Studies on nitric oxide (NO) and heme oxygenase-1 (HO-1)-mediated production of carbon monoxide (CO) have highlighted the possible crosstalk between gaseous signaling molecules in biology. Further evidence suggested that another novel endogenous gasotransmitter, hydrogen sulfide (H2S), also plays important physiological functions alongside NO and CO in animal systems (Wang, 2003). For example, anti-inflammatory, metabolic, vasorelaxant, neuroprotective and psychological functions of H2S have been described among others (Wang, 2002).