Lee 1996 Biol Bull

Lee RW, Kraus DW, Doeller JE (1996) Sulfide-stimulation of oxygen consumption rate and cytochrome reduction in gills of the estuarine mussel Geukensia demissa. Biol Bull 191:421-30.

» Biol. Bull. 191: 421-430.

Lee RW, Kraus DW, Doeller JE (1996) Biol Bull

Abstract: Organisms, such as the mussel Geukensia demissa, that inhabit high-sulfide sediments have mechanisms that impede sulfide poisoning of aerobic respiration. Oxygen consumption rates (nO₂) of excised ciliated gills from freshly collected G. demissa were stimulated 3-fold at sulfide concentrations between 200 and 500 {mu}M and remained stimulated at 1000 {mu}M. Maintenance of mussels in sulfide-free conditions resulted in less stimulation of gill nO₂ at <500 {mu}M sulfide and inhibition between 500 and 1000 {mu}M sulfide. Gills of Mytilus galloprovincialis from a sulfide-free environment were inhibited by {ge}200 {mu}M sulfide. These results indicate that sulfide stimulation of nO2 may be correlated to environmental exposure to sulfide. Serotonin, a neurohormonal stimulant of ciliary beating, further increased sulfide-stimulated nO₂, possibly in support of energy demand. Sulfide-stimulated nO₂ was negligible in boiled gills and was 61% inhibited by cyanide, implicating the participation of mitochondrial electron flux. Mitochondrial cytochromes c and oxidase oxidation/ reduction state changed little at <500 {mu}M sulfide, but reduction occurred at 500-2000 {mu}M sulfide, suggesting that although cytochrome oxidation/reduction state may be regulated in the face of increased electron flux, regulation may fail at inhibitory sulfide levels. Sulfide-stimulated nO₂ may represent a detoxification mechanism in G. demissa.

• O2k-Network Lab: US AL Birmingham Kraus DW

Labels: MiParea: Respiration, Comparative MiP;environmental MiP 

Organism: Molluscs  Tissue;cell: Lung;gill 

Enzyme: Complex IV;cytochrome c oxidase  Regulation: Redox state  Coupling state: OXPHOS 

HRR: Oxygraph-2k