural net involved hepatic vagal nerve and sympathetic nerve mediated inhibition effect of ghrelin on incretin effect.
authors.affiliation: Department of Endocrinology and Metabolism, The 4th Hospital Affiliated to Harbin Medical University, No. 37, Yiyuan Street, Harbin 150000, China.
authors.forename: Xiyao
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Endocrinology and Metabolism, The 2nd Hospital Affiliated to Harbin Medical University, No. 246, Xuefu Road, Harbin 150080, China.
authors.forename: Wensong
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Endocrinology and Metabolism, The 2nd Hospital Affiliated to Harbin Medical University, No. 246, Xuefu Road, Harbin 150080, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.affiliation: Department of Laboratory Medicine, The 2nd Hospital Affiliated to Harbin Medical University, No. 246, Xuefu Road, Harbin 150080, China.
authors.forename: Manli
authors.initials: M
authors.lastname: Chang
authors.affiliation: Department of Endocrinology and Metabolism, The 2nd Hospital Affiliated to Harbin Medical University, No. 246, Xuefu Road, Harbin 150080, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Huang
authors.affiliation: Department of Endocrinology and Metabolism, The 2nd Hospital Affiliated to Harbin Medical University, No. 246, Xuefu Road, Harbin 150080, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Endocrinology and Metabolism, The 2nd Hospital Affiliated to Harbin Medical University, No. 246, Xuefu Road, Harbin 150080, China.
authors.forename: Can
authors.initials: C
authors.lastname: Cui
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D017615:Enteric Nervous System / Q000187:drug effects / Q000378:metabolism*; D054439:Ghrelin / Q000008:administration & dosage*; D052216:Glucagon-Like Peptide 1 / Q000378:metabolism*; D005947:Glucose / Q000008:administration & dosage*; D054795:Incretins / Q000008:administration & dosage*; D007262:Infusions, Intravenous; D007328:Insulin / Q000097:blood*; D008297:Male; D011169:Portal Vein; D051381:Rats; D017208:Rats, Wistar
chemical_list: D001786:Blood Glucose; D054439:Ghrelin; D054795:Incretins; D007328:Insulin; D052216:Glucagon-Like Peptide 1; D005947:Glucose