Release of calcitonin gene-related peptide in guinea pig inferior mesenteric ganglion.
Neurons of the guinea pig IMG are surrounded by nerve fibers containing CGRP-like immunoreactivity (LI). The purpose of this study was to determine whether colonic distension releases CGRP-LI in the IMG and whether opioid peptides and neurotensin(8-13) [NT(8-13)] modulate its release. Colonic distension released CGRP-LI. Methionine-enkephalin acted through mu and/or delta receptors to block release. NT(8-13) had no effect on release of CGRP-LI. Capsaicin pretreatment reduced the content of CGRP-LI in the IMG by 37%. Colonic distension did not release CGRP-LI from capsaicin-insensitive fibers. The data suggest that colonic distension releases CGRP-LI material from capsaicin-sensitive nerves and that enkephalins modulate release of CGRP-LI.
Ma
R C
RC
Department of Physiology and Biophysics, Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA.
Szurszewski
J H
JH
D000344:Afferent Pathways / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism*; D002118:Calcium / Q000494:pharmacology; D002211:Capsaicin / Q000494:pharmacology; D003106:Colon / Q000294:innervation / Q000502:physiology; D004743:Enkephalin, Leucine / Q000494:pharmacology; D004744:Enkephalin, Methionine / Q000494:pharmacology; D005724:Ganglia / Q000187:drug effects / Q000378:metabolism*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D008643:Mesentery / Q000294:innervation*; D009411:Nerve Endings / Q000187:drug effects / Q000378:metabolism; D009496:Neurotensin / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology
D010446:Peptide Fragments; D009496:Neurotensin; D004744:Enkephalin, Methionine; D004743:Enkephalin, Leucine; C054381:neurotensin (8-13); D008274:Magnesium; D015740:Calcitonin Gene-Related Peptide; D011188:Potassium; D002211:Capsaicin; D002118:Calcium