Hydrogen sulfide in the nucleus tractus solitarii regulates gastric acid secretion in rats.

Hydrogen sulfide (H2S) is a neuromodulator in the central nervous system. The physiological function of H2S in the nucleus tractus solitarii (NTS) has rarely been reported. This research aimed to explore the role of H2S in regulating gastric functions. 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 (4 nmol) + NaHS (4 nmol) group. The pH values of gastric acid were measured using a pH meter pre- and post-injection. It was found that the microinjetion of NaHS (4 and 8 nmol), an exogenous H2S donor, into the NTS (n = 6) remarkably decreased the pH values of gastric juice. The inductive effect of NaHS on gastric juice production could be suppressed by capsazepine (a transient receptor potential vanilloid 1 antagonist), L703606 (a NK1 receptor antagonist) and pyrrolidine dithiocarbamate (a nuclear fator-κB inhibitor). However, the same amount of PS did not induce any significant change in the pH value of gastric acid (P > 0.05). The findings of this study revealed that NaHS within the NTS remarkably promoted gastric acid secretion via the activation of TRPV1 channels and nuclear factor-κB-dependent mechanism in rats.