Effects of Parenteral and Enteral Nutrition on Postnatal Development of the Small Intestine and Pancreas in the Rabbit

Abstract

Although TPN is used frequently in young infants, little information is available regarding its effect on postnatal development of the gut. The effect of total parenteral nutrition (TPN) and intragastric (IG) alimentation on ontogeny of the small intestine was examined in infant rabbits starting at 10–12 days. Animals were killed at 17–19 days. Body weight, organ weight and weight of segments of proximal, mid and distal small intestine were measured. Intestinal mucosa was scraped, weighed and homogenized for estimation of protein, DNA and disaccharidases. Na⁺ transport was examined in short-circuited jejunum. Weight gain was similar in controls, sham-treated and TPN animals, but was significantly reduced in IG animals. TPN induced precocious development of sucrase and maltase activity and glucose-stimulated Na⁺ transport, despite causing a significant decrease in mucosal weight and DNA and pancreatic amylase. IG alimentation also induced precocious development of sucrase, maltase and glucose-stimulated Na⁺ transport. Thus TPN, despite producing mucosal atrophy and decreased pancreatic exocrine development, stimulates accelerated postnatal maturation of the small intestine.

Effects of Suckling and the Postsuckling Fast on Weights of the Body and Internal Organs of Harp and Hooded Seal Pups

“…The in gestion of milk results in rapid growth of the intestines in the first 1-3 days after birth in pigs, rabbits, rats and dogs [1][2][3][4], It appears that the amount and composition of milk or formula and the frequency of intake may have effects on growth of the intestines and other organs in the young of these species [3][4][5][6][7], As mammals exhibit widely different lactation patterns, including differences in milk composition, milk yield and suckling frequency [8,9], we expected that there might be substantial differences among spe cies, not only in growth rate of the body as a whole, but also in the relative growth pat terns of individual organs during the suck ling period. This paper describes a compari son of the patterns of weight change of the body and internal organs of the young of two marine mammals, the harp seal (Phoca groenlandica) and the hooded seal (Cyslophora cristata).…”

Glucagon-Like Peptide 2 Enhances Maltase-Glucoamylase and Sucrase-Isomaltase Gene Expression and Activity in Parenterally Fed Premature Neonatal Piglets

“…TPN provides systemic energy and nutrients but has been associated with intestinal atrophy, abnormal BB hydrolase activities, and reduced circulating GLP-2 concentrations (1)(2)(3)(4)(5). GLP-2 is a 33-amino acid peptide released from the specific post-translational cleaving of the proglucagon gene in the enteroendocrine L cells of the small intestine.…”

“…Some investigators (2,12,13) report significant decreases in major enzyme activities (lactase, maltase, sucrase, aminopeptidase, and dipeptidyl peptidase), whereas others report marked increases (3,4) during TPN. Regardless of the differences in these results, it is well recognized that the activity of BB hydrolases cannot be sustained at normal levels by parenteral nutrition alone.…”

Short Bowel Syndrome

“…In growing or neonatal animals, TPN and bowel rest will maintain normal body growth but will result in reduced bowel length, gastric and pancreatic hypoplasia [33][34][35][36]. Despite the occurrence of mucosal hypoplasia, the development of disaccharidase enzymes and glucose transport is accelerated and mucosal levels of these enzymes increased in neonatal animals receiving TPN [34,36].…”

“…Despite the occurrence of mucosal hypoplasia, the development of disaccharidase enzymes and glucose transport is accelerated and mucosal levels of these enzymes increased in neonatal animals receiving TPN [34,36]. Hypoplasia occurred mainly in the proximal small bowel and is less evident distally [35].…”