Maturation of jejunoileal gradients in rat intestine: the role of intraluminal nutrients.
Jejunoileal gradients of intestinal function are thought to be established during the third week of life in the rat when postnatal intestinal maturation occurs. In order to investigate the normal development of jejunoileal gradients and whether either the absence of intraluminal nutrients or the form in which they are provided affected the development of jejunoileal gradients, gradients for mucosal DNA, protein, lactase and sucrase were studied in suckling rats undergoing normal weaning and compared to gradients in rats receiving no intraluminal nutrients or rats receiving nutrients in elemental form. In suckling animals, preexisting jejunoileal gradients for DNA and protein persisted through the weaning period, gradients for lactase formed by rapid decline of ileal function and sucrase gradients formed by rapid increase in jejunal activities. Intraluminal nutrients in elemental form resulted in the formation of jejunoileal gradients similar to those in intestines of normally weaned rats. The lack of intraluminal nutrients resulted in no qualitative differences in the expression of jejunoileal gradients for sucrase, but provision of elemental nutrients resulted in increased jejunoileal differences for this enzyme. The lack of intraluminal nutrients resulted in no gradients for DNA, less pronounced jejunoileal differences for protein and delayed maturational decline of ileal lactase which prevented development of jejunoileal gradients for the enzyme. These studies indicate that the formation of jejunoileal gradients in the maturing rat intestine for the parameters investigated require intraluminal nutrients regardless of the form in which they are provided for their normal expression.
Castillo
R O
RO
Department of Pediatrics, Stanford University Medical Center, Calif.
Feng
J J
JJ
Stevenson
D K
DK
Kwong
L K
LK
D000375:Aging / Q000378:metabolism; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000833:Animals, Suckling; D004247:DNA / Q000378:metabolism; D007082:Ileum / Q000254:growth & development* / Q000378:metabolism; D007413:Intestinal Mucosa / Q000254:growth & development / Q000378:metabolism; D007583:Jejunum / Q000254:growth & development* / Q000378:metabolism; D043322:Lactase; D011506:Proteins / Q000378:metabolism; D051381:Rats; D013393:Sucrase / Q000378:metabolism; D001616:beta-Galactosidase / Q000378:metabolism
D011506:Proteins; D004247:DNA; D043322:Lactase; D001616:beta-Galactosidase; D013393:Sucrase