Gastric distention enhances FOS and calcitonin gene-related peptide expression in the spinal cord and brain of rats.
OBJECTIVE
The purpose of this study was to determine the pathway and mode of transmission of visceral stimuli by investigating the distribution of the FOS and calcitonin gene-related peptide (CGRP) proteins in the central nervous system.


METHODS
Twenty-four Sprague-Dawley rats were divided into three groups: study group (n = 12), sham control group (n = 6), and normal control group (n = 6). A balloon was implanted into the stomach of the rats in the study and sham control groups. After 48 h, the rats in the study group had the stomach distended (80 mmHg) for 2 h, after which they were killed and the antrum, thoracic spinal cord and brain were isolated or dissected. The expression of Fos and CGRP in these tissues was detected immunohistochemically.


RESULTS
FOS expression in the dorsal horn of the spinal cord, dorsal nucleus of the vagal nerve, nucleus of the solitary tract in the study rats was significantly higher than in the sham and normal controls. However, no difference was found between the three groups in FOS expression in the myenteric plexus. Similarly, gastric distention enhanced CGRP expression significantly in the spinal cord and medulla oblongata and correlated closely with FOS expression in these two areas.


CONCLUSIONS
Gastric distention can activate the limbic system, and CGRP plays an important role in the input of visceral stimuli.
Zhang
Fei Fei
FF
Department of Gastroenterology, Shanghai Armed Police Hospital, Shanghai, China.
Mo
Jian Zhong
JZ
Chen
Xiao Yu
XY
Peng
Yan Shen
YS
Chen
Sheng Liang
SL
Xiao
Shu Dong
SD
D000818:Animals; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism*; D013271:Gastric Dilatation / Q000378:metabolism*; D007150:Immunohistochemistry; D008032:Limbic System / Q000502:physiology; D008297:Male; D023421:Models, Animal; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000378:metabolism* / Q000473:pathology
D016760:Proto-Oncogene Proteins c-fos; D015740:Calcitonin Gene-Related Peptide