Dexamethasone and GLP-2 given to lactating rat dams influence glucose uptake in suckling and postweanling offspring.
BACKGROUND
Glucagon-like peptide-2 (GLP-2) enhances intestinal absorption in adult animals. Glucocorticosteroids accelerate the ontogeny of the intestine and increase sugar uptake in adult animals. Modifying the maternal diet during lactation alters nutrient uptake in the offspring. The authors hypothesized that GLP-2 and dexamethasone, when administrated to lactating rat dams, enhance sugar uptake in the suckling and postweanling offspring.


METHODS
Rat dams were treated during lactation with GLP-2 (0.1 microg/g/day subcutaneously [SC], twice daily), dexamethasone (0.128 microg/g/day SC, once daily), GLP-2 + dexamethasone (same doses), or placebo. The suckling offspring were sacrificed at 19-21 days of age, and the postweanlings were sacrificed 4 weeks later. Intestinal glucose and fructose uptake was assessed using an in vitro ring technique.


RESULTS
GLP-2 and dexamethasone resulted in lower body weights, and dexamethasone caused intestinal atrophy in sucklings. The jejunal atrophy in sucklings given dexamethasone was prevented by GLP-2 + dexamethasone. In sucklings, the maximal transport rate and the Michaelis affinity constant for ileal glucose uptake were both increased by GLP-2 and GLP-2 + dexamethasone. In contrast, in postweanlings, the maximal transport rate for jejunal glucose uptake was reduced by dexamethasone and GLP-2, as was ileal fructose uptake.


CONCLUSIONS
Treating lactating rat dams with GLP-2 or dexamethasone enhances glucose uptake in sucklings, but the late effect is a reduction in glucose and fructose absorption in postweanlings. The nutritional significance of these findings remains to be established.
Drozdowski
Laurie
L
Division of Gastroenterology, University of Alberta, Edmonton, Alberta, Canada.
Iordache
Claudiu
C
Clandinin
M Tom
MT
Wild
Gary
G
Todd
Zoe
Z
Thomson
Alan B R
AB
D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D000833:Animals, Suckling; D016022:Case-Control Studies; D003907:Dexamethasone / Q000494:pharmacology*; D005260:Female; D053767:Glucagon-Like Peptide 2 / Q000494:pharmacology*; D005938:Glucocorticoids / Q000494:pharmacology*; D005947:Glucose / Q000493:pharmacokinetics*; D007408:Intestinal Absorption / Q000187:drug effects*; D007583:Jejunum / Q000187:drug effects / Q000473:pathology; D011247:Pregnancy; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D014886:Weaning
D053767:Glucagon-Like Peptide 2; D005938:Glucocorticoids; D003907:Dexamethasone; D005947:Glucose