Oxyntomodulin stimulates intestinal glucose uptake in rats.
OBJECTIVE
Enteroglucagon peptides have long been proposed as mediators of intestinal adaptation, including mucosal growth and nutrient absorptive capacity. The hypothesis that infusions of oxyntomodulin, a bioactive form of enteroglucagon, would stimulate glucose and amino acid uptake was tested and its effects were compared with those of glucagon.


METHODS
Rats were infused intravenously via minipumps with either saline, rat oxyntomodulin (0.47 nmol x kg(-1) x h[-1]), or glucagon (0.88 nmol x kg(-1) x h[-1]) for 7 days, and plasma hormone levels were measured. At death, intestinal dimensions and brush border uptake of D-glucose and L-proline were measured using an in vitro everted sleeve technique.


RESULTS
Plasma enteroglucagon and glucagon levels were increased 4- and 12-fold, respectively, but there were no effects on food intake, body weight, or intestinal dimensions. In contrast, oxyntomodulin and glucagon significantly stimulated total intestinal glucose uptake capacity by 44% and 53%, respectively, over controls. Oxyntomodulin most potently enhanced glucose uptake in the ileum (215%), whereas glucagon's greatest effect was in the jejunum (63%-85%). However, neither peptide affected proline uptake.


CONCLUSIONS
These results support a new, specific action for oxyntomodulin in intestinal adaptation as a glucose uptake stimulator and confirm glucagon's role as a regulator of glucose uptake.
Collie
N L
NL
Department of Biological Sciences and Institute for Biotechnology, Texas Tech University, Lubbock 79409-3131, USA.
Zhu
Z
Z
Jordan
S
S
Reeve
J R
JR
D000818:Animals; D004763:Glucagon-Like Peptides / Q000494:pharmacology*; D005947:Glucose / Q000378:metabolism*; D007422:Intestines / Q000187:drug effects*; D008297:Male; D053772:Oxyntomodulin; D051381:Rats; D017207:Rats, Sprague-Dawley
D053772:Oxyntomodulin; D004763:Glucagon-Like Peptides; D005947:Glucose