Reappraisal of H2S/sulfide concentration in vertebrate blood and its potential significance in ischemic preconditioning and vascular signaling

• DOI: 10.1152/ajpregu.00025.2008
• Publication Date: 2008-04-17T01:38:15Z
• Authors: Nathan L. Whitfield; Edward L. Kreimier; Francys C. Verdial; Nini Skovgaard; Kenneth R. Olson
• Keywords: Hypoxia; Venous blood

Hydrogen sulfide (H(2)S) is rapidly emerging as a biologically significant signaling molecule. Studies published before 2000 report low or undetectable H(2)S (usually total sulfide) levels in blood plasma, whereas recent work has reported concentrations between 10 and 300 microM, suggesting it acts circulating signal. In the first series of experiments, we used recently developed polarographic sensor to measure baseline level endogenous gas turnover exogenous real time from numerous animals, including lamprey, trout, mouse, rat, pig, cow. We found that, contrary reports, was essentially (<100 nM all animals. Furthermore, removed blood, 5% bovine serum albumin vitro intact trout vivo. To determine if could transiently increase, measured oxygen-dependent production by hearts been shown mediate ischemic preconditioning (IPC) mammals. IPC present and, unlike mammals, myocardium obtains its oxygen relatively hypoxic systemic venous blood. vitro, myocardial inversely related Po(2), failed detect ventral aortic either normoxic fish These results provide an autocrine paracrine mechanism for coupling hypoxia IPC, i.e., sensing, but they fail any evidence that mediated circulation.