Oral IGF-I enhances nutrient and electrolyte absorption in neonatal piglet intestine.
The effect of orally administered insulin-like growth factor-I (IGF-I) on small intestinal structure and function was studied in 5-day-old colostrum-deprived piglets. Human recombinant IGF-I (3.5 mg. kg(-1). day(-1)) or control vehicle was given orogastrically for 4 days. Body weights, jejunal and ileal mucosa wet and dry weights, and serum IGF-I levels were similar in the two groups. Small intestinal villus height and crypt depth and jejunal enterocyte microvillar dimensions were also similar between groups. Oral IGF-I produced higher rates of jejunal ion transport because of increased basal Na+ absorption. Short-circuit current responses to mucosal addition of D-glucose and L-alanine and net transepithelial absorption of 3-O-methylglucose were increased by IGF-I. Carrier-mediated uptake of D-glucose per milligram in everted jejunal sleeves was greater in IGF-I-treated piglets because of a significantly greater maximal rate of uptake. We conclude that rates of net Na+ and Na+-dependent nutrient absorption are enhanced in piglets treated with oral IGF-I, and this effect is independent of changes in mucosal mass or surface area.
Alexander
A N
AN
Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin 53706, USA.
Carey
H V
HV
D000284:Administration, Oral; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000831:Animals, Newborn / Q000033:anatomy & histology / Q000097:blood; D001835:Body Weight; D004573:Electrolytes / Q000378:metabolism*; D006801:Humans; D007082:Ileum / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000032:analysis / Q000494:pharmacology*; D007408:Intestinal Absorption / Q000187:drug effects*; D007413:Intestinal Mucosa / Q000033:anatomy & histology; D017136:Ion Transport; D007583:Jejunum / Q000378:metabolism; D008871:Microvilli / Q000648:ultrastructure; D011994:Recombinant Proteins; D013552:Swine
D004573:Electrolytes; D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I