Contraction induced by glicentin on smooth muscle cells from the human colon is abolished by exendin (9-39).

Unlabelled: Glicentin and glucagon-like peptide-1 (7-36) amide (GLP-1) are gut hormones released during digestion. Glicentin and GLP-1 slow down gastric emptying and glicentin can switch off the duodenojejunal fed motor pattern. The effect of glicentin on the motor activity of colon has never been reported in humans.

Oxyntomodulin and glicentin are potent inhibitors of the fed motility pattern in small intestine.

Glicentin (GLIC) and oxyntomodulin (OXM or GLIC 33-69) are gut hormones which regulate digestion. They are known to reduce digestive secretions and to delay gastric emptying. Their biological activities on intestinal motility are still unknown.

Cultured gastrointestinal smooth muscle cells: cell response to contractile agonists depends on their phenotypic state.

In the digestive tract, the transit of ingested food induces a local contraction-relaxation reflex of which the smooth muscle cell (SMC) represents the functional unit. Although freshly isolated SMCs have been extensively used for in vitro studies, in specific cases cultured cells appear necessary. Because conventionally cultured SMCs lose their contractile properties, we have developed: (1) differentiated, contractile rabbit gastric SMCs (D-stim cells), cultured in a medium supplemented with insulin, and (2) proliferative, dedifferentiated rabbit gastric SMCs (P-stim cells), cultured in a medium supplemented with insulin, fetal serum, EGF and b-FGF.

Oxyntomodulin inhibits pancreatic secretion through the nervous system in rats.

Glicentin (GLIC), oxyntomodulin (OXM), and peptide YY (PYY) released in blood by ileocolonic L-cells after meals may inhibit pancreatic secretion. Whereas OXM interacts with glucagon and tGLP-1 receptors, OXM 19-37, a biologically active fragment, does not. The purpose of this study was to measure the effect of OXM, OXM 19-37, GLIC, tGLP-1, and PYY on pancreatic secretion stimulated by 2 deoxyglucose (2DG), electrical stimulation of the vagus nerves (VES), acetylcholine and cholecystokinin octapeptide (CCK8) in anesthetized rats.

Glicentin and oxyntomodulin modulate both the phosphoinositide and cyclic adenosine monophosphate signaling pathways in gastric myocytes.

We have investigated the transduction pathways mediating the contractile effect of two glucagon-containing peptides, glicentin (GLIC) and oxyntomodulin (OXM), on smooth muscle cells isolated from rabbit antrum. Low concentrations of GLIC induced a biphasic and rapid (first phase at 5-8 sec) Ins(1,4,5)P3 production. By comparison, higher concentrations of OXM or OXM(19-37) were required to obtain biphasic time-courses of Ins(1,4,5)P3 production.

Oxyntomodulin reduces hydromineral transport through rat small intestine.

Glicentin (GLIC) and oxyntomodulin (OXM) are released from the ileum and colon during digestion. Both hormones reduce fluid and proton secretion in the stomach. The luminal concentration of sodium and chloride underlying the nutrient absorption, the effect of OXM on electrolyte transport through the small intestine, was assessed in vivo using ligated loops and in vitro using Ussing chambers.

Effect of glicentin, oxyntomodulin and related peptides on isolated gastric smooth muscle cells.

Glicentin (proglucagon 1-69 GLIC) and oxyntomodulin (proglucagon 33-69 or OXM) are two peptide hormones that are co-released from ileum and large intestine during digestion. They modulate in vivo gastric acid secretion and the gastro-pyloro-duodenal activity. The specificity of their effects is linked to the presence of their C-terminal octapepide.

H-Lys-Arg-Asn-Lys-Asn-Asn-OH is the minimal active structure of oxyntomodulin.

Oxyntomodulin inhibits gastric acid secretion via its C-terminal octapeptide. Its minimal active structure was delineated by testing, on histamine-stimulated gastric acid secretion in the conscious rat, the inhibitory effect of octapeptide analogues, shortened either or both on their N- or C- terminus. The octapeptide may be simplified by deleting the two C-terminal amino acids while keeping its efficacy and the slope of the dose-response curve.

Activity of oxyntomodulin on gastric acid secretion induced by histamine or a meal in the rat.

Conscious rats with chronic gastric fistula were trained for drinking a 14-ml milk meal. The activity of an intestinal hormone, oxyntomodulin (OXM), was studied in this model and compared to that observed when histamine was the stimulus. Under histamine (0.

Inhibition of gastric acid secretion by oxyntomodulin and its 19-37 fragment in the conscious rat.

Oxyntomodulin (Oxm) is a hormone, released from the intestine during digestion. Its target tissue is the gastric mucosa, where it inhibits acid secretion. It contains the 29-amino acid glucagon moiety, extended at its COOH-terminal end by an octapeptide.

Characterization of binding sites for oxyntomodulin on a somatostatin-secreting cell line (RIN T3).

Oxyntomodulin (OXM), a glucagon-containing peptide extended at its C-terminal end by an octapeptide, is a potent inhibitor of gastric acid secretion in rat and man. OXM appears to act on gastric mucosa at least partially through a stimulation of gastric somatostatin release. We have investigated the effects of OXM on a somatostatin-secreting cell line (RIN T3) derived from a radiation-induced rat insulinoma and characterized specific binding sites for this peptide.

N-acetyl oxyntomodulin30-37: pharmacokinetics and activity on gastric acid secretion.

Oxyntomodulin, an intestinal hormone which inhibits gastric acid secretion, is composed of glucagon and a C-terminal octapeptide. This octapeptide mimics the biological activity of the hormone. We have studied the activity of the N-acetyl octapeptide, partially protected against enzymatic degradation, on pentagastrin-, histamine- and milk meal-stimulated secretion in conscious rats and compared it to that of oxyntomodulin and its derivatives.

Oxyntomodulin and related peptides control somatostatin secretion in RIN T3 cells.

We studied the effects of oxyntomodulin (OXM), of its C-terminal (19-37) fragment (OXM (19-37)) and of glucagon (GLU) on somatostatin release, cyclic AMP accumulation and inositol phosphate turnover in somatostatin-secreting RIN T3 cells in culture. Rapid changes in cellular free Ca2+ were also measured using fura-2. Carbachol was used as a control test agent for the parameters involving the inositol phosphate/Ca2+ cascade.

Oxyntomodulin and its (19-37) and (30-37) fragments inhibit histamine-stimulated gastric acid secretion in the conscious rat.

Oxyntomodulin, a hormone released from jejuno-ileum and composed of the glucagon sequence extended by a C-terminal octapeptide displays original tissue specificity for the gastric mucosa. The aim of this study was to compare the effect of oxyntomodulin on histamine (0.4 mg/kg per h)-stimulated gastric acid secretion in the conscious rat to that of three of its fragments: oxyntomodulin-(19-37) produced from oxyntomodulin by enzymatic cleavage, oxyntomodulin-(30-37) corresponding to the molecular difference between oxyntomodulin and glucagon and oxyntomodulin-(32-37) produced during proglucagon processing to glucagon.

Solid-phase peptide synthesis of human(Nle-27)-oxyntomodulin. Preliminary evaluation of its biological activities.

Oxyntomodulin is a peptide isolated from porcine intestine which consists of the whole glucagon sequence extended at its C-terminal part by a basic octapeptide. The analogue (Nle-27)-oxyntomodulin of the human sequence has been synthesized by solid-phase peptide synthesis, purified by HPLC and identified. Its biological activities are the same as those of the natural hormone.

Oxyntomodulin and its C-terminal octapeptide inhibit liquid meal-stimulated acid secretion.

Oxyntomodulin (OXM), a 37-amino acid glucagon-containing peptide produced mainly in intestine and endocrine pancreas, is present in rat plasma and inhibits pentagastrin-stimulated gastric acid secretion in both the anesthetized and the conscious rat. In order to investigate the modifications in acid and water secretions in a physiological model, we set up a protocol which allowed us to study acid secretion in the conscious rat both under basal conditions (during an 18-hour fast) or after a physiological stimulus (a liquid meal). OXM (110 pmol X kg-1) did not modify the basal acid or water output in an 18-hour fasting state.

The biological significance of "enteroglucagon." Present status.

"Enteroglucagon" refers to glucagon-like peptides present in intestine that cross react with N-terminally directed antiglucagon antisera but not with C-terminally directed antisera. Two peptides having these features have been isolated from the lower small intestine: glicentin (69 amino acids) and oxyntomodulin (37 amino acids). The sequence of the pancreatic preproglucagon gene suggests that glucagon, glicentin and oxyntomodulin derive from the same translational pathway, each individual peptide being produced by different posttranslational processing.

Synthesis of the C-terminal octapeptide of pig oxyntomodulin. Lys-Arg-Asn-Lys-Asn-Asn-Ile-Ala: a potent inhibitor of pentagastrin-induced acid secretion.

The synthesis of Lys-Arg-Asn-Lys-Asn-Asn-Ile-Ala representing the C-terminal octapeptide of oxyntomodulin isolated from pig intestine is described. Its structure was confirmed by its 360-MHz 1H NMR spectra. The octapeptide was tested for its ability to inhibit pentagastrin-induced acid secretion, in the anaesthetized rat, in the conscious rat with chronic gastric fistula, and in the conscious cat with gastric chronic fistula.

Oxyntomodulin (glucagon-37) and its C-terminal octapeptide inhibit gastric acid secretion.

Oxyntomodulin (OXM) is a peptide isolated from porcine intestine which consists of the whole glucagon sequence with a basic octapeptide (KA8) at its C-terminal end. In this study, the effect of OXM and KA8 on pentagastrin-stimulated gastric acid secretion has been studied in conscious rats and cats. In rats, OXM (25-450 pmol .

Chemical specificity of the effects of branched chain amino acids on glucagon and insulin release in the suckling rat.

The work presented here aims at investigating the in vitro relationship between amino acids and pancreatic hormonal release in the suckling rat. Among the 20 most usual amino acids, 12 of them were tested on perifused pieces of pancreas in 5.5-day-old rats at a low glucose concentration.

A pure enteroglucagon, oxyntomodulin (glucagon 37), stimulates insulin release in perfused rat pancreas.

Oxyntomodulin, a gut peptide recently purified, has been tested in isolated perfused pancreases of normal rats. It was shown to stimulate insulin release monophasically in the presence of a low (6 mM) glucose concentration in the medium. Furthermore, oxyntomodulin potentiated glucose-induced insulin release (10 mM glucose) in a dose-dependent manner, although it was less powerful in this respect than equimolar concentrations of pancreatic glucagon.

Portal insulin and glucagon in rats fed proteins as a meal: immediate variations and circadian modulations.

In adult rats, proteins fed as a meal apart from the remainder of the diet induce alterations of protein metabolism characterized by the simultaneous stimulation of protein synthesis and breakdown. These alterations occur in parallel with an acceleration of glycogenolysis. The purpose of this work was to investigate whether these metabolic changes are related to variations in portal insulin and glucagon levels or to insulin-glucagon balance.

Regulation of insulin biosynthesis in vivo by glucose in the newborn rat.

The effects of glucose on insulin biosynthesis in vivo were investigated in the 3-day-old rat. The extent of insulin synthesized was determined by following the incorporation of 3H-leucine into immunoreactive insulin (3H-IRI) and pancreatic proteins (3H-PROT). Blood glucose levels increased 2.