Wang Rui
Department of Physiology, University of Saskatchewan, Saskatoon, SK, S7N 5E5 Canada.
Antioxid Redox Signal. 2003 Aug;5(4):493-501. doi: 10.1089/152308603768295249.
A novel concept of "gasotransmitter" arrived recently. Gasotransmitters are small molecules of endogenous gases with important physiological functions. Their production and metabolism are enzymatically regulated, and their effects are not dependent on specific membrane receptors. Following the identification of nitric oxide and carbon monoxide as gasotransmitters, hydrogen sulfide (H(2)S) may be qualified as the third gasotransmitter. Recent studies have shown that H(2)S is generated from vascular smooth muscle cells (SMCs), catalyzed by specific H(2)S-generating enzyme. At physiologically relevant concentrations, H(2)S relaxes vascular tissues, an effect mediated by the activation of ATP-sensitive K(+) (K(ATP)) channels in vascular SMCs. H(2)S directly alters the activity of K(ATP) channels without the involvement of second messengers. Furthermore, the endogenous production of H(2)S in the cardiovascular system is likely regulated by nitric oxide, whereas the vasorelaxant effect of nitric oxide is inhibited by H(2)S. It is anticipated that future studies will better reveal the molecular mechanisms underlying the effect of H(2)S on K(ATP) channel proteins, the interaction of H(2)S and other gasotransmitters in cardiovascular system, the endogenous stimulators and inhibitors of H(2)S metabolism, the role of H(2)S in the regulation of heart function, and the abnormal H(2)S production and action under various pathophysiological conditions.
最近出现了一个关于“气体递质”的新概念。气体递质是具有重要生理功能的内源性气体小分子。它们的产生和代谢受酶调控，其作用不依赖于特定的膜受体。继一氧化氮和一氧化碳被确认为气体递质之后，硫化氢（H₂S）可能成为第三种气体递质。最近的研究表明，H₂S由血管平滑肌细胞（SMC）产生，由特定的H₂S生成酶催化。在生理相关浓度下，H₂S可使血管组织舒张，这一效应由血管SMC中ATP敏感性钾通道（KATP）的激活介导。H₂S直接改变KATP通道的活性，而不涉及第二信使。此外，心血管系统中H₂S的内源性产生可能受一氧化氮调节，而一氧化氮的血管舒张作用则受H₂S抑制。预计未来的研究将更好地揭示H₂S对KATP通道蛋白作用的分子机制、H₂S与心血管系统中其他气体递质的相互作用、H₂S代谢的内源性刺激物和抑制剂、H₂S在心脏功能调节中的作用，以及各种病理生理条件下H₂S产生和作用的异常情况。
