Effects of Exogenous Hydrogen Sulfide in the Hypothalamic Paraventricular Nucleus on Gastric Function in Rats

Abstract

Background: Hydrogen sulfide (H2S) is a new type of gas neurotransmitter discovered in recent years. It plays an important role in various physiological activities. The hypothalamus paraventricular nucleus (PVN) is an important nucleus that regulates gastric function. This study aimed to clarify the role of H2S in the paraventricular nucleus of the hypothalamus on the gastric function of rats.Methods: An immunofluorescence histochemistry double-labelling technique was used to determine whether cystathionine-beta-synthase (CBS) and c-Fos neurons are involved in PVN stress. Through microinjection of different concentrations of NaHS, physiological saline (PS), D-2-Amino-5-phosphonovaleric acid (D-AP5), and pyrrolidine dithiocarbamate (PDTC), we observed gastric motility and gastric acid secretion.Results: c-Fos and CBS co-expressed the most positive neurons after 1 h of restraint and immersion, followed by 3 h, and the least was at 0 h. After injection of different concentrations of NaHS into the PVN, gastric motility and gastric acid secretion in rats were significantly inhibited and promoted, respectively (p < 0.01); however, injection of normal saline, D-AP5, and PDTC did not cause any significant change (p > 0.05). The suppressive effect of NaHS on gastrointestinal motility and the promotional effect of NaHS on gastric acid secretion could be prevented by D-AP5, a specific N-methyl-D-aspartic acid (NMDA) receptor antagonist, and PDTC, an NF-κB inhibitor.Conclusion: There are neurons co-expressing CBS and c-Fos in the PVN, and the injection of NaHS into the PVN can inhibit gastric motility and promote gastric acid secretion in rats. This effect may be mediated by NMDA receptors and the NF-κB signalling pathway.

Investigating the L-Glu-NMDA receptor-H2S-NMDA receptor pathway that regulates gastric function in rats’ nucleus ambiguus

“…H 2 S has been reported to exert anti-apoptotic and anti-inflammatory effects in the nervous system, so its effects on physiological systems such as nerves cannot be ignored Kida and Ichinose (2015) . We did a dose-dependent search in previous experiment and found that 2 nmol of NaHS had the greatest effect on gastric function, so we chose 2 nmol Li et al (2021) . Injection of the NMDA receptor blocker, D-AP5, attenuates the gastric mucosal damage caused by restraint water-immersion stress Landeira-Fernandez (2015) .…”

Effect of exogenous hydrogen sulfide in the nucleus tractus solitarius on gastric motility in rats

“…Our experiments revealed that the injection of the NF-κB pathway blocker PDTC followed by NaHS eliminated the modulation of gastric function by NaHS. H 2 S is mainly synthesized in the brain by the CBS enzyme, andwe found that NaHS injection in both the ambiguous and paraventricular nuclei inhibited gastric motility in rats via the NF-κB pathway[ 44 , 45 ], that the injection of NaHS to the brain blocked inflammation-associated apoptosis, and that treatment with NaHS reduced the expression of inflammatory factors in astrocytes and microglia due to Alzheimer’s disease[ 46 ]. H 2 S reduces the levels of phosphorylated p38 MAPK and phosphorylated p65 NF-κB in vivo .…”