Intestinal maturation induced by spermine in young animals

In suckling mts, it has been established that oral administration of spermi ne, a dietary polyamine, at appropriate doses, induces all the modification s in the digestive tract that occur at weaning, namely, (a) in the intestin e: variations in the specific activities of disaccharidases and peptidases, gene expression, the level of receptors to polymeric immunoglobulins (RPIs ), tissue histology, and the intestinal permeability to macromolecules; (b) maturation of the intestinal immunological system, an observation confirme d in mice; (c) an increase in the specific activity of enzymes contained in the pancreas; (d) a change in the growth rate and biochemical properties o f the liver, e.g., in the synthesis of RPIs. The mechanism of spermine acti on is partly understood. In the intestine, two phases of events have been r ecorded. The first phase consists of the desquamation of the epithelium res ulting from an activation of apoptosis, probably induced by the entrance of spermine into the enterocytes. The second phase concerns a hormonal cascad e in which adrenocorticotrophic hormone, cytokines, bombesin and corticoste rone intervene. A general hypothesis taking into account all the results ob tained until now is presented as well as other observations recorded on the effect of exogenous spermine on the intestinal maturation of vertebrates o ther than the rat. (C) 2000 Elsevier Science B.V. All rights reserved.