RATE OF AEROBIC METABOLISM AND SUPEROXIDE PRODUCTION-RATE POTENTIAL IN THE NEMATODE CAENORHABDITIS-ELEGANS

We have monitored oxygen consumption as a measure of the rate of aerob ic metabolism during the lifetime of Caenorhabditis elegans. We have a lso developed a chemiluminescent technique which measures exogenous NA DPH-stimulated superoxide anion production by freeze-thawed worms. In this assay light production depends on the combined activities of all of the enzymes involved in superoxide production, both directly and in directly, thus reflecting their activity levels immediately prior to f reeze fixation. We have designated this parameter the superoxide produ ction rate potential. The superoxide production rate potential is cont rolled by the longevity determining gene age-1 and varies in a life cy cle-dependent fashion. The metabolic rate generally follows these fluc tuations, but additionally shows specific alterations as a response to environmental factors. Metabolic rate and superoxide production rate potential increase by 1.3- and 3-fold, respectively, in reproducing ad ults. This increase is not due to the contribution of embryonating egg s, however. Culture conditions have a large effect on metabolic rate, but not on the superoxide production rate potential. The energetic cos t of movement, measured as consumed oxygen, is low relative to the cos ts of maintenance and reproduction. Identical superoxide production ra te potentials are scored in paralyzed and motile worms, as would be ex pected. (C) 1996 Wiley-Liss, Inc.