Coexpression of glucagon-like peptide-1 (GLP-1) receptor, vasopressin, and oxytocin mRNAs in neurons of the rat hypothalamic supraoptic and paraventricular nuclei: effect of GLP-1(7-36)amide on vasopressin and oxytocin release.
This study was designed to gain better insight into the relationship between glucagon-like peptide-1 (GLP-1) (7-36) amide and vasopressin (AVP) and oxytocin (OX). In situ hybridization histochemistry revealed colocalization of the mRNAs for GLP-1 receptor, AVP, and OX in neurons of the hypothalamic supraoptic and paraventricular nuclei. To determine whether GLP-1(7-36)amide alters AVP and/or OX release, both in vivo and in vitro experimental study designs were used. In vivo, intravenous administration of 1 microg of GLP-1(7-36)amide into the jugular vein significantly decreased plasma AVP and OX concentrations. In vitro incubation of the neurohypophysis with either 0.1 or 1 microg of GLP-1(7-36)amide did not modify the release of AVP. However, addition of 1 microg of GLP-1(7-36)amide to the incubation medium increased slightly the secretion of OX. The coexpression of GLP-1 receptor and AVP mRNAs in hypothalamic supraoptic and paraventricular nuclei gives further support to the already reported central effects of GLP-1 (7-36)amide on AVP. Our findings also suggest a dual secretory response of AVP and OX to the effect of GLP-1 (7-36)amide, which most likely is related to the amount and/or the route of peptide administration.
Zueco
J A
JA
Department of Biochemistry and Molecular Biology, Faculty of Medicine, Complutense University, Madrid, Spain.
Esquifino
A I
AI
Chowen
J A
JA
Alvarez
E
E
Castrillón
P O
PO
Blázquez
E
E
D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects; D005934:Glucagon / Q000235:genetics*; D052216:Glucagon-Like Peptide 1; D004763:Glucagon-Like Peptides; D017403:In Situ Hybridization; D008297:Male; D009474:Neurons / Q000737:chemistry / Q000378:metabolism; D010121:Oxytocin / Q000235:genetics* / Q000378:metabolism; D010286:Paraventricular Hypothalamic Nucleus / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D010446:Peptide Fragments / Q000235:genetics* / Q000494:pharmacology*; D010902:Pituitary Gland / Q000378:metabolism; D011498:Protein Precursors / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013495:Supraoptic Nucleus / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D014667:Vasopressins / Q000235:genetics* / Q000378:metabolism
D010446:Peptide Fragments; D011498:Protein Precursors; D012333:RNA, Messenger; C061970:glucagon-like peptide 1 (7-36); D014667:Vasopressins; D010121:Oxytocin; D004763:Glucagon-Like Peptides; D052216:Glucagon-Like Peptide 1; D005934:Glucagon