title: Temperature and cell-type dependency of sulfide effects on mitochondrial respiration.
abstract: Previous studies suggest that sulfide-induced inhibition of cytochrome c oxidase (cCox) and, consequently, the metabolic and toxic effects of sulfide are less pronounced at low body temperature. Because the temperature-dependent effects of sulfide on the inflammatory response are still a matter of debate, we investigated the impact of varying temperature on the cCox excess capacity and the mitochondrial sulfide oxidation by the sulfide-ubiquinone oxidoreductase in macrophage-derived cell lines (AMJ2-C11 and RAW 264.7). Using an oxygraph chamber, the inhibition of mitochondrial respiration was measured by stepwise titrations with sulfide and the nonmetabolizable cCox inhibitor sodium azide at 25°C and 37°C. Using the latter of the two inhibitors, the excess capacity of the cCox was obtained. Furthermore, we quantified the capacity of these cells to withstand sulfide inhibition by measuring the amount required to inhibit respiration by 50% and 90% and the viability of the cells after 24-h exposure to 100 ppm of hydrogen sulfide. At low titration rates, the AMJ2-C11 cells, but not the RAW 264.7 cells, increased their capacity to withstand exogenously added sulfide. This effect was even greater at 25°C than at 37°C. Furthermore, only the AMJ2-C11 cells remained viable after sulfide exposure for 24 h. In contrast, only in the RAW 264.7 cells that an increase in cCox excess capacity was found at low temperatures. In macrophage-derived cell lines, both the excess capacity of cCox and the efficiency of sulfide elimination may increase at low temperatures. These properties may modify the effects of sulfide in immune cells and, potentially, the inflammatory response during sulfide exposure at different body temperatures.
authors: Sektion Anästhesiologische Pathophysiologie und Verfahrensentwicklung, Klinik für Anästhesiologie, Universitätsklinikum Ulm, Germany.
authors: Michael
authors: M
authors: Groeger
authors: Jose
authors: J
authors: Matallo
authors: Oscar
authors: O
authors: McCook
authors: Florian
authors: F
authors: Wagner
authors: Ulrich
authors: U
authors: Wachter
authors: Olga
authors: O
authors: Bastian
authors: Saskia
authors: S
authors: Gierer
authors: Vera
authors: V
authors: Reich
authors: Bettina
authors: B
authors: Stahl
authors: Markus
authors: M
authors: Huber-Lang
authors: Csaba
authors: C
authors: Szabó
authors: Michael
authors: M
authors: Georgieff
authors: Peter
authors: P
authors: Radermacher
authors: Enrico
authors: E
authors: Calzia
authors: Katja
authors: K
authors: Wagner
mesh_terms: D000818:Animals; D002460:Cell Line; D003576:Electron Transport Complex IV / Q000378:metabolism; D006358:Hot Temperature; D007249:Inflammation / Q000378:metabolism / Q000473:pathology; D016676:Macrophages, Alveolar / Q000166:cytology / Q000378:metabolism*; D017737:Macrophages, Peritoneal / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D008928:Mitochondria / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects*; D013440:Sulfides / Q000494:pharmacology*
chemical_list: D013440:Sulfides; D003576:Electron Transport Complex IV