Functional mapping of NPY/PYY receptors in rat and human gastro-intestinal tract.
Peptide YY (PYY) is involved in the regulation of several gastro-intestinal functions, including motility. The aims of the present study were (i) to characterize the effects of PYY on smooth muscle strips obtained from the different gastro-intestinal segments in rats and in humans and (ii) to realize a map of the Y receptors expression. Contractions of strips were recorded under isometric conditions, using PYY and acetylcholine as control. We observed that PYY induced a contraction of muscle strips from rat proximal colon, but displayed no effect on other gut segments. Using RT-PCR, mRNA encoding the Y1 and Y4 receptors were detected in muscle strips depending on the segment. In humans, the muscle preparations responded to ACh but not to PYY. Moreover, only Y2 receptor mRNA was found in the ileum and the left colon, but not in other segments. Our study shows the heterogeneity in the expression of Y receptors along the gastro-intestinal tract, and reveals great discrepancies between rats and humans both concerning the expression of Y receptor, and the response of smooth muscle strips to PYY.
Ferrier
Laurent
L
Centre de Recherche en Nutrition Humaine, INSERM U539, CHU-Hôtel Dieu, 44093 Nantes, France. ferrier@toulouse.inra.fr
Segain
Jean-Pierre
JP
Bonnet
Christian
C
Cherbut
Christine
C
Lehur
Paul-Antoine
PA
Jarry
Anne
A
Galmiche
Jean-Paul
JP
Blottiere
Hervé M
HM
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D003106:Colon / Q000187:drug effects / Q000502:physiology; D004064:Digestive System / Q000033:anatomy & histology / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005769:Gastrointestinal Motility / Q000502:physiology; D015870:Gene Expression; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D019894:Peptide YY / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011964:Receptors, Gastrointestinal Hormone / Q000502:physiology*; D017476:Receptors, Neuropeptide Y / Q000145:classification / Q000235:genetics / Q000502:physiology*
D012333:RNA, Messenger; D011964:Receptors, Gastrointestinal Hormone; D017476:Receptors, Neuropeptide Y; C082172:peptide YY receptor; D019894:Peptide YY; D000109:Acetylcholine