IGF alters jejunal glucose transporter expression and serum glucose levels in immature rats. Am J Physiol Regul Integr Comp Physiol 2002 Dec;283(6):R1450-60
Date
10/22/2002Pubmed ID
12388463DOI
10.1152/ajpregu.00172.2002Scopus ID
2-s2.0-0036889473 (requires institutional sign-in at Scopus site) 31 CitationsAbstract
Milk-borne insulin-like growth factors (IGFs) enhance nutrient absorption in the immature intestine, which is characterized by low levels of glucose oxidation. We therefore hypothesized that feeding a rat milk substitute (RMS) devoid of growth factors to rat pups would lower serum glucose levels relative to dam-fed control rats and that supplementation of RMS with physiological doses of either IGF-I or IGF-II would normalize serum glucose levels via increased jejunal glucose transporter 2 (GLUT2) and high-affinity Na(+)-glucose cotransporter (SGLT1) expression. We found lower serum glucose concentrations in RMS-fed pups; in contrast, serum glucose levels in the IGF-supplemented pups were similar to those of dam-fed controls. RT-PCR and laser scanning confocal microscopy similarly demonstrated that IGF supplementation increased expression of jejunal glucose transporters. Further experiments demonstrated that IGF supplementation altered mRNA levels of key mitochondrial enzymes without altering jejunal lactase activity. We conclude that IGF-I and IGF-II supplementation increases serum glucose levels in the immature rat pup fed artificial formula and alters gene expression of the jejunal glucose transporters.
Author List
Lane RH, Dvorak B, MacLennan NK, Dvorakova K, Halpern MD, Pham TD, Philipps AFMESH terms used to index this publication - Major topics in bold
Animal FeedAnimals
Animals, Suckling
Blood Glucose
Body Weight
Diet
Female
Gene Expression Regulation
Glucose Transporter Type 1
Glucose Transporter Type 2
Jejunum
Lactase
Male
Membrane Glycoproteins
Milk
Monosaccharide Transport Proteins
Polymerase Chain Reaction
RNA, Messenger
Rats
Rats, Sprague-Dawley
Sodium-Glucose Transporter 1
Somatomedins
beta-Galactosidase
