The history of gases acting as mediator starts with the discovery that NO accounted for endothelial derived relaxing factor (EDRF) activity. Since then the involvement of NO in physiological and pathological processes has been well defined and characterized both at biological and molecular levels. The most important issue, in our view, is that all these studies lead to the concept that i) a gas can act as transmitter / mediator in the human body ii) a gas can stimulate an enzymatic activity. Hydrogen sulphide has been identified as mediator by Abe & Kimura in 1996. Since then there has been an increasing interest on this gas. NO is generated by nitric oxide synthase NOS, namely iNOS, eNOS and nNOS, starting from L-arginine. Similarly Hydrogen sulphide is generated starting from L-cysteine by three different enzymes namely cysthathionine- β-synthase (CBS), cystathionine- γ-lyase (CSE) and 3-Mercaptopyruvate sulfurtransferase (3-MST). As NO studies performed in the past 5 years have shown that this pathways is involved in cardiovascular physiology and pathology. Papers published on hydrogen sulphide from about 100 in 2008 are now more than quadruplicated. It is intuitive that these two pathways, that contributes to the homeostasis of the cardiovascular system, may cross-talk between them. At the present there are very few studies addressing a possible correlation between the L-Cysteine/ H2S and the L-arginine/NO pathway. The aim of the meeting is to put together experts in the field of Nitric Oxide and Hydrogen sulphide in order to discuss on the novel findings that have been achieved recently. Particular attention will be given at their role in cardiovascular diseases and the possible interaction between the two pathway will be discussed.
Chair of the Meeting Giuseppe Cirino