We investigated aerobic and anaerobic thiotrophic metabolism by the gutless clam Solemya reidi and its intracellular symbiotic bacteria. Mean environmental sulfide concentrations in porewater next to animals varied from a high of 888 μM to a low of 17 μM in different sediment samples, while mean thiosulfate concentrations were very low (1-13 μM). The blood of freshly collected clams contained u...

Polymorphonuclear leukocytes (PMN) isolated from human blood were exposed to various levels of hydrogen sulfide. The effect on respiratory burst, myeloperoxidase activity, and capacity to phagocytose and kill bacteria were studied. A 1-h exposure of the PMN to 1 mM sulfide did not decrease their myeloperoxidase activity or their capacity to initiate a respiratory burst. Actually the products of...

Hydrogen sulfide is gaining acceptance as an endogenously produced modulator of tissue function. The present paradigm of H(2)S (diprotonated, gaseous form of hydrogen sulfide) as a tissue messenger consists of H(2)S being released from the desulfhydration of l-cysteine at a rate sufficient to maintain whole tissue hydrogen sulfide concentrations of 30 microM to >100 microM, and these tissue con...

Chicken liver mitochondria consumed O2 at an accelerated rate when supplied with low concentrations of hydrogen sulfide. Maximum respiration occurred in 10 microM sulfide, and continued more slowly up to concentrations as high as 60 microM. Sulfide oxidation was coupled to adenosine triphosphate (ATP) synthesis, as shown by firefly luciferase luminescence and by measurement of the mitochondrial...

Vesicomyid clams, vestimentiferans, and some bathymodiolin mussels from hydrothermal vents and cold seeps possess thiotrophic endosymbionts, high levels of hypotaurine and, in tissues with symbionts, thiotaurine. The latter, a product of hypotaurine and sulfide, may store and/or transport sulfide non-toxically, and the ratio to hypotaurine plus thiotaurine (Th/[H+Th]) may reflect an animal's su...

Hydrogen sulfide is an essential gasotransmitter associated with numerous pathologies. We assert that hydrogen sulfide plays an important role in regulating macrophage function in response to subsequent inflammatory stimuli, promoting clearance of leukocyte infiltrate and reducing TNF-α levels in vivo following zymosan-challenge. We describe two distinct methods of measuring leukocyte hydrogen ...

Respiration of plume tissue of the hydrothermal vent tube worm Riftia pachyptila is insensitive to sulfide poisoning in contrast to tissues of animals that do not inhabit vents. Permeability barriers may not be responsible for this insensitivity since plume homogenates are also resistant to sulfide poisoning. Cytochrome c oxidase of plume, however, is strongly inhibited by sulfide at concentrat...

In situ grown nickel sulfide and cobalt sulfide hierarchical nanospheres on F-doped SnO2 (FTO) substrates exhibited comparable catalytic activities to sputtering Pt on the counter electrodes for dye-sensitized solar cells (DSSCs). The fresh cells with the nickel sulfide and cobalt sulfide on the counter electrodes could reach power conversion efficiencies of 6.81% and 6.59% respectively, approa...

Sulfide:quinone oxidoreductase (SQR) catalyzes sulfide oxidation during sulfide-dependent chemo- and phototrophic growth in bacteria. The green sulfur bacterium Chlorobaculum tepidum (formerly Chlorobium tepidum) can grow on sulfide as the sole electron donor and sulfur source. C. tepidum contains genes encoding three SQR homologs: CT0117, CT0876, and CT1087. This study examined which, if any, ...