Njie-Mbye Ya F, Opere Catherine A, Chitnis Madhura, Ohia Sunny E
Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Texas Southern University Houston, TX, USA.
Front Physiol. 2012 Jul 25;3:295. doi: 10.3389/fphys.2012.00295. eCollection 2012.
Hydrogen sulfide (H(2)S), a colorless gas with a characteristic smell of rotten eggs, has been portrayed for decades as a toxic environmental pollutant. Since evidence of its basal production in mammalian tissues a decade ago, H(2)S has attracted substantial interest as a potential inorganic gaseous mediator with biological importance in cellular functions. Current research suggests that, next to its counterparts nitric oxide and carbon monoxide, H(2)S is an important multifunctional signaling molecule with pivotal regulatory roles in various physiological and pathophysiological processes as diverse as learning and memory, modulation of synaptic activities, cell survival, inflammation, and maintenance of vascular tone in the central nervous and cardiovascular systems. In contrast, there are few reports of a regulatory role of H(2)S in the eye. Accumulating reports on the pharmacological role of H(2)S in ocular tissues indicate the existence of a functional trans-sulfuration pathway and a potential physiological role for H(2)S as a gaseous neuromodulator in the eye. Thus, understanding the role of H(2)S in vision-related processes is imperative to our expanding knowledge of this molecule as a gaseous mediator in ocular tissues. This review aims to provide a comprehensive and current understanding of the potential role of H(2)S as a signaling molecule in the eye. This objective is achieved by discussing the involvement of H(2)S in the regulation of (1) ion channels such as calcium (L-type, T-type, and intracellular stores), potassium (K(ATP) and small conductance channels) and chloride channels, (2) glutamate transporters such as EAAT1/GLAST and the L-cystine/glutamate antiporter. The role of H(2)S as an important mediator in cellular functions and physiological processes that are triggered by its interaction with ion channels/transporters in the eye will also be discussed.
硫化氢（H₂S）是一种无色气体，具有臭鸡蛋的独特气味，几十年来一直被视为一种有毒的环境污染物。自十年前有证据表明其在哺乳动物组织中基础生成以来，硫化氢作为一种在细胞功能中具有生物学重要性的潜在无机气体介质，已引起了广泛关注。当前研究表明，除了其同类物一氧化氮和一氧化碳外，硫化氢是一种重要的多功能信号分子，在各种生理和病理生理过程中发挥关键调节作用，这些过程包括学习与记忆、突触活动调节、细胞存活、炎症以及中枢神经和心血管系统中血管张力的维持等。相比之下，关于硫化氢在眼部调节作用的报道较少。越来越多关于硫化氢在眼组织中药理作用的报道表明，存在一条功能性的转硫途径，并且硫化氢作为一种气体神经调节剂在眼中具有潜在的生理作用。因此，了解硫化氢在与视觉相关过程中的作用，对于我们不断扩展对这种分子作为眼组织中气体介质的认识至关重要。本综述旨在全面且及时地阐述硫化氢作为信号分子在眼中的潜在作用。这一目标通过讨论硫化氢在以下方面的调节作用来实现：（1）离子通道，如钙通道（L型、T型和细胞内储存型）、钾通道（ATP敏感性钾通道和小电导通道）和氯通道；（2）谷氨酸转运体，如兴奋性氨基酸转运体1/谷氨酸天冬氨酸转运体（EAAT1/GLAST）和L-胱氨酸/谷氨酸反向转运体。还将讨论硫化氢作为重要介质在由其与眼内离子通道/转运体相互作用引发的细胞功能和生理过程中的作用。
