Detection of hydrogen sulfide in biological samples: current and future

Evaluation of: Levitt MD, Abdel-Rehim MS, Furne J. Free and acid-labile hydrogen sulfide concentrations in mouse tissues: anomalously high free hydrogen sulfide in aortic tissue. Antioxid. Redox Signal. DOI: 10.1089/ars.2010.3525 (2010) (Epub ahead of print). Hydrogen sulfide (H(2)S), known as a pungent toxic gas, has recently emerged as a novel critical mediator in the cardiovascular system, the nervous system and various biological signaling functions, as well as a therapeutic agent. However, much less certainty exists regarding biological levels of H(2)S in these systems and during disease. Many papers have reported various methods of measuring the levels of sulfide through different techniques both in vitro and in vivo. Complicating this matter is the fact that sulfide exists in multiple forms - free sulfides such as S(2) (-), HS(-), H(2)S, acid-labile and bound sulfides. These different forms of sulfide make quantitative measurement of bioavailable H(2)S difficult and have led to variable reported levels in the literature. The sensitive detection of sulfide in its multiple forms is needed to establish reliable bioavailable concentrations of sulfide species in order to understand their role in various aspects of physiology and pathology, and to address possible therapeutic approaches. A recent method by Levitt et al. describes a unique gas chromatography chemiluminescence-based technique to measure free and acid-labile H(2)S in multiple tissues from mouse.