TY - JOUR

T1 - GLP-2-mediated up-regulation of intestinal blood flow and glucose uptake is nitric oxide-dependent in TPN-fed piglets 1

AU - Guan, Xinfu

AU - Stoll, Barbara

AU - Lu, Xiaofeng

AU - Tappenden, Kelly A

AU - Holst, Jens Juul

AU - Hartmann, Bolette

AU - Burrin, Douglas G

PY - 2003/7

Y1 - 2003/7

N2 - BACKGROUND & AIMS: Our aim was to determine whether the intestinotrophic effects of GLP-2 are mediated by acute up-regulation of intestinal substrate utilization in TPN-fed piglets.METHODS: Twenty-four 12-day-old pigs, fitted with a portal flow probe and carotid, jugular and portal catheters, were fed by TPN for 7 days. On day 8, a group of pigs (n = 8) was infused intravenously with saline (control) for 4 hours and then with GLP-2 (500 pmol x kg(-1) x hour(-1), GLP-2) for 4 hours. (2)H-glucose and (13)C-phenylalanine were infused to estimate their kinetics and protein turnover. Another group (n = 8) received consecutive intravenous infusions of saline, GLP-2, and GLP-2 plus N(G)-Nitro-L-arginine methyl ester (L-NAME, 50 micromol x kg(-1) x hour(-1)) for 4 hours each.RESULTS: GLP-2 acutely increased portal-drained visceral (PDV) blood flow rate (+25%) and intestinal blood volume (+51%) in TPN-fed piglets. GLP-2 also increased intestinal constitutive nitric oxide synthase (NOS) activity and endothelial NOS protein abundance. GLP-2 acutely increased PDV glucose uptake (+90%) and net lactate production (+79%). Co-infusion of GLP-2 plus L-NAME did not increase either PDV blood flow rate or glucose uptake. GLP-2 increased PDV indispensable amino acid uptake by 220% and protein synthesis by 125%, but did not decrease protein breakdown or phenylalanine oxidation.CONCLUSIONS: We conclude that in TPN-fed neonatal pigs, GLP-2 acutely stimulates intestinal blood flow and glucose utilization, and this response is nitric oxide-dependent. These findings suggest that GLP-2 may play an important physiological role in the regulation of intestinal blood flow and that nitric oxide is involved in GLP-2 receptor function.

AB - BACKGROUND & AIMS: Our aim was to determine whether the intestinotrophic effects of GLP-2 are mediated by acute up-regulation of intestinal substrate utilization in TPN-fed piglets.METHODS: Twenty-four 12-day-old pigs, fitted with a portal flow probe and carotid, jugular and portal catheters, were fed by TPN for 7 days. On day 8, a group of pigs (n = 8) was infused intravenously with saline (control) for 4 hours and then with GLP-2 (500 pmol x kg(-1) x hour(-1), GLP-2) for 4 hours. (2)H-glucose and (13)C-phenylalanine were infused to estimate their kinetics and protein turnover. Another group (n = 8) received consecutive intravenous infusions of saline, GLP-2, and GLP-2 plus N(G)-Nitro-L-arginine methyl ester (L-NAME, 50 micromol x kg(-1) x hour(-1)) for 4 hours each.RESULTS: GLP-2 acutely increased portal-drained visceral (PDV) blood flow rate (+25%) and intestinal blood volume (+51%) in TPN-fed piglets. GLP-2 also increased intestinal constitutive nitric oxide synthase (NOS) activity and endothelial NOS protein abundance. GLP-2 acutely increased PDV glucose uptake (+90%) and net lactate production (+79%). Co-infusion of GLP-2 plus L-NAME did not increase either PDV blood flow rate or glucose uptake. GLP-2 increased PDV indispensable amino acid uptake by 220% and protein synthesis by 125%, but did not decrease protein breakdown or phenylalanine oxidation.CONCLUSIONS: We conclude that in TPN-fed neonatal pigs, GLP-2 acutely stimulates intestinal blood flow and glucose utilization, and this response is nitric oxide-dependent. These findings suggest that GLP-2 may play an important physiological role in the regulation of intestinal blood flow and that nitric oxide is involved in GLP-2 receptor function.

KW - Amino Acids

KW - Animals

KW - Animals, Newborn

KW - Dietary Proteins

KW - Female

KW - Glucagon-Like Peptide 2

KW - Glucagon-Like Peptides

KW - Glucose

KW - Intestines

KW - Liver Circulation

KW - Nitric Oxide

KW - Nitric Oxide Synthase

KW - Oxygen Consumption

KW - Pancreatic Hormones

KW - Parenteral Nutrition, Total

KW - Peptides

KW - Portal System

KW - Regional Blood Flow

KW - Sus scrofa

KW - Up-Regulation

M3 - Journal article

C2 - 12851879

VL - 125

SP - 136

EP - 147

JO - Gastroenterology

JF - Gastroenterology

SN - 0016-5085

IS - 1

ER -