Expression and localization of c-Fos and NOS in the central nerve system following esophageal acid stimulation in rats.
OBJECTIVE
To determine the distribution of neurons expressing c-Fos and nitric oxide synthase (NOS) in the central nerve system (CNS) following esophageal acid exposure, and to investigate the relationship between c-Fos and NOS.


METHODS
Twelve Wistar rats were randomly divided into two equal groups. Hydrochloric acid with pepsin was perfused in the lower part of the esophagus for 60 min. As a control, normal saline was used. Thirty minutes after the perfusion, the rats were killed and brains were removed and processed for c-Fos immunohistochemistry and NADPH-d histochemistry. Blood pressure (BP), heart rate (HR), and respiratory rate (RR) during the experimental procedures were recorded every 10 min.


RESULTS
There were no significant differences in BP, HR and RR between the two groups. c-Fos immunoreactivity was significantly increased in rats receiving acid plus pepsin perfusion in amygdala (AM), paraventricular nucleus (PVN), parabrachial nucleus (PBN), nucleus tractus solitarius and dorsal motor nucleus of vagus (NTS/DMV), nucleus ambiguous (NA), reticular nucleus of medulla (RNM) and area postrema (AP). NOS reactivity in this group was significantly increased in PVN, PBN, NTS/DMV, RNM and AP. c-Fos and NOS had significant correlation between PVN, PBN, NTS/DMV, RNM and AP.


CONCLUSIONS
Acid plus pepsin perfusion of the esophagus results in neural activation in areas of CNS, and NO is likely one of the neurotransmitters in some of these areas.
Shuai
Xiao-Wei
XW
Department of Gastroenterology, First Hospital of Peking University, Beijing 100034, China.
Xie
Peng-Yan
PY
D000818:Animals; D001921:Brain / Q000378:metabolism*; D004947:Esophagus / Q000187:drug effects*; D006851:Hydrochloric Acid / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution
D016760:Proto-Oncogene Proteins c-fos; D019001:Nitric Oxide Synthase; D006851:Hydrochloric Acid