AUTHOR=Sun Hongzhao , Ding Haikun , Shi Yuan , Li Chenyu , Jin Haoran , Yang Xiaoyue , Chen Zhaosong , Tian Pengpeng , Zhu Jianping , Sun Haiji 

TITLE=Exogenous Hydrogen Sulfide Within the Nucleus Ambiguus Inhibits Gastrointestinal Motility in Rats

JOURNAL=Frontiers in Physiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2020.545184

DOI=10.3389/fphys.2020.545184

ISSN=1664-042X

ABSTRACT=<p>Hydrogen sulfide (H<sub>2</sub>S) is a neuromodulator in the central nervous system. However, the physiological role of H<sub>2</sub>S in the nucleus ambiguus (NA) has rarely been reported. This research aimed to elucidate the role of H<sub>2</sub>S in the regulation of gastrointestinal motility in rats. Male Wistar rats were randomly assigned to sodium hydrosulfide (NaHS; 4 and 8 nmol) groups, physiological saline (PS) group, capsazepine (10 pmol) + NaHS (4 nmol) group, L703606 (4 nmol) + NaHS (4 nmol) group, and pyrrolidine dithiocarbamate (PDTC, 4 nmol) + NaHS (4 nmol) group. Gastrointestinal motility curves before and after the injection were recorded using a latex balloon attached with a pressure transducer, which was introduced into the pylorus through gastric fundus. The results demonstrated that NaHS (4 and 8 nmol), an exogenous H<sub>2</sub>S donor, remarkably suppressed gastrointestinal motility in the NA of rats (<italic>P</italic> &lt; 0.01). The suppressive effect of NaHS on gastrointestinal motility could be prevented by capsazepine, a transient receptor potential vanilloid 1 (TRPV1) antagonist, and PDTC, a NF-κB inhibitor. However, the same amount of PS did not induce significant changes in gastrointestinal motility (<italic>P</italic> &gt; 0.05). Our findings indicate that NaHS within the NA can remarkably suppress gastrointestinal motility in rats, possibly through TRPV1 channels and NF-κB-dependent mechanism.</p>