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Background Since short bowel syndrome (SBS) patients face life-threatening conditions, the development of therapeutic strategies to induce intestinal adaptation has been investigated. Ghrelin, a ligand of growth hormone (GH) secretagogue-receptor that stimulates the release of GH and insulin like growth factor-1 (IGF-1), has several pleiotropic effects. We investigated whether ghrelin induces intestinal adaptation in parenterally fed rats with SBS. Methods Sprague-Dawley rats underwent venous catheterization and were divided into 3 groups: those receiving 90% small bowel resection while leaving the proximal jejunum and distal ileum (90% SBR) with TPN (SBS/TPN group), those receiving 90% SBR with TPN + ghrelin (SBS/TPN/ghrelin group), and those receiving sham operation and fed chow (sham group). Ghrelin was administered intravenously at 10 μg/kg/day. On Day 13, the rats were euthanized and the small intestine harvested, and the histology and crypt cell proliferation rates (CCPR), apoptosis, and nutrient transporter protein levels were analyzed and the plasma hormones were measured. Results The villus height and crypt depth of the ileum in the SBS/TPN/ghrelin group were significantly higher than in the SBS/TPN group. The CCPR of the jejunum and the ileum significantly increased by the administration of ghrelin; however, the apoptosis rates did not significantly differ between the SBS/TPN and SBS/TPN/ghrelin groups. Significant differences did not exist in the plasma IGF-1 and nutrient transporter protein levels among three groups. Conclusions The intravenous administration of ghrelin stimulated the morphological intestinal adaptation of the ileum to a greater degree than the jejunum due to the direct effect of ghrelin.

Extensive literature is available about the intrinsic denervation of segments of the digestive tube through the application of CB in the serosa of the viscera. However, this technique has some disadvantages like causing peritonitis, flanges and high mortality, limiting its use in humans. The aim of the present study was to evaluate the feasibility of benzalkonium chloride (CB) to induce intrinsic chemical denervation, through applications of CB in the intramural ileum of wistar rats, as well as deepen the knowledge about the evolution of neuronal injury caused in the process. We used 40 rats, divided into two groups (control-GC and benzalkonium-GB) of 20 animals each, divided into four sub-groups according to the time of postoperative assessment of 24, 48 hours, 30 and 90 days. The animals were submitted to intramural microinjections of sterile saline solution 0.9% (GC) or benzalkonium chloride (GB) in ileal portion, and subsequent histopathological analysis and immunohistochemistry for evaluation of neuronal injury. A significant decrease (p

Extensive literature is available about the intrinsic denervation of segments of the digestive tube through the application of CB in the serosa of the viscera. However, this technique has some disadvantages like causing peritonitis, flanges and high mortality, limiting its use in humans. The aim of the present study was to evaluate the feasibility of benzalkonium chloride (CB) to induce intrinsic chemical denervation, through applications of CB in the intramural ileum of wistar rats, as well as deepen the knowledge about the evolution of neuronal injury caused in the process. We used 40 rats, divided into two groups (control-GC and benzalkonium-GB) of 20 animals each, divided into four sub-groups according to the time of postoperative assessment of 24, 48 hours, 30 and 90 days. The animals were submitted to intramural microinjections of sterile saline solution 0.9% (GC) or benzalkonium chloride (GB) in ileal portion, and subsequent histopathological analysis and immunohistochemistry for evaluation of neuronal injury. A significant decrease (p

Submitted by Juliana de Oliveira Ribeiro null (juliana.oribeiro@yahoo.com.br) on 2017-09-14T18:57:17Z No. of bitstreams: 1 DISSERTAÇÃO MESTRADO_ JULIANA_DEFESA_FINAL_TUDO.pdf: 1185953 bytes, checksum: 43de0b8a3f6d86f80ccdac01811a5b23 (MD5) Rejected by Luiz Galeffi (luizgaleffi@gmail.com), reason: Solicitamos que realize uma nova submissão seguindo as orientações abaixo: No campo “Versão a ser disponibilizada online imediatamente” foi informado que seria disponibilizado o texto completo porém no campo “Data para a disponibilização do texto completo” foi informado que o texto completo deverá ser disponibilizado apenas 6 meses após a defesa. Caso opte pela disponibilização do texto completo apenas 6 meses após a defesa selecione no campo “Versão a ser disponibilizada online imediatamente” a opção “Texto parcial”. Esta opção é utilizada caso você tenha planos de publicar seu trabalho em periódicos científicos ou em formato de livro, por exemplo e fará com que apenas as páginas pré-textuais, introdução, considerações e referências sejam disponibilizadas. Se optar por disponibilizar o texto completo de seu trabalho imediatamente selecione no campo “Data para a disponibilização do texto completo” a opção “Não se aplica (texto completo)”. Isso fará com que seu trabalho seja disponibilizado na íntegra no Repositório Institucional UNESP. Por favor, corrija esta informação realizando uma nova submissão. Agradecemos a compreensão. on 2017-09-15T14:06:47Z (GMT) Submitted by Juliana de Oliveira Ribeiro null (juliana.oribeiro@yahoo.com.br) on 2017-09-16T01:19:58Z No. of bitstreams: 1 DISSERTAÇÃO MESTRADO_ JULIANA_DEFESA_FINAL_TUDO.pdf: 1185953 bytes, checksum: 43de0b8a3f6d86f80ccdac01811a5b23 (MD5) Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-09-26T12:36:45Z (GMT) No. of bitstreams: 1 ribeiro_jo_me_jabo_parc.pdf: 709630 bytes, checksum: 3c5ed2da5fe9595a6ff29a81ae11460d (MD5) Made available in DSpace on 2017-09-26T12:36:45Z (GMT). No. of bitstreams: 1 ribeiro_jo_me_jabo_parc.pdf: 709630 bytes, checksum: 3c5ed2da5fe9595a6ff29a81ae11460d (MD5) Previous issue date: 2017-07-28 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) A síndrome do intestino curto (SIC) representa condição clínica grave na medicina, caracterizada pela deficiente absorção intestinal de nutrientes, causada pela perda extensa do intestino delgado, culminando em altas taxas de mortalidade tanto em pacientes humanos quanto veterinários. Os tratamentos disponíveis não possuem, até então, resultados satisfatórios para resolução desta importante afecção e consistem em terapias paliativas. Diversos estudos demostraram que o método de desnervação intestinal intrínseca, com utilização do Cloreto de Benzalcônio (CB), consiste em promissora esperança na busca de terapias menos invasivas e eficazes no tratamento da SIC, permitindo melhora nas condições pós-cirúrgicas e prognóstico dos pacientes, por aumentar a área absortiva do intestino. Objetivou-se, com esse trabalho, avaliar a capacidade do CB induzir desnervação química intrínseca, por meio de aplicações intramurais em íleo de ratos Wistar e aprofundar o conhecimento sobre a evolução da lesão neuronal causada neste processo. Foram utilizados 40 ratos, distribuídos em dois grupos (controle- GC e benzalcônio- GB) de 20 animais cada, subdivididos em quatro subgrupos de acordo com o tempo de avaliação pós-operatória de 24, 48 horas, 30 e 90 dias. Os animais foram submetidos à microinjeções intramurais de solução salina estéril 0,9% (GC) ou de cloreto de benzalcônio (GB) em porção ileal, e posterior análise histopatológica e imuno-histoquímica, para avaliação da lesão neuronal. Houve diminuição significativa (p

Numerous cytokines have been shown to affect epithelial cell differentiation and proliferation through epithelial-mesenchymal interaction. Growing evidence suggests that platelet-derived growth factor (PDGF) signaling is an important mediator of these interactions. The purpose of this study was to evaluate the effect of PDGF-α on enterocyte turnover in a rat model of short bowel syndrome (SBS). Male rats were divided into four groups: Sham rats underwent bowel transection, Sham-PDGF-α rats underwent bowel transection and were treated with PDGF-α, SBS rats underwent a 75% bowel resection, and SBS-PDGF-α rats underwent bowel resection and were treated with PDGF-α. Parameters of intestinal adaptation, enterocyte proliferation and apoptosis were determined at euthanasia. Illumina's Digital Gene Expression analysis was used to determine PDGF-related gene expression profiling. PDGF-α and PDGF-α receptor (PDGFR-α) expression was determined by real-time PCR. Western blotting was used to determine p-ERK, Akt1/2/3, bax, and bcl-2 protein levels. SBS rats demonstrated a significant increase in PDGF-α and PDGFR-α expression in jejunum and ileum compared with sham animals. SBS-PDGF-α rats demonstrated a significant increase in bowel and mucosal weight, villus height, and crypt depth in jejunum and ileum compared with SBS animals. PDGF-α receptor expression in crypts increased in SBS rats (vs. sham) and was accompanied by an increased cell proliferation following PDGF-α administration. A significant decrease in cell apoptosis in this group was correlated with lower bax protein levels. In conclusion, in a rat model of SBS, PDGF-α stimulates enterocyte turnover, which is correlated with upregulated PDGF-α receptor expression in the remaining small intestine.

Background Glucagon-like peptide-2 induces small intestine mucosal epithelial cell proliferation and may have benefit for patients who suffer from short bowel syndrome. However, glucagon-like peptide-2 is inactivated rapidly in vivo by dipeptidyl peptidase IV. Therefore, we hypothesized that selectively inhibiting dipeptidyl peptidase IV would prolong the circulating life of glucagon-like peptide-2and lead to increased intestinal adaptation after development of short bowel syndrome. Methods Eight-week old C57BL/6J mice underwent a 50% proximal small bowel resection and were treated with either sitagliptin, a dipeptidyl peptidase IV-inhibitor, starting 1 day before surgery versus placebo. The efficacy of dipeptidyl peptidase IV-inhibitor was assessed 3 days after resection, including intestinal morphology, epithelial cell apoptosis, and epithelial cell proliferation. Adaptive mechanisms were assessed with quantitative real-time polymerase chain reaction, and plasma bioactive glucagon-like peptide-2 was measured by radioimmunoassay. Results Body weight loss and peripheral blood glucose levels did not change compared with short bowel syndrome controls. Dipeptidyl peptidase IV-inhibitor treatment led to significant increases in villus height and crypt depth. Dipeptidyl peptidase IV-inhibitor treatment did not change EC apoptosis rates significantly, but it did increase crypt epithelial cell proliferation significantly versus placebo-short bowel syndrome controls. Dipeptidyl peptidase IV-inhibitor treatment markedly increased messenger RNA expression of β-catenin and c-myc in ileal mucosa. Plasma glucagon-like peptide-2 levels increased significantly (∼40.9%) in dipeptidyl peptidase IV-inhibitor short bowel syndrome mice. Conclusion Dipeptidyl peptidase IV-inhibitor treatment increased short bowel syndrome adaptation and might potentially be useful for short bowel syndrome patients.

The purpose of the present study was to evaluate the effects of ω-3 fatty acids (Omegaven) on early intestinal adaptation in rats with short bowel syndrome (SBS).Male Sprague-Dawley rats were randomly assigned to 1 of 4 groups: sham rats underwent bowel transection; SBS rats underwent 75% bowel resection; SBS-O ω-3 rats underwent bowel resection and were treated with oral Omegaven given by gavage; and SBS-I ω-3 rats underwent bowel resection and were treated with Omegaven given intraperitoneally. Rats were killed on day 14. Parameters of intestinal adaptation (bowel and mucosal weight, mucosal DNA and protein, villus height and crypt depths, cell proliferation and apoptosis) were determined at time of death. Real-time polymerase chain reaction was used to determine the level of Bax and Bcl-2 messenger RNA (mRNA). Statistical analysis was performed using Kruskal-Wallis test followed by post hoc test, with P.05 considered statistically significant.Oral ω-3 supplementation did not significantly change intestinal regrowth. In contrast, parenteral ω-3 in rats that underwent resection resulted in higher bowel and mucosal weights, mucosal DNA and protein in ileum, villus height in ileum, crypt depth in jejunum and ileum, and greater rates of cell proliferation in jejunum and ileum compared with SBS animals. The initial decreased levels of apoptosis corresponded with the early decrease in Bax and increase in Bcl-2 mRNA levels.Parenteral but not enteral Omegaven augments and accelerates structural bowel adaptation in a rat model of SBS. Increased cell proliferation and decreased apoptosis reflect increased cell turnover in Omegaven-treated animals.

Objectives: The purpose of the present study was to evaluate the effects of exogenous bilirubin on structural intestinal adaptation, cell proliferation, and apoptosis in a rat model of short bowel syndrome (SBS). Materials and Methods: Male Sprague-Dawley rats were divided into 5 experimental groups: Sham rats underwent bowel transection and reanastomosis, sham multiple doses of bilirubin (MDB) rats underwent bowel transection and were treated with bilirubin, SBS rats underwent a 75% small bowel resection, SBS-SDB (single dose bilirubin) rats underwent a bowel resection and were treated with a single dose of bilirubin, and SBS-MDB underwent a bowel resection and were treated with 3 doses of bilirubin. Bilirubin was administered intraperitoneally from the 7th day through the 14th day postoperatively. Serum total bilirubin concentration over time was evaluated in 5 SBS-SDB rats following a single intraperitoneal dose. Total bilirubin, alanine aminotransferase, and aspartate aminotransferase in serum and parameters of intestinal adaptation, enterocyte proliferation, and enterocyte apoptosis were determined on day 15. Results: SBS-SDB and SBS-MDB animals demonstrated lower ileal bowel and mucosal weights, jejunal mucosal DNA and ileal mucosal protein, and jejunal and ileal villus height and crypt depth (vs SBS animals). Bilirubin-treated rats showed a lower apoptotic index in jejunum and ileum and a trend toward an increase in cell proliferation in jejunum and ileum (vs SBS group). Conclusions: In a rat model of SBS, exogenous bilirubin inhibits structural intestinal adaptation. Increased cell proliferation and decreased apoptosis may be considered adaptive mechanisms that maintain cell mass.

Glutathione (GSH) concentration affects cell proliferation and apoptosis in intestinal and other cell lines in vitro. However, in vivo data on gut mucosal GSH redox status and cell turnover are limited. We investigated the effect of altered GSH redox status on the ileal mucosa in a rat model of short bowel syndrome following massive small bowel resection (SBR). Rats underwent 80% mid-jejunoileal resection (RX) or small bowel transection (TX; as operative controls), with administration of either saline or o, L-buthionine-sulfoximine (BSO), a specific inhibitor of cellular GSH synthesis. Ileal mucosal redox, morphology, and indices of cell proliferation and apoptosis were determined at different days after surgery. Ileal GSH redox status was assessed by GSH and GSH disulfide (GSSG) concentrations and the redox potential of GSH/GSSG (E h ). Ileal lipid peroxidation [free malondialdehyde (MDA)] was measured as an index of lipid peroxidation. BSO markedly decreased ileal mucosal GSH, oxidized GSH/GSSG E h , and increased MDA content without inducing morphological damage as assessed by light or electron microscopy. As expected, SBR stimulated adaptive growth of ileal villus height and total mucosal height at 7 d after surgery, but this response was unaffected by BSO treatment despite a modest increase in crypt cell apoptosis. Ileal cell proliferation (crypt cell bromodeoxyuridine incorporation) increased at 2 d after SBR but was unaffected by BSO. Collectively, our in vivo data show that marked depletion of ileal GSH and oxidation of the GSH redox pool does not alter indices of ileal epithelial proliferation or SBR-induced ileal mucosal adaptive growth.

Recent evidence suggests that the adipose tissue-derived cytokine leptin (LEP) is involved in modulation of growth and differentiation of normal small intestine. The purpose of the present study was to evaluate the effects of parenteral LEP on structural intestinal adaptation, cell proliferation and apoptosis in a rat model of short bowel syndrome (SBS). Male Sprague-Dawley rats were divided into three experimental groups: Sham rats underwent bowel transection and re-anastomosis, SBS-rats underwent a 75% small bowel resection, and SBS-LEP-rats underwent bowel resection and were treated with LEP given subcutaneously at a dose of 20 mug/kg, once daily, from day 3 through 14. Parameters of intestinal adaptation (bowel and mucosal weights, mucosal DNA and protein, villus height and crypt depth in jejunum and ileum), enterocyte proliferation and enterocyte apoptosis were determined on day 15 following operation. Ileal tissue samples were taken for detection of bax and bcl-2 gene expression using RT-PCR technique. Statistical analysis was performed using the non-parametric Kruskal-Wallis ANOVA test, with P

OBJECTIVE: To study the effects and the underlying mechanism of recombinant human growth hormone (rhGH) and glutamine (Gln) on the adaptation of the remnant small intestine in parenterally nourished, short bowel syndrome (SBS) rats. METHOD: Four parenteral nutrition (PN) treatment groups of SBS rats were randomly arranged in a 2 × 2 factorial design as follows: (i) STD (standard PN) group (–rhGH, –Gln); (ii) Gln group (–rhGH, +Gln); (iii) rhGH group (+rhGH, –Gln); and (iv) rhGH + Gln group (+rhGH, +Gln). Morphological changes of the intestinal mucosa were investigated and the expression of proliferating cell nuclear antigen (PCNA) and the occurrence of apoptosis were observed by immunohistochemical staining and terminal deoxynucleotidyl transfer-mediated dUTP-biotin nick end-labeling (TUNEL) methods. The level of intestinal insulin-like growth factor-1 (IGF-1) mRNA was determined by northern blotting. RESULTS: The mucosal thickness, villous height, crypt depth and villous surface area of the remnant small intestine in the rhGH + Gln group were increased significantly as compared with the other three experimental groups, and there were synergistic effects between rhGH and Gln (P < 0.01). The expression of PCNA was higher in the rhGH + Gln group than in the rhGH, Gln and STD groups (24.95 ± 3.93 vs 19.28 ± 3.25, 17.27 ± 3.38, and 8.37 ± 2.23 positive cells per crypt of Lieberkuhn, respectively; P < 0.01) but the rate of apoptosis was lower in the rhGH + Gln group than in the rhGH, Gln and STD groups (5.68 ± 2.07 vs 8.06 ± 2.33, 10.00 ± 2.24 and 22.32 ± 3.84 positive cells per 100 cells, respectively; P < 0.01). The intestinal IGF-1 mRNA was also expressed at a higher level in the rhGH + Gln group than in the rhGH, Gln and STD groups (0.73 ± 0.05 vs 0.62 ± 0.04 vs 0.51 ± 0.04 and 0.41 ± 0.22, respectively; P < 0.05). CONCLUSION: The synergistic combination of rhGH and Gln can significantly improve the adaptation of the remnant small intestine in parenterally fed SBS rats. An increase in cell proliferation and a decrease in cell apoptosis are both responsible for the intestinal adaptation. An increase in local IGF-1 plays an important role in this process.

This study was performed to compare the effects of recombinant human growth hormone (rhGH), glutamine (Gln) and simultaneous treatment with rhGH and Gln in rats subjected to 75% intestinal resection and maintained with parenteral nutrition (PN) for 6 days. Morphological changes including mucosal thickness, villus height, crypt depths and villus surface area of the residue jejunum were measured under a light microscope; expression of PCNA as an index of cell proliferation and apoptotic cells were observed using immunohistochemical staining; Ileal IGF-1 mRNA was determined by Northern blot analysis. The morphological parameters of the jejunal mucosa in rats treated with PN alone were only about 52-62% of those in reference group (P

Intestinal adaptation after loss of functional small bowel surface area is characterized by cellular hyperplasia and increased absorptive function. Interventions to enhance the adaptive response are needed to decrease the morbidity and mortality associated with short bowel syndrome. Retinoic acid was shown to stimulate crypt cell proliferation in the adapting remnant rat ileum by 6 hours after resection. Thus, vitamin A, which is required for normal epithelial cell proliferation and differentiation and which can modulate programmed cell death, may play an important role in the adapting intestine. On the basis of these observations, the effects of vitamin A deficiency on intestinal morphology, epithelial cell proliferation, and apoptosis in the adapting intestine after resection were investigated.Weanling male Sprague-Dawley rats fed either a vitamin A-deficient or -sufficient diet for 58 days underwent 70% proximal small bowel resection. The deficient rats were divided into cohorts that were either maintained on the experimental diet after surgery or replenished with vitamin A 20 hours before surgery and switched to the control diet after surgery.Ten days after resection, vitamin A-deficient rats exhibited a markedly blunted adaptive response. The adaptive increase in villus height and crypt depth was absent in the deficient rats. However, adaptive increases in crypt cell proliferation were not attenuated by vitamin A deficiency, and there were no differences in apoptotic indices.Vitamin A deficiency inhibits the adaptive response to partial small bowel resection, supporting a role for vitamin A in the adaptive process. Changes in cellular proliferation or programmed cell death are not sufficient to account for this inhibition. This model system will be useful for examining the role of other mechanisms, such as changes in cell-cell and cell-extracellular matrix interactions, and rates of epithelial cell migration and cell extrusion.

Background Interposition of a reversed intestinal segment as a factor facilitating intestinal adaptation has been experimentally investigated. Controversy exists about its efficacy in terms of body weight improvement, direction of luminal changes, and underlying mechanisms. This study aims to provide a comprehensive approach. Methods The pigs were randomly allocated to two groups: (1) short bowel (SB) group ( n = 8) and (2) short bowel reverse jejunal segment (SB-RS) group ( n = 8). On postoperative d 3, 30, and 60, intestinal transit time was measured; body weight and serum albumin were measured on baseline, as well as on postoperative d 30 and 60. After sacrifice, histopathologic and immunohistochemical (PCNA, activated caspase-3) evaluation followed. Results Transit time was numerically longer in SB-RS group at all time points; the difference reached statistical significance on d 60. No statistically significant differences were observed concerning body weight or serum albumin. In the SB-RS group, a statistically significant increase in muscle thickness, crypt depth, villus height, and PCNA immunostaining, and a decrease in caspase-3 positive (+) cell count were documented both at the jejunal and ileal level. Conclusions The reversed jejunal segment seemed able to enhance intestinal adaptation at a histopathologic level, as well as to favorably modify transit time. These putatively beneficial actions were not reflected upon body weight. The decrease in apoptosis was caspase-3-dependent.

In this study, we examine the responsiveness of intestinal epithelial cell turnover to leptin (LEP) in correlation with leptin receptor (LEPr) expression along the villus-crypt axis in a rat with short bowel syndrome (SBS). Adult rats underwent either a 75% intestinal resection or a transection. SBS-LEP rats underwent bowel resection and were treated with LEP starting from the fourth postoperative day. Parameters of intestinal adaptation, enterocyte proliferation, and enterocyte apoptosis were determined at sacrifice. RT-PCR technique was used to determine Bax and Bcl-2 gene expression in ileal mucosa. Villus tips, lateral villi, and crypts were separated using laser capture microdissection. LEPr expression for each compartment was assessed by quantitative real-time PCR (Taqman). Treatment with LEP significantly stimulated all parameters of adaptation. LEPr expression in crypts significantly increased in SBS rats (vs Sham rats) and was accompanied by a significant increase in enterocyte proliferation and decreased apoptosis after LEP administration. A significant increase in LEPr expression at the tip of the villus in SBS rats was accompanied by decreased cell apoptosis. In conclusion LEP accelerated enterocyte turnover and stimulated intestinal adaptation. The effect of LEP on enterocyte proliferation and enterocyte apoptosis correlated with receptor expression along the villus-crypt axis.

Background Thyroid hormone acts on structural and functional maturation of the mammalian small intestine, mitochondrial pathways, and several protein–gene interactions. Therefore, it is one of the most important regulators of intestinal epithelial differentiation. The aim of the study was to evaluate the effects of thyroid hormone on the adaptation in an experimental model of short bowel syndrome. Methods Rats were divided into three groups: sham (bowel transection and anastomosis), short bowel syndrome-saline (75% bowel resection and anastomosis), and short bowel syndrome-thyroid hormone (75% bowel resection and anastomosis, and was administered triiodothyronine). The evaluation of adaptation parameters, histopathological and biochemical analysis were performed in all groups. Results Triiodothyronine treatment resulted in a significant increase in adaptation parameters, villus height-crypt depth, and enterocyte proliferation, whereas significant decrease was seen in apoptotic index in jejunum. Enterocyte proliferation and most of the adaptation parameters changed significantly in ileum following the treatment with triiodothyronine as in jejunum. The changes in ileal villus height-crypt depth and apoptotic index were not statistically significant. Serum levels of free triiodothyronine were lower in the short bowel syndrome-saline group. Conclusions Our results suggest that thyroid hormone treatment in the hypothyroid phase of SBS enhances intestinal adaptive response.

The objective of the present study was to examine the effect of glucagon-like peptide-2 (GLP-2) administration in a piglet, juvenile model of short bowel syndrome.Four-week-old piglets underwent either a sham operation or 75% small bowel resection. Postoperatively, piglets received either polymeric infant formula diet or the diet and subcutaneous human recombinant GLP-2 (1600 microg/day for 7 days, 800 microg/day thereafter). Food intake was monitored throughout the experiment, and stool and serum samples obtained fortnightly. After the piglets were killed, tissues were obtained from the duodenum, jejunum, ileum, and terminal ileum, and used for morphological and functional analysis.Treatment with GLP-2 resulted in significantly increased numbers of proliferating and apoptotic cells in the ileum of sham and small bowel resection piglets (P0.05). GLP-2 administration resulted in decreased weight gain, serum albumin, and disaccharidases in both sham and small bowel resection piglets (P0.001 compared with polymeric infant formula diet alone).This is the first study to our knowledge to examine the effect of GLP-2 administration in a juvenile short bowel syndrome model. Contrary to adult rodent studies, administration of GLP-2 resulted in adverse outcomes including reduced ability to gain weight; decreased serum albumin, tissue maltase, and sucrase; and villous atrophy. We anticipate this information will have important implications for future paediatric clinical trials.

Recent evidence suggests that bombesin (BBS) is involved in modulation of growth and differentiation of normal small intestine. The purpose of the present study was to evaluate the effects of BBS on enterocyte turnover after massive small bowel resection in a rat. Male Sprague-Dawley rats were divided into three experimental groups: Sham rats underwent bowel transection and re-anastomosis, short bowel syndrome (SBS) rats underwent a 75% small bowel resection, and SBS-BBS rats underwent bowel resection and were treated with BBS given subcutaneously at a dose of 20 mug/kg, once daily, from postoperative day 3 through 14. Parameters of intestinal adaptation (bowel and mucosal weights, mucosal DNA and protein, villus height and crypt depth), enterocyte proliferation and enterocyte apoptosis were determined in jejunum and ileum on day 15 following operation. RT-PCR technique was used to determine Bax and Bcl-2 gene expression in ileal mucosa. Statistical analysis was performed using the non-parametric Kruskal-Wallis ANOVA test, with P less than 0.05 considered statistically significant. Treatment with BBS resulted in a significant increase in ileal bowel and mucosal weight, ileal mucosal DNA and protein, jejunal and ileal villus height, jejunal crypt depth, and jejunal and ileal proliferation index compared to SBS-animals. SBS rats showed a significant increase in Bax and Bcl-2 expression in ileum that was accompanied by a significant increase in cell apoptosis compared to sham animals. SBS-BBS rats demonstrated a significant decrease in Bax and Bcl-2 expression in ileum and a decrease in apoptotic index compared to SBS-animals. In conclusion, in a rat model of SBS, BBS enhances enterocyte turnover and stimulates structural intestinal adaptation. Decreased Bax expression may be responsible for the inhibitory effect of BBS on enterocyte apoptosis.

Following the loss of functional small bowel surface area, the intestine undergoes a compensatory adaptive response. The observation that adaptation is inhibited in vitamin A-deficient rats following submassive intestinal resection suggested that vitamin A is required for this response and raised the possibility that exogenous vitamin A could augment adaptation. Therefore, to directly assess whether chronically administered retinoic acid could stimulate gut adaptation in a model of short bowel syndrome and to address the mechanisms of any such effects, Sprague-Dawley rats were implanted with controlled release retinoic acid or control pellets and then subjected to mid-small bowel or sham resections. At 2 wk postoperation, changes in gut morphology, crypt cell proliferation and apoptosis, enterocyte migration, the extracellular matrix, and gene expression were assessed. Retinoic acid had significant trophic effects in resected and sham-resected rats. Retinoic acid markedly inhibited apoptosis and stimulated crypt cell proliferation and enterocyte migration postresection. Data presented indicate that these proadaptive effects of retinoic acid may be mediated via changes in the extracellular matrix (e.g., by increasing collagen IV synthesis, decreasing E-cadherin expression, and reducing integrin β3levels), via affects on Hedgehog signaling (e.g., by reducing expression of the Hedgehog receptors Ptch and Ptch2 and the Gli1 transcription factor), by increasing expression of Reg1 and Pap1, and by modulation of retinoid and peroxisome proliferator-activated receptor signaling pathways. These studies are the first to demonstrate that retinoic acid can significantly enhance intestinal adaptation and suggest it may be beneficial in patients with short bowel syndrome.

Background. Following massive small bowel resection (SBR), the expression of bax and bcl-w is associated with increased enterocyte apoptosis. Epidermal growth factor (EGF) has been shown to enhance enterocyte proliferation and retard apoptosis in the adapting bowel. This study examined the effect of EGF on the expression of these bcl-2 family members during adaptation. Materials and methods. Mice (C57Bl/6; n = 38) underwent a 50% SBR or sham operation and then were randomized to receive twice-daily orogastric saline or EGF (50 μg/kg/day). After 3 days, the remnant ileum was removed, apoptotic index (No. apoptotic bodies/crypt) calculated, and expression of mRNA and protein for bax and bcl-w quantified. Results. EGF prevented the expected increase in the apoptotic index after SBR and altered the ratio of bax to bcl-w in favor of cell survival. Conclusion. Following massive small bowel resection, EGF retards rates of enterocyte apoptosis and modifies the expression of bcl-2 family members. By decreasing bax and increasing bcl-w expression, the balance between pro- and anti-apoptotic genes is shifted in favor of cell survival. Alteration of bcl-2 family member expression may be an important mechanism by which EGF reduces the increased enterocyte apoptosis that occurs after massive small bowel resection.