Rat Milk and Dietary Long Arginine3 Insulin-Like Growth Factor I Promote Intestinal Growth of Newborn Rat Pups

    loading  Checking for direct PDF access through Ovid

Abstract

ABSTRACT

Newborn rat pups were artificially reared by the pup in cup (PIC) method to determine whether dietary long arginine3. IGF-I (long R3 IGF-I), and IGF-I analog with high receptor affinity and low IGF binding protein (IGFBP) affinity, had efficacy on intestinal growth. IGF effects are mediated by IGFBP and receptor interactions, hence dietary-induced changes in intestinal IGF-II receptor patterns and IGFBP-3 message levels were investigated. Intestinal micrographs of pups fed rat milk replacer (RMR) for 3 d showed flattened villi with low cell counts and appeared similar to newborn intestines. Mother-fed (MF) controls and long R3 IGF-I-fed pups showed increased villi height and cell counts when compared with RMR pups, with long R3 IGF-I fed pups showing the greatest increase. At birth IGF-II-specific binding was not uniform in the intestine; specific binding was higher in the proximal intestinal section than in the distal intestinal section. However, after 3 d of MF treatment, specific binding had reversed and the distal section showed higher IGF-II-specific binding. Three days of RMR feeding did not change IGF-II-specific binding from that of the newborn pup. An IGFBP-3 message was identified in intestinal epithelium by in situ hybridization. Northern analysis of IGFBP-3 message showed a decline over time, but the change was not influenced by dietary treatments. In summary, milk-borne growth factors have the potential to affect intestinal growth within 3 d of treatment.

Related Topics

    loading  Loading Related Articles