Search results for "Intestin"

Expression and regulation of mPer1 in immortalized GnRH neurons.

2003

Hypothalamic GnRH (gonadotropin-releasing hormone) neurons play a critical role in the initiation and maintenance of reproduction competence. Using the mouse GnRH neuronal cell line, GT1-7, we have characterized the expression of the gene mPer1, a recognized key element of the mammalian circadian clockwork. Both mPer1 transcripts and the 136 kDa mPER1 gene product could be detected in these cells. Immunocytochemical analysis also confirmed expression of mPER1 both in vitro and in vivo in GnRH neurons. Activation of cyclic AMP signalling pathways in vitro elevated GnRH secretion as well as mPer1 expression and nuclear mPER1 immunoreactivity. As mPER1 is known to feedback on transcriptional a…

GLP-2 receptor expression in excitatory and inhibitory enteric neurons and its role in mouse duodenum contractility

2011

Background  Glucagon-like peptide 2 (GLP-2), a nutrient-responsive hormone, exerts various actions in the gastrointestinal tract that are mediated by a G-protein coupled receptor called GLP-2R. A little information is available on GLP-2R expression in enteric neurons and nothing on the interstitial cells of Cajal (ICC). Methods  We investigated presence and distribution of the GLP-2R in the mouse duodenum by immunohistochemistry and the potential motor effects of GLP-2 on the spontaneous and neurally evoked mechanical activity. Key Results  The GLP-2R was expressed by the myenteric and submucosal neurons. Labelling was also present in nerve varicosities within the circular muscular layer an…

Vulvar involvement in pediatric Crohn’s disease: a systematic review

2018

Purpose: The aim of the study is to report a systematic review (from 2000 to 2017) of all pediatric cases of vulvar Crohn’s disease (VCD) and to highlight the key-points for a correct diagnosis and management of this rare condition. Methods: An electronic search using the Pubmed/Medline, Scopus, EMBASE, Cochrane database and Google Scholar database was performed according to PRISMA guidelines. Results: Twenty pediatric studies and 22 cases of VCD were included for analysis. All the articles reported a single case, except two articles where two cases, respectively, are described. Clinical vulvar examination showed the following main manifestations: vulvar erythema (9/22 cases, 40.9%), vulv…

Glucagon-like peptide-1 relaxes gastric antrum through nitric oxide in mice.

2010

Abstract Glucagon-like-peptide-1 (GLP-1) is a proglucagon-derived peptide expressed in the intestinal enteroendocrine-L cells and released after meal ingestion. GLP-1 reduces postprandial glycemia not only by its hormonal effects, but also by its inhibitory effects on gastrointestinal motility. Recently, we showed that GLP-1 acts in the enteric nervous system of mouse intestine. Therefore our working hypothesis was that GLP-1 may have also a direct influence on the gastric mechanical activity since the major part of experimental studies about its involvement in the regulation of gastric motility have been conducted in in vivo conditions. The purposes of this study were (i) to examine exogen…

Relaxation induced by N-terminal fragments of chromogranin A in mouse gastric preparations.

2007

Abstract A definitive role for chromogranin A (CGA)-derived fragments in the control of the gastrointestinal smooth muscle contractility has not been yet established. The purpose of the present study was to evaluate, in vitro , the effects of the recombinant vasostatin 1–78 (VS-1), CGA 7–57 and CGA 47–66 on the mouse gastric mechanical activity, recording the changes of intraluminal pressure. VS-1, CGA 7–57 and CGA 47–66 produced concentration-dependent relaxations. Mouse anti-vasostatin-1 monoclonal antibody 5A8, recognising the region 53–57, abolished the relaxation induced by VS-1, indicating the specificity of the effect. The relaxation was significantly reduced by tetrodotoxin (TTX), b…

Regulation of serotonin release from the intestinal mucosa.

1991

Summary In the mammalian intestine serotonin (5-hydroxytryptamine, 5-HT) is present in high concentrations in the enterochromaffin cells. The release of 5-HT from the intestinal mucosa is regulated by a complex pattern of neuronal and humoral inputs to the enterochromaffin cells. The enterochromaffin cells appear to be endowed with different inhibitory ( α 2 -adrenoceptors, GABA A - and GABA B -receptors, histamine H 3 -receptors, receptors for vasoactive intestinal polypeptide and somatostatin) as well as stimulatory receptors ( β -adrenoceptors, muscarine and nicotine receptors). The physiological significance of this complex system of receptors is suggested by experiments which demonstra…

GABA and its receptors in the enteric nervous system of the gastrointestinal tract.

2009

Glucagon-Like Peptide-1 Modulates Neurally-Evoked Mucosal Chloride Secretion in Guinea Pig Small Intestine In Vitro.

2012

Glucagon-like peptide-1 (GLP-1) acts at the G protein-coupled receptor, GLP-1R, to stimulate secretion of insulin and to inhibit secretion of glucagon and gastric acid. Involvement in mucosal secretory physiology has received negligible attention. We aimed to study involvement of GLP-1 in mucosal chloride secretion in the small intestine. Ussing chamber methods, in concert with transmural electrical field stimulation (EFS), were used to study actions on neurogenic chloride secretion. ELISA was used to study GLP-1R effects on neural release of acetylcholine (ACh). Intramural localization of GLP-1R was assessed with immunohistochemistry. Application of GLP-1 to serosal or mucosal sides of fla…

GLP-2 receptor expression in excitatory and inhibitory enteric neurons and its role in mouse duodenum contractility.

2011

Background. Glucagon-like peptide 2 (GLP-2), a nutrient-responsive hormone, exerts various actions in the gastrointestinal tract that are mediated by a G-protein coupled receptor called GLP-2R. A little information is available on GLP-2R expression in enteric neurons and nothing on the interstitial cells of Cajal (ICC). Methods. We investigated presence and distribution of the GLP-2R in the mouse duodenum by immunohistochemistry and the potential motor effects of GLP-2 on the spontaneous and neurally evoked mechanical activity. Key Results. The GLP-2R was expressed by the myenteric and submucosal neurons. Labelling was also present in nerve varicosities within the circular muscular layer an…

In vitro glucuronidation of 7-hydroxycoumarin derivatives in intestine and liver microsomes of Beagle dogs

2019

Beagle dog is a standard animal model for evaluating nonclinical pharmacokinetics of new drug candidates. Glucuronidation in intestine and liver is an important first-pass drug metabolic pathway, especially for phenolic compounds. This study evaluated the glucuronidation characteristics of several 7-hydroxycoumarin derivatives in beagle dog's intestine and liver in vitro. To this end, glucuronidation rates of 7-hydroxycoumarin (compound 1), 7-hydroxy-4-trifluoromethylcoumarin (2), 6-methoxy-7-hydroxycoumarin (3), 7-hydroxy-3-(4-tolyl)coumarin (4), 3-(4-fluorophenyl)coumarin (5), 7-hydroxy-3-(4-hydroxyphenyl)coumarin (6), 7-hydroxy-3-(4-methoxyphenyl)coumarin (7), and 7-hydroxy-3-(1H-1,2,4-t…