CBS-Induced H2S Generation in Hippocampus Inhibits EA-Induced Analgesia.

Hydrogen sulfide (H2S) is an important mediator participating in both physiological and pathological systems and related to the inflammatory process. Acupuncture has a therapeutic effect on inflammatory pain. However, whether H2S generated in the central nervous system (CNS) is a mediator of electroacupuncture (EA) treatment for inflammatory pain is unknown. We injected complete Freund's adjuvant (CFA) to induce inflammatory pain and applied EA treatment as an interventional strategy for pain relief. The results presented here show that S-adenosyl-l-methionine (SAM), an allosteric activator of cystathionine-β-synthetase (CBS), may reverse the therapeutic effect of EA. CBS-induced H2S generation might get involved in the mechanism of EA-induced analgesia in the hippocampus on chronic inflammatory pain.