DigitalUM :: Browsing by Subject "Gut"

Browsing by Subject "Gut"

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Biological significance of dietary polyamines
(Elsevier, 2006-09-22) Larqué, Elvira; Sabater Molina, María; Zamora, Salvador; Ciencias Sociosanitarias
Polyamines are classically known by their names of putrescine, spermine, and spermidine. They are synthesized endogenously from ornithine and are interconvertible. In addition, an exogenous supply of polyamines is provided by dietary intake and by intestinal absorption from the products of bacterial metabolism. Polyamine uptake occurs almost entirely in the gut, and afterward the various forms are metabolized in different tissues under the strict regulation of ornithine decarboxylase, which is the first enzyme involved in their synthesis. Polyamines are eliminated from the organism by means of oxidation reactions, appearing in urine in all their metabolic forms. Polyamines play an important role in regulating cell growth and proliferation, the stabilization of negative charges of DNA, RNA transcription, protein synthesis, apoptosis, and the regulation of the immune response. They are components of breast milk and might be important in neonatal gut maturation, for which reason the possible supplementation of infant formulas with these compounds is under study.
Open Access
Cellular and molecular mechanisms of intestinal elongation in mammals: the long and short of it
(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2013) Cervantes, Sara
The gastrointestinal tract carries out essential functions for the organism, including the digestion and absorption of nutrients. The cells lining the lumen of the gut tube derive from the endoderm, one of the three germ layers formed during gastrulation. The length of the intestinal tract determines its digestive and absorptive capacity, and so the intestine expands several times the length of the whole body to ensure an adequate absorptive area to meet nutritional demands. However, the endoderm starts out as a small sheet of cells spanning less than the whole length of the head-fold embryo. In order to achieve its final shape and size, the cells in the endoderm undergo extensive growth and profound morphogenetic changes, which are governed by embryonic signaling pathways and transcription factors. This review, based on mouse development, summarizes our current knowledge of the cellular and molecular mechanisms underlying the morphogenetic changes that participate in shaping the mature intestinal tract in vertebrates.
Open Access
Cholinergic, nitrergic and peptidergic (Substance P- and CGRP-utilizing) innervation of the horse intestine. A histochemical and immunohistochemical study
(Murcia : F. Hernández, 2004) Domeneghini, C.; Radaelli, G.; Arrighi, S.; Bosi, G.; Dolera, M.
The small and large intestine of adult horses were histochemically and immunohistochemically investigated in order to evidence components of the intramural nervous system. The general structural organization of the intramural nervous system was examined by using Nissl-thionin staining as well as the anti-neurofilament 200 (NF200) immunoreaction, which demonstrated the presence of neurons in the submucous as well as myenteric plexuses. The additional presence of subserosal ganglia was shown in the large intestine. Acetylcholinesterase (AChEase) activity was observed in both the submucous and myenteric plexuses. Localization of acetylcholine-utilizing neurons was also evidenced by immunohistochemical reactions for choline acetyltransferase (ChAT) and vesicular acetylcholine transporter (VAChT). With both histochemistry and immunohistochemistry possible cholinergic nerve fibres were detected in the inner musculature. The two possible cholinergic co-mediators Calcitonin Gene-Related Peptide (CGRP) and Substance P (SP) have been investigated by an immunohistochemical approach. CGRP immunoreactivity was detected in roundish nerve cell bodies as well as in nerve fibres of the submucous plexus, whereas SP immunoreactivity was evidenced in nerve fibres of the tunica mucosa, in nerve cell bodies and fibres of the submucous plexus and in nerve fibres of the myenteric plexus. NADPH-diaphorase reactivity, which is linked to the synthesis and release of nitric oxide, was detected in nerve cell bodies and nerve fibres of both the submucous and myenteric plexuses as well as in a subserosal localization of the large intestine. The nitrergic components were confirmed by the anti-NOS (nitric oxide synthase) immunoreaction. Results are compared with those of other mammals and related to the complex intestinal horse physiology and pathophysiology.
Open Access
Cholinesterases are down-expressed in human colorectal carcinoma
(Springer, 2006-08-11) Montenegro Arce, María Fernanda; Ruiz Espejo, Francisco; Campoy, F. J.; Muñoz Delgado, Encarnación; Páez de la Cadena, M.; Rodríguez-Berrocal, F. J.; Vidal, C. J.; Bioquímica y Biología Molecular A
The aberrations of cholinesterase (ChE) genes and the variation of ChE activity in cancerous tissues prompted us to investigate the expression of ChEs in colorectal carcinoma. The study of 55 paired specimens of healthy (HG) and cancerous gut (CG) showed that acetylcholinesterase (AChE) activity fell by 32% and butyrylcholinesterase (BuChE) activity by 58% in CG. Abundant AChE-H, fewer AChE-T, and even fewer AChE-R and BuChE mRNAs were observed in HG, and their content was greatly diminished in CG. The high level of the AChE-H mRNA explains the abundance of AChE-H subunits in HG, which as glycosylphosphatidylinositol (GPI)-anchored amphiphilic AChE dimers (GA2 ) and monomers (GA1) account for 69% of AChE activity. The identification of AChE-T and BuChE mRNAs justifies the occurrence in gut of A12, GH4 and PRiMA-containing GA4 AChE forms, besides GH4 , GA4 and GH1 BuChE. The down-regulation of ChEs might contribute to gut carcinogenesis by increasing acetylcholine availability and overstimulating muscarinic receptors.
Open Access
Early acquisition of bowel segment-specific Bcl-2 homolog expression profiles during development of the human ileum and colon
(Murcia : F. Hernández, 2001) Vachon, P.H.; Cardin, E.; Harnois, C.; Reed, J.C.; Plourde, A.; Vézina, A.
The adult small and large intestines display distinct expression profiles of Bcl-2 homologs, known regulators of apoptosis. This is thought to indicate that control mechanisms of intestinal apoptosis are gut segment-specific. Little is known on the expression of Bcl-2 homologs during gut development. In man, intestinal features and functions are acquired largely by mid-gestation (18-20 wks); the question whether segment-specific controls of intestinal apoptosis are also acquired early during development remains open. In the present study, we approached this by investigating the expression of six Bcl-2 homologs (Bcl-2, Bcl-XL, Mcl- 1, Bax, Bak, Bad), and one nonhomologous associated molecule (Bag-1), during development of the human ileum and colon (12-20 wks of gestation). Beginning at 18 wks, we found that the epithelial localization of Bcl-2 homologs displayed differential patterns (or gradients) in both the ileum and colon; however, the patterns of some of the homologs differed between the two segrnents. For instance, Bag-1 and Bcl-2 exhibited crypt-villus decreasing gradients of expression in the ileum but not in the colon, whereas Mcl-1 displayed differing compartimentalizations between the two segments. Further analyses indicated that the steady-state expression levels of Bcl-2 homologs underwent modulations between 12 and 20 wks; however, the obsewed developmental profiles contrasted significantly between the two segments. For example, Bcl-2, Bag-1 and Bak levels increased in the colon, but the levels of these same homo.logs decreased in the ileum. Furthermore, by 18-20 wks, we found that the expression levels of each Bcl-2 homolog analyzed differed greatly between the ileum and colon. Altogether, these data indicate that the expression of Bcl-2 homologs is modulated differentially during human gut development in order to establish, by midgestation, distinct expression profiles for the small and large intestines. This in turn suggests that gut segmentspecific control mechanisms of human intestinal apoptosis are acquired early during fetal life.
Open Access
Gut glycoconjugates in Sparus aurata L. Pisces, Teleostei. A comparative histochemical study in larval and adult ages
(Murcia : F. Hernández, 1998) Domeneghini, C.; Pannelli Straini, R.; Veggetti, A.
This study examined the gut of the euryaline fish Sparus aurata, from the pharynx to the rectum. The specimens were collected from adult animals, both sexes, and several larval and juvenile stages, from 4 to 135 days of age. Histochemical methods to distinguish neutral and acidic glycoconjugates, as well as specific techniques to identify acidic glycoconjugates which contained 0-acylated sialic acids were used. The presence and distribution of sugar residues in the oligosaccharide side chain of glycoconjugates were investigated with the use of biotinylated lectins. The pharynx and oesophagus of adult fishes showed the presence of abundant secretory cells which synthesized a large quantity of neutral, as well as sulphated and sialylated glycoconjugates, with different cellular combinations of them in the proximal and distal tract. This may be related to the complex functions carried out by this end of the gut in a marine euryaline fish. Epithelia1 secretory cells were found in the developing oesophagus during larval life (14 days) earlier than in the stomach and intestine (34 days). The simple columnar epithelium that lined the gastric mucosa of adult fish synthesized a mixture of neutral and acidic glycoconjugates, whereas during larval life it was shown to contain neutral glycoconjugates only. The intestinal goblet cells were shown to secrete both neutral and acidic glycoconjugates, especially sulphated forms. The adherent mucus gel of the gastric and intestinal mucosa contained many sugar residues, as revealed by lectin histochemistry. This work clearly demonstrates that the quality of gut mucosubstances varies in different ages and in regions of the fish alimentary canal. This is possibly caused by changes in environmental conditions and may in turn sustain functional alterations of the digestive apparatus.
Open Access
Milk fat globule membrane plus milk fat increase docosahexaenoicacid availability in infant formulas
(2022-10-25) Gazquez Garcia, A.; Sabater Molina, María; Domínguez-lópez, I.; Sanchez-campillo Muñoz, M.; Torrento, N.; Tibau, J.; Moreno-muñoz, J. A.; Rodríguez-palmero, M.; López-sabater, M. C.; Larque Daza, E.; Fisiología
Purpose Milk fat globule membrane (MFGM) has components with emulsifer properties that could afect the provision of substrates to the brain. We evaluated the efects of MFGM plus milk fat addition to infant formulas on docosahexaenoic acid (DHA) availability and gut development. Methods In Experiment 1, suckling piglets were divided into 3 groups: Group L1 (n=8): fed with a vegetal fat formula with palm oil; L2 (n=8): canola oil formula and L3 (n=8): milk fat+canola oil+1% Lacprodan (3% MFGM of total protein content). In Experiment 2, Group L4 (n=7): fed with canola oil+1% Lacprodan (3% MFGM) and Group L5 (n=5): milk fat+canola oil+2% Lacprodan (6% MFGM). All formulas contained 0.2% DHA and 0.2% arachidonic acid. Results In Experiment 1, DHA was similar among the groups in both total fatty acids and plasma phospholipids (PL). However, 3% MFGM (L3) increased signifcantly the proportion of DHA and LC-PUFA n-3 in liver total fatty acids, jejunum, and also in jejunum PL respect to the other formulas. There were no changes in gut histology, cell proliferation, apoptosis, or brain DHA content. In Experiment 2, higher MFGM dose was used. Then, higher DHA was not only found in peripheral tissues of 6% MFGM (L5) piglets but also in plasma PL, while a similar trend was observed in cortex PL (p=0.123). Conclusion In conclusion, MFGM plus milk fat may increase DHA availability of infant formulas which could contribute to their benefcial health efects.
Open Access
Ultrastructural features of the gut in the white sturgeon, Acipenser transmontanus
(Murcia : F. Hernández, 2000) Radaelli, G.; Domeneghini, C.; Arrighi, S.; Francolini, M.; Mascarello, F.
Electron-microscopic examinations of the sturgeon gut were performed. Oesophageal goblet cells were abundant in the stratified epithelium. The ultrastructural features of the secretory granules of the oesophageal and intestinal goblet cells were quite similar to those of other vertebrates. Lobules of multilocular adipose tissue were observed in the deep tunica propriasubmucosa of the oesophagus, in close association with vasculature and large fibre bundles of myelinated and unmyelinated axons. Similarly composed nerve fibre bundles were observed in the cardiac stomach. too. The presence of myelinated axons is an unusual feature in the vertebrate enteric nervous system. Cardiac and fundic zones of the stomach showed an epithelium with columnar ciliated and non-ciliated cells, the latter equipped with fuzzy microvilli. Cells lining the tubular gastric proper glands were markedly granulated. Intestinal superficial epithelium was columnar and contained ciliated, as well as non-ciliated and goblet cells. In the tunica propria all over the intestine, the presence and ultrastructure of granulated cells was in addition described. Intraepithelial granulated leukocytes were seen throughout the alimentary canal. Various types of endocrine cells were seen both in the stomach and in the intestine, the size of their granules was measured and their ultrastructure described and compared to that of mammalian cell types.

Browsing by Subject "Gut"

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