H2S, the potentially novel gasotransmitter during experimental cerebral ischemia

Abstract

Hydrogen sulfide (H2S), a well-known toxic gas, is found in relatively high concentrations in the brain. Although the physiological functions of H2S have been identified in cardiovascular and nervous systems, its role in stroke is not known. We have found that elevated plasma cysteine (the endogenous precursor of H2S) levels are associated with poor clinical outcome in acute stroke patients. Therefore, it is reasonable to hypothesize that H2S plays an important role in mediating cell damage in cerebral ischemia probably through excitotoxicity, as H2S is known to activate NMDA-receptors. Cerebral ischemia was studied in a rat stroke model created by permanent middle cerebral artery occlusion (MCAO). The present results strongly suggest that H2S plays a part in cerebral ischemic damage after stroke. Inhibition of H2S synthesis should be investigated for its potential as a novel neuroprotective stroke therapy.