The Cardiovascular Effects of Central Hydrogen Sulfide Are Related to KATP Channels Activation

Abstract

Hydrogen sulfide (H2S), an endogenous “gasotransmitter”, exists in the central nervous system. However, the central cardiovascular effects of endogenous H2S are not fully determined. The present study was designed to investigate the central cardiovascular effects and its possible mechanism in anesthetized rats. Intracerebroventricular (icv) injection of NaHS (0.17~17 μg) produced a significant and dose-dependent decrease in blood pressure (BP) and heart rate (HR) (P<0.05) compared to control. The higher dose of NaHS (17 μg, n=6) decreased BP and HR quickly of rats and 2 of them died of respiratory paralyse. Icv injection of the cystathionine beta-synthetase (CBS) activator s-adenosyl-L-methionine (SAM, 26 μg) also produced a significant hypotension and bradycardia, which were similar to the results of icv injection of NaHS. Furthermore, the hypotension and bradycardia induced by icv NaHS were effectively attenuated by pretreatment with the KATP channel blocker glibenclamide but not with the CBS inhibitor hydroxylamine. The present study suggests that icv injection of NaHS produces hypotension and bradycardia, which is dependent on the KATP channel activation.

Superoxide Mediates Depressive Effects Induced by Hydrogen Sulfide in Rostral Ventrolateral Medulla of Spontaneously Hypertensive Rats

“…Systemic administration of H 2 S donors and precursors decreased mean arterial pressure (MAP) in various models of hypertension [ 10 – 13 ]. Nevertheless, mediation of H 2 S in the cardiovascular center has been controversial [ 14 – 16 ].…”

Evidence of hydrogen sulfide involvement in amyotrophic lateral sclerosis

“…15,16 In different types of cells, including neurons, vascular smooth muscle cells, cardiomyocytes, and pancreatic b-cells, H 2 S stimulates the activity of the adenosine triphosphate-sensitive potassium channels. [17][18][19] In the central nervous system, H 2 S attenuates the neuroinflammatory processes induced by lipopolysaccharide (LPS) 20 and amyloid-b. 21 It suppresses oxidative stress induced by hydrogen peroxide, 22 and protects cells against the neurotoxins rotenone 23 and 6-hydroxydopamine.…”

Gaseous Modulators in the Control of the Hypothalamic Neurohypophyseal System

“…Furthermore, it has been recently demonstrated that the enzyme CBS is expressed in the PVN (101). Accordingly, H 2 S has been shown to participate in the hypothalamic control of heart rate and blood pressure (27,67), body temperature during hypoxia (64), and corticotropin-releasing hormone (CRH) release (29).…”