Whey protein potentiates the intestinotrophic action of glucagon-like peptide-2 in parenterally fed rats.
Glucagon-like peptide-2 (GLP-2) is a nutrient-regulated intestinotrophic hormone derived from proglucagon in the distal intestine. Enteral nutrients (EN) potentiate the action of GLP-2 to reverse parenteral nutrition (PN)-induced mucosal hypoplasia. The objective was to determine what enteral protein component, casein, soy, or whey protein, potentiates the intestinal growth response to GLP-2 in rats with PN-induced mucosal hypoplasia. Rats received PN and continuous intravenous infusion of GLP-2 (100 microg/kg/day) for 7 days. Six EN groups received PN+GLP-2 for days 1-3 and partial PN+GLP-2 plus EN for days 4-7. EN was provided by ad libitum intake of a semielemental liquid diet with different protein sources: casein, hydrolyzed soy, whey protein concentrate (WPC), and hydrolyzed WPC+casein. Controls received PN+GLP-2 alone. EN induced significantly greater jejunal sucrase activity and gain of body weight, and improved feed efficiency compared with PN+GLP-2 alone. EN induced greater ileal proglucagon expression, increased plasma concentration of bioactive GLP-2 by 35%, and reduced plasma dipeptidyl peptidase IV (DPP-IV) activity compared with PN+GLP-2 alone, P < 0.05. However, only whey protein, and not casein or soy, potentiated the ability of GLP-2 to reverse PN-induced mucosal hypoplasia and further increase ileal villus height, crypt depth, and mucosa cellularity compared with PN+GLP-2 alone, P < 0.05. The ability of whey protein to induce greater mucosal surface area was associated with decreased DPP-IV activity in ileum and colon compared with casein, soy, or PN+GLP-2 alone, P < 0.05. In conclusion, whey protein potentiates the action of GLP-2 to reverse PN-induced mucosal hypoplasia in association with decreased intestinal DPP-IV activity.
Liu
Xiaowen
X
Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Murali
Sangita G
SG
Holst
Jens J
JJ
Ney
Denise M
DM
D000818:Animals; D001835:Body Weight / Q000502:physiology; D018819:Dipeptidyl Peptidase 4 / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000502:physiology; D053767:Glucagon-Like Peptide 2 / Q000097:blood / Q000494:pharmacology*; D007413:Intestinal Mucosa / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D007422:Intestines / Q000187:drug effects* / Q000254:growth & development*; D008297:Male; D008894:Milk Proteins / Q000494:pharmacology*; D023421:Models, Animal; D010288:Parenteral Nutrition; D052336:Proglucagon / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013393:Sucrase / Q000378:metabolism; D000067816:Whey Proteins
D053767:Glucagon-Like Peptide 2; D008894:Milk Proteins; D000067816:Whey Proteins; D052336:Proglucagon; D013393:Sucrase; D018819:Dipeptidyl Peptidase 4