peptide-yy and Starvation

Refeeding starved rats with a fibre free 'elemental' diet increased crypt cell production rate (CCPR) in the proximal small intestine but not in the distal regions of the gut. Little effect on CCPR was seen when inert bulk (kaolin) was added to the 'elemental' diet. Addition of a poorly fermentable dietary 'fibre' (purified wood cellulose) had little effect on intestinal epithelial cell proliferation except in the distal colon where it significantly increased CCPR. A more readily fermentable 'fibre' (purified wheat bran) caused a large proliferative response in the proximal, mid and distal colon and in the distal small intestine. A gel forming 'fibre' also stimulated proliferation in the distal colon. There was no significant correlation between CCPR and plasma gastrin concentrations, but plasma enteroglucagon concentrations were significantly correlated with CCPR in almost all the sites studied. Plasma PYY concentrations also showed some correlation with CCPR, especially in the colon. Thus, whilst inert bulk cannot stimulate colonic epithelial cell proliferation, fermentable 'fibre' is capable of stimulating proliferation in the colon, and especially in the distal colon: it can also stimulate proliferation in the distal small intestine and it is likely that plasma enteroglucagon may have a role to play in this process.

Topics: Animals; Cell Division; Colon; Dietary Fiber; Epithelial Cells; Food, Formulated; Gastrins; Gastrointestinal Hormones; Glucagon-Like Peptides; Intestine, Small; Male; Peptide YY; Peptides; Rats; Rats, Inbred Strains; Starvation

Gastrointestinal (GI) peptide hormones, ghrelin (GHRL), cholecystokinin (CCK), and peptide YY (PYY) genes were identified in Atlantic salmon, Salmo salar. Full-length cDNAs encoding two isoforms of GHRL (GHRL-1 and GHRL-2), two isoforms of CCK (CCK-L and CCK-N) and peptide YY (PYY) cDNA were obtained. The GHRL-1 and GHRL-2 genes encoded proteins of 111- and 108-amino acids, respectively. Both types of GHRL were mainly expressed in the stomach, but also weakly expressed in the pyloric caeca, mid-gut, adipose tissue, and testis. The CCK-L and CCK-N genes encoded preproproteins of 132- and 140-amino acids, respectively. Both types of CCK were strongly expressed in the brain and comparatively weakly expressed in other tissues, including the digestive tract. In the digestive tract, CCK-L was mainly expressed in the pyloric caeca and hind-gut, while CCK-N was only expressed in the pyloric caeca. The PYY gene encoded for 97-amino acid residues and was mainly expressed in the brain and anterior part of the intestine, including the pyloric caeca. In an experiment, we demonstrated that 6 days starvation led to, increased GHRL-1 mRNA levels in the GI tract (stomach), while there no significant changes in expression levels for the other hormones in the GI tract. This suggests an orexigenic role for GHRL-1 in Atlantic salmon. These data contribute to elucidate the functional relationships among teleost gastrointestinal peptide hormones.

Topics: Amino Acid Sequence; Animals; Base Sequence; Cholecystokinin; Cloning, Molecular; DNA, Complementary; Fish Proteins; Ghrelin; Molecular Sequence Data; Peptide YY; Phylogeny; Salmo salar; Sequence Alignment; Sequence Analysis, DNA; Sequence Analysis, Protein; Starvation

Gastrointestinal hormones control gut functions in response to enteral nutrition. Diseases involving the gastrointestinal tract, such as necrotizing enterocolitis, may affect gut hormone secretion and therefore influence gut functions. Because bowel rest is an important part of the treatment, infants with this disease are especially at risk for an altered gut hormone secretion and thus for compromised gut functions.. In the current study, the gastrointestinal hormone profiles of eight preterm infants with an ileostomy after necrotizing enterocolitis (Bell stages 2 and 3) were evaluated during starvation and reintroduction of enteral nutrition. Basal and postprandial plasma concentrations of gastrin, cholecystokinin, and peptide YY were measured with sensitive and specific radioimmunoassays. The results were compared with those of 11 controls.. In the patients and the controls, plasma concentrations of all hormones were higher postprandially. The increases in cholecystokinin and peptide YY were significant in the patients. Compared with the controls, all concentrations were higher in the patients, and changes were significant for basal and postprandial cholecystokinin and postprandial peptide YY.. Enteral nutrition stimulates the secretion of gastrointestinal hormones, also in premature infants with a diseased distal small bowel and colon, as in necrotizing enterocolitis. The postprandial increase of peptide YY in patients with an ileostomy indicates that enteral substrate in the colon is not necessary for stimulation of peptide YY secretion.

Topics: Cholecystokinin; Enteral Nutrition; Enterocolitis, Necrotizing; Gastrins; Gastrointestinal Hormones; Humans; Ileostomy; Infant, Newborn; Infant, Premature; Infant, Premature, Diseases; Peptide YY; Postprandial Period; Radioimmunoassay; Starvation