[Advances in study of physiologic effects of endogenous sulfur dioxide and its derivatives]

Sulfur dioxide (SO2) is an ordinary air pollutant globally and harm to human health. L-cysteine is the major sulfur-containing amino acid and its normal metabolism can produce hydrogen sulfur (H2S) and SO2. It is realized that H2S has various bioactivities and is the third gasotransmitter after nitric oxide (NO) and carbon monoxide (CO). Recently, attention has been paid to the physiologic effects of endogenous SO2 and its derivatives (bisulfite and sulfite) in vivo, and recognized that SO2 and its derivatives can lower blood pressure, change heart rates, participate in inflammatory reactions, and so on, suggesting that endogenous SO2 may modulate the physiologic functions in vivo as a bioactive molecule.