Seasonality of energetic functioning and production of reactive oxygen species by lugworm (Arenicola marina) mitochondria exposed to acute temperature changes

The influence of seasonal and acute temperature changes on mitochondrial functions were studied in isolated mitochondria of the eurythermal lugworm Arenicola marina (Polychaeta), with special emphasis on the interdependence of membrane potential and radical production. Acclimatisation of lugworms to...

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Bibliographic Details
Published in:	Journal of experimental biology Vol. 207; no. Pt 14; pp. 2529 - 2538
Main Authors:	Keller, Martina, Sommer, Angela Maria, Pörtner, Hans O, Abele, Doris
Format:	Journal Article
Language:	English
Published:	England 15-06-2004
Subjects:	Acclimatization - physiology Analysis of Variance Animals Catalase - metabolism Citrate (si)-Synthase - metabolism Energy Metabolism - physiology Fluorescence Germany Hydrogen Peroxide - metabolism Marine Membrane Potentials - physiology Mitochondria - metabolism Mitochondria - physiology Polychaeta - metabolism Polychaeta - physiology Reactive Oxygen Species - metabolism Seasons Superoxide Dismutase - metabolism Temperature Germany
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Summary:	The influence of seasonal and acute temperature changes on mitochondrial functions were studied in isolated mitochondria of the eurythermal lugworm Arenicola marina (Polychaeta), with special emphasis on the interdependence of membrane potential and radical production. Acclimatisation of lugworms to pre-spawning/summer conditions is associated with rising mitochondrial substrate oxidation rates, higher proton leakage rates, elevated membrane potentials, and increased production of reactive oxygen species (ROS) in isolated mitochondria, compared with mitochondria from winter animals. However, a high ROS production was compensated for by higher activities of the antioxidant enzymes catalase and superoxide dismutase, as well as lower mitochondrial densities in summer compared with winter animals. In summer animals, a higher sensitivity of the proton leakage rate to changes of membrane potential will confer better flexibility for metabolic regulation (mild uncoupling) in response to temperature change. These seasonal alterations in mitochondrial functions suggest modifications of energy metabolism in eurythermal and euryoxic organisms on intertidal mudflats during summer. In winter, low and less changeable temperatures in intertidal sedimentary environments permit higher respiratory efficiency at low aerobic metabolic rates and lower membrane potentials in A. marina mitochondria.
Bibliography:	ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2
ISSN:	0022-0949 1477-9145
DOI:	10.1242/jeb.01050