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Published on: December 18, 2019
Hydrogen sulphide in the hypothalamus causes an ATP-sensitive K+ channel-dependent decrease in blood pressure in
1Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Centre for Life Sciences, 28 Medical Drive, Singapore 117456. gavindawe@nus.edu.sg
Neuroscience
|January 19, 2008
Summary
Hydrogen sulfide (H2S) in the hypothalamus lowers blood pressure and heart rate in rats. This effect is mediated by ATP-sensitive potassium (K(ATP)) channels and can be mimicked by endogenous H2S production.
Area of Science:
- Neuroscience
- Cardiovascular Physiology
- Biochemistry
Background:
- Hydrogen sulfide (H2S) is an endogenous signaling molecule in the brain, primarily produced by cystathionine beta-synthase (CBS).
- H2S influences neuronal activity via N-methyl-D-aspartate (NMDA) receptors and cyclic adenosine 3',5'-monophosphate (cAMP).
- Vasodilatory effects of H2S are linked to ATP-sensitive potassium (K(ATP)) channels in smooth muscle.
Purpose of the Study:
- To investigate the role of H2S in the hypothalamus in regulating blood pressure.
- To determine if H2S acts via K(ATP) channels in the hypothalamus to control blood pressure.
Main Methods:
- Mean arterial blood pressure (MAP) and heart rate were monitored in freely moving rats.
- Drugs were infused into the posterior hypothalamus.
- Effects of H2S donor (NaHS), K(ATP) channel blocker (gliclazide), CBS activator, and CBS inhibitors were assessed.
Main Results:
- Intrahypothalamic infusion of NaHS decreased MAP and heart rate in rats.
- Gliclazide dose-dependently blocked the hypotensive and bradycardic effects of NaHS.
- CBS activation decreased MAP, while CBS inhibition increased MAP.
Conclusions:
- H2S in the hypothalamus reduces blood pressure and heart rate in rats.
- This effect is mediated by K(ATP) channels.
- Endogenous H2S production in the hypothalamus influences blood pressure regulation.
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