Crypt fission contributes to postnatal epithelial growth of the small intestine in pigs

Studies on growth of the small intestine have mostly concentrated on crypt hyperplasia rather than crypt fission (CF). The process of crypt bifurcation has been identified in rodents and humans but not in swine. The main aims of this study were: 1) to investigate quantitatively crypt fission in the small intestine mucosa of pigs of different age-groups and 2) to assess the effect of colostrum and milk on small intestine growth via CF. Five groups of piglets were studied: non-suckling piglets, euthanized just after delivery (C0) suckling piglets, euthanized 24 h after delivery (C1) and then piglets that were euthanized at 7.28 and 180 days of life (C7, C28, C180 respectively). Samples of duodenum, jejunum (proximal, middle and distal) and ileum were taken for the evaluation of the percentage of bifid crypts. Our results show that the 24 h suckling period has no effect on the percentage of bifid crypts compared to the non-suckling, newborn piglets (C0). Moreover, we observed that the rate of bifid crypts depends predominantly on the age of the piglets and the part of intestine examined and less on the feed components. The highest CF is observed during the first 28 days of life and then declines significantly at day 180. In duodenum and proximal jejunum there were no significant changes between groups of piglets in age till 28 days of life whereas in further parts we observed a decrease of bifid crypts comparing C0 and C1 with C7. In conclusion, our data shows that CF contributes to epithelial growth of the small intestine in piglets. The peak of bifid crypts was observed during suckling, thus CF can be described as a marker for intestinal growth during the early postnatal period. (C) 2010 Elsevier B.V. All rights reserved

Enteral leptin administration affects intestinal autophagy in suckling piglets

Leptin has been shown to play an integral role in the endocrine regulation of metabolism. Moreover, a substantial amount of this peptide has been found in colostrum and milk. The aim of the study was to investigate the effects of exogenous leptin, administered intragastrically, on the process of autophagy and the changes in cell hyperplasia and hypertrophy in the small intestine mucosa. Three groups (n = 6) of neonatal piglets were used in the study. The pigs were fed either by their sows (sow-reared piglets) or with only milk formula, or with milk formula together with leptin administered via a stomach tube (10 mu g/kg BW) every 8 h for 6 d. We have shown that pure milk formula feeding significantly elevates (P < 0.05) autophagy compared with that observed in sow-reared piglets. Compared with the control group, feeding milk formula supplemented with leptin resulted in a significant decrease (P < 0.05) in immunodetection of microtubule-associated protein 1 light chain 3, as well as significantly accelerated epithelial cell renewal (P < 0.05). We demonstrated that autophagy is involved in the remodeling of the small intestine mucosa and that leptin, when administered enterally, may be an important factor for its regulation. (C) 2014 Elsevier Inc. All rights reserved

Age-dependent effect of obestatin on intestinal contractility in Wistar rats

Obestatin is a 23-amino acid peptide encoded by the ghrelin gene. We have investigated the effect of obestatin on intestinal contractility in rats ranging from the suckling period till adolescence. Duodenal and middle jejunum whole-thickness preparations from neonatal and adult rats were studied in an organ bath, for isometric recording under treatment with obestatin (1 mu mol L-1) in the presence of acetylocholine (ACh), atropine and tetradotoxin (TTX). Both the EFS and ACh-stimulated contractile response, as well as spontaneous contractile activity is age-dependent and specific for the segment of jejunum. Except for the middle jejunum of 7 day old rats, treatment with obestatin caused a significant TTX-sensitive increase in the amplitude of EFS-stimulated off-contraction of both intestinal segments studied. Following injection of obestatin, the amplitude of spontaneous contraction in the duodenum increased in 7 day old rats. In the middle jejunum, treatment with obestatin significantly increased both the amplitude and frequency of spontaneous contraction in rats till the 28th day of life, whereas in adult rats the observed effect of obestatin was the opposite (P < 0.001 and P < 0.0001, respectively). The effects of treatment with obestatin on stimulation with increasing doses of ACh were only observed in the preparations from suckling rats. ACh-stimulated contractility in the duodenum was decreased while in the middle jejunum the observed effect was opposite. These results indicate the importance of peripheral obestatin in the cholinergic control of intestinal contractility in both neonatal and adult rats. (C) 2014 Elsevier Inc. All rights reserved

Stimulating effect of pancreatic-like enzymes on the development of the gastrointestinal tract in piglets

Use of nutritional components from the milk and eventually from the solid feed relates to the growth and development of gastrointestinal tract (GIT). We studied the effect of pancreatic-like enzymes [porcine pancreatic enzymes (Creon) or microbial-derived amylase, protease, and lipase] on GIT morphology and lipid absorption in suckling piglets. Both enzyme preparations, in low or high dose, were fed via a stomach tube twice a day for 7 d starting at 8 d of age and controls received vehicle, n = 6. The day after treatments ended, lipid absorption was tested after which pigs were euthanized and GIT was examined. Enzyme cocktails, irrespective of their origin, increased (P < 0.001) triglyceride level in blood. Enzyme preparation affected (P < 0.001) small intestinal mucosal thickness, villi length, and crypt depth and (P < 0.01) mitotic division of enterocytes. In addition, the external administration of pancreatic enzymes stimulated pancreatic growth as observed by increased (P < 0.05) mitotic division of pancreatic cells. The study revealed that pancreatic or pancreatic-like enzymes of microbial origin administrated in the early postperinatal period enhance GIT development and may be used to better prepare the GIT of piglets for milk use and weaning

Effect of feeding colostrum versus exogenous immunoglobulin G on gastrointestinal structure and enteric nervous system in newborn pigs

Colostrum is an indispensable source of antibodies (IgG) protecting the newborn pig against infection. We studied the effect of feeding colostrum and purified IgG on early structure and development of the gastrointestinal tract (GIT). Newborn littermate pigs were fed either colostrum, an elemental diet (ED), or an ED supplemented with purified serum IgG (ED + IgG) for 24 h or then only ED up to 72 h. Afterwards, pigs were slaughtered. Colostrum-fed pigs or ED supplemented with IgG (ED + IgG) increased thickness (P < 0.001) of stomach mucosa and muscularis (P < 0.05) compared to the ED group not receiving IgG. Feeding an ED supplemented with IgG improved morphology of the GIT towards that of colostrum-fed piglets and indicates a beneficial effect of IgG on GIT development in neonatal pigs. Immunohistochemical studies indicate that ED feeding may influence the expression of nitric oxide synthase in jejunal myenteric (but not submucous) neurons of newborn pigs