• Treatment with NaHS or 1400W significantly attenuated the airways eosinophilia that was paralleled by an increase in aconitase activity and decrease of lipid peroxidation. Increased GSH/GSSG ratio caused by either H₂S supplementation or iNOS-inhibition is a potential mechanism protecting airways against oxidative stress and inflammatory lung diseases.1
  • A 50% reduction in the total number of alveoli was observed with reduced H₂S forming enzymes CBS and CSE and demonstrated a 100-500% increase in the muscularization of small- and medium-sized lung vessels, which was accompanied by increased vessel wall thickness, and an apparent decrease in lung vascular supply. Exogenous administration of H₂S promoted endothelial tube formation in mice. These data confirm a key role for the H₂S -generating enzymes Cbs and Cth in pulmonary vascular development and homeostasis and in lung alveolarization.2
  • In the eosinophilic group, lower exhaled H₂S were found and exhaled H2 S levels were negatively correlated with sputum eosinophil counts (R = -0.428, P < 0.01). Exhaled H2 S levels were positively correlated with percent of predicted forced expiratory volume in 1 s (R = 0.567, P < 0.01) and ACT score (R = 0.519, P < 0.01).3
  • Findings demonstrate that H₂S causes the relaxation of human ASM and implicate as well the role for sarcolemmal KATP channels. Finally, given that ASM cells express intrinsic enzymatic machinery of generating H₂S , we suggest thereby this class of gasotransmitter can be further exploited for potential therapy against obstructive lung disease. 4
  • H₂S causes airway SMC relaxation by inhibiting Ca(2+) release through InsP3Rs and consequent reduction of agonist-induced Ca(2+) oscillations in SMCs. The results suggest a novel role for endogenously produced H₂S that involves the modulation of InsP3-evoked Ca(2+) release – a cell-signalling system of critical importance for many physiological and pathophysiological processes.5
  • Compared to healthy children, both serum H₂S concentration and all lung function parameters were significantly decreased in children with asthma (P<0.05). Furthermore, serum H₂S concentration was positively correlated with lung function indices (P<0.05). Thus, decreasing levels of H₂S in the serum may be used to indicate decreasing lung function.6)
  • In patients with asthma, serum H₂S levels are significantly reduced and abnormal metabolism and function of H₂S have been reported in experimental animals with asthma. Supplementation with exogenous H₂S has been shown to mitigate the severity of asthma in experimental animals. It is hypothesized that decreased H₂S production in the lung and airway tissues may be used as an early detection biomarker, and H₂S -based therapy would represent a new treatment strategy for asthma.7