Neuromedin U receptor 1 expression in the rat endocrine pancreas and evidence suggesting neuromedin U suppressive effect on insulin secretion from isolated rat pancreatic islets.
Neuromedin U (NmU) is a regulatory peptide found in significant concentrations in both the brain and gut of the rat and is named according to its ability to powerfully contract the uterus. Two types of NmU receptors were recently identified and subsequent studies evidenced NmU involvement in the regulation of energy homeostasis. Such a role of neuromedin U suggests that a polypeptide may also be involved in the regulation of adipoinsular axis function. Therefore in the present study we examined the expression of NmU receptors in pancreatic islets using RT-PCR and Western blotting analysis. We also investigated the role of NmU in regulation of insulin secretion in vitro using isolated pancreatic islets. We have confirmed that NmUR1 but not NmUR2 is specifically expressed in isolated rat pancreatic islets. In all tested doses (1, 10, 100 nmol/l) NmU dose- dependently decreased insulin output by isolated pancreatic islets. These inhibitory effects of NmU on insulin secretion may suggest the involvement of NmU in regulating the pancreatic branch of adipoinsular axis function. Thus, NmU can be included in that group of anorectic peptides, which are also involved in the regulation of insulin secretion.
Kaczmarek
Przemyslaw
P
Department of Animal Physiology and Biochemistry, August Cieszkowski University of Agriculture, 60-637 Poznan, Poland. przekacz@au.poznan.pl
Malendowicz
Ludwik K
LK
Pruszynska-Oszmalek
Ewa
E
Wojciechowicz
Tatiana
T
Szczepankiewicz
Dawid
D
Szkudelski
Tomasz
T
Nowak
Krzysztof W
KW
D000818:Animals; D001067:Appetite Depressants / Q000494:pharmacology*; D015153:Blotting, Western; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism*; D007329:Insulin Antagonists / Q000494:pharmacology*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects* / Q000378:metabolism; D008565:Membrane Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D009479:Neuropeptides / Q000494:pharmacology* / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D051381:Rats; D017981:Receptors, Neurotransmitter / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D001067:Appetite Depressants; D007328:Insulin; D007329:Insulin Antagonists; D008565:Membrane Proteins; D009479:Neuropeptides; D012333:RNA, Messenger; D017981:Receptors, Neurotransmitter; C082444:neuromedin U receptor; C056900:neuromedin U