Estimation of hydrogen sulphide in the human lymphocytes

Abstract

179-182Hydrogen sulphide (H₂S), a signaling gasotransmitter and a potent vasorelaxant is endogenously produced by the enzymes cystathionine-β-synthase (CBS) and cystathionine-ϒ-lyase (CSE). CBS is a predominant source of H₂S in the central nervous system, while CSE is the major H₂S producing enzyme in the brain and other nervous tissues. Though the expression of these enzymes in the blood lymphocytes is known, H₂S formation in the lymphocytes has not been reported so far. In the present study, H₂S levels in the lymphocytes of healthy control subjects were estimated, after suitable modifications in a routine method [Stipanuk M H & Beck P W (1982) Biochem J 206, 267-277] used for detecting tissue levels of H₂S. In this method, homocysteine (Hcys) due to its higher solubility was used as the substrate in place of L-cysteine and NaOH was used in place of zinc acetate to increase the entrapment of H₂S in the central well. A mean H₂S level of 11.64 ± 6.36 µM/min/mg protein was detected in the lymphocytes of 8 subjects (mean age, 24 ± 2; 2 male, 6 female). The modified method was found to be more sensitive for H₂S estimation in human lymphocytes. As endogenous H₂S is reported to be involved in the pathogenesis of various cardiovascular and pulmonary diseases, the levels of H₂S in lymphocytes can be a marker of the endogenous tissue levels