Effects of several denervation procedures on distribution of calcitonin gene-related peptide and substance P immunoreactive in rat stomach.
The effect of chemical deafferentation, vagotomy (VGX), and gangliosympathectomy (GSX) on the density of fibers containing calcitonin gene-related peptide (CGRP) and substance P (Sub.P) in the rat gastric wall was studied. Chemical deafferentation by capsaicin abolished the density of CGRP-immunoreactive (IR) fibers, not Sub.P-IR fibers. Ten days after VGX, the density of CGRP-IR or Sub.P-IR fibers in the mucosa was largely reduced, while no reduction of CGRP-IR and Sub.P-IR fibers was seen in submucosal and muscular layers. GSX significantly reduced the density of CGRP-IR fibers in the mucosa and caused a moderate decrease in the fibers in submucosal and muscular layers. Pretreatment with 6-hydroxydopamine, a neurotoxin for noradrenergic nerves, did not affect the density of CGRP-IR fibers in the gastric wall. The density of Sub.P-IR fibers in the gastric wall was not affected by GSX. These studies indicate that the CGRP-IR and Sub.P-IR fibers in the mucosa are susceptible to extrinsic nerve denervation compared with those in the submucosa and muscle layers, that a major portion of the CGRP-IR fibers in the mucosa is of both vagal and spinal origin, and that a major portion of the Sub.P-IR fibers in the mucosa is of vagal origin. Furthermore, the present results support that CGRP-IR fibers, not Sub.P-IR fibers, in the rat stomach are capsaicin-sensitive.
Suzuki
T
T
Department of Clinical Pharmacology, School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan.
Kagoshima
M
M
Shibata
M
M
Inaba
N
N
Onodera
S
S
Yamaura
T
T
Shimada
H
H
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis*; D002211:Capsaicin; D005753:Gastric Mucosa / Q000294:innervation* / Q000378:metabolism; D008297:Male; D009412:Nerve Fibers / Q000737:chemistry*; D016627:Oxidopamine; D051381:Rats; D017207:Rats, Sprague-Dawley; D013270:Stomach / Q000294:innervation*; D013373:Substance P / Q000032:analysis*; D013562:Sympathectomy; D013563:Sympathectomy, Chemical; D014628:Vagotomy
D013373:Substance P; D016627:Oxidopamine; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin