Different Regulation of Atrial ANP Release through Neuropeptide Y2 and Y4 Receptors

Neuropeptide Y (NPY) receptors are present in cardiac membranes. However, its physiological roles in the heart are not clear. The aim of this study was to define the direct effects of pancreatic polypeptide (PP) on atrial dynamics and atrial natriuretic peptide (ANP) release in perfused beating atria. Pancreatic polypeptides, a NPY Y4 receptor agonist, decreased atrial contractility but was not dose-dependent. The ANP release was stimulated by PP in a dose-dependent manner. GR 23118, a NPY Y4 receptor agonist, also increased the ANP release and the potency was greater than PP. In contrast, peptide YY (3-36) (PYY), an NPY Y2 receptor agonist, suppressed the release of ANP with positive inotropy. NPY, an agonist for Y1, 2, 5 receptor, did not cause any significant changes. The pretreatment of NPY (18-36), an antagonist for NPY Y3 receptor, markedly attenuated the stimulation of ANP release by PP but did not affect the suppression of ANP release by PYY. BIIE0246, an antagonist for NPY Y2 receptor, attenuated the suppression of ANP release by PYY. The responsiveness of atrial contractility to PP or PYY was not affected by either of the antagonists. These results suggest that NPY Y4 and Y2 receptor differently regulate the release of atrial ANP

Low Densities of Serotonin and Peptide YY Cells in the Colon of Patients with Irritable Bowel Syndrome

Background The gut hormones are important in regulating gastrointestinal motility. Disturbances in gastrointestinal motility have been reported in patients with irritable bowel syndrome (IBS). Reduced endocrine cell density, as revealed by chromogranin A, has been reported in the colon of IBS patients. Aims To investigate a possible abnormality in the colonic endocrine cells of IBS patients. Methods A total of 41 patients with IBS according to Rome Criteria III and 20 controls were included in the study. Biopsies from the right and left colon were obtained from both patients and controls during colonoscopy. The biopsies were immunostained for serotonin, peptide YY (PYY), pancreatic polypeptide (PP), entroglucagon, and somatostatin cells. Cell densities were quantified by computerized image analysis. Results Serotonin and PYY cell densities were reduced in the colon of IBS patients. PP, entroglucagon, and somatostatin- immunoreactive cells were too few to enable reliable quantification

LES RECEPTEURS INTESTINAUX DU PEPTIDE YY (PYY) ET DES PEPTIDES APPARENTES CHEZ LE RAT

ORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF

Chapter 32 - Human-Computer Interaction in Architectural Design

This chapter discusses human–computer interaction in architectural design. It focuses on two topics: (1) the role of graphic representations and, therefore, of computer graphics in the architectural design process; and (2) the role of internal representations and models in design cognition and value judgment. The availability of sophisticated, powerful, and inexpensive information technology has enabled considerable progress to be made in recent years in the development of computer systems for assisting the architectural design activity. Many systems, both in the US and in other countries, can presently address the information needs of building designers at various stages of the process, from facility programming and design to the management of both design and construction. A survey of architectural firms in the US carried out for the magazine Progressive Architecture indicated that in architecture, as in many other professions, the age of computers has truly arrived, with 95% of the sample having or planning to acquire some form of computer

Functional and Molecular Properties of the Human Recombinant Y4 Receptor: Resistance to Agonist-Promoted Desensitization 1

ABSTRACT I-hPP identified a single M r 60,000 glycosylated Y4 receptor; and 4) the natural peptides hPP, hPYY, and hNPY inhibited forskolin-stimulated cAMP production in clone 29 cells with EC 50 values of 0.56 nM, 218 nM, and Ͼ1 M, respectively. The inhibitory effect of hPP was abolished when cells were incubated with pertussis toxin, indicating a pertussis toxin-sensitive G i protein-mediated event. 5) Exposure of cells to 10 nM hPP for 24 h resulted in the absence of modification of binding capacity (1.38 versus 1.44 pmol/mg protein in control cells) or affinity (0.31 versus 0.26 nM in control cells); there also was no modification in the potency and efficacy of hPP in inhibiting forskolin-stimulated cAMP. Immunofluorescence indicated that the Y4 receptor was not internalized within the cells after 24-h treatment with 10 nM hPP. These data support that Y4 receptors are resistant to agonist-promoted desensitization and internalization. Clone 29 cells provide a valuable tool to further characterize the pharmacological aspects of human Y4 receptor