Hydrogen Sulfide Facilitates Carotid Sinus Baroreflex And Baroreceptor Activity In Anesthetized Male Rats

Hydrogen sulfide (H₂S) has been generally considered as a toxic gas found in the contaminated environment. Its major toxic effects are the toxication of central nervous system and the inhibition of the respiratory system. H₂S has been proposed to be an endogenous gasous transmitter similar to two other vasoactive gases, NO (nitric oxide) and CO (carbon monoxide). H₂S was hypothesized to fulfill a physiological role in facilitating the induction of hippocampal long-term potentiation by enhancing the NMDA receptor-mediated responses by induced cyclic AMP. H₂S also affects the vascular and intestinal smooth muscle of mammals and inhibits smooth muscle cell proliferation. The recent study suggested that heart tissues could endogenously produce H₂S as a physiological and pathological cardiac function regulator. It is clear that H₂S relaxed vascular directly through opening ATP-sensitive potassium channels in vascular smooth muscle, different from NO and CO. It is well known that baroreflex is a major way to modulate blood pressure. The effects of H₂S on carotid sinus baroreceptor activity and baroreflex have not been reported yet; the goals of the present research were to observe these effects of H₂S.