PYRUVATE METABOLISM IN LABORATORY-ACCLIMATED AND FRESHLY COLLECTED SEA-ANEMONES, METRIDIUM-SENILE L

Utilization of pyruvate as a precursor for glycogen, lipid, and protei n biosynthesis was investigated in freshly collected and laboratory-ac climated individuals of the sea anemone Metridium senile (L.). Pyruvat e uptake rates, oxidation of pyruvate to CO2 and glycolytic flux, meas ured by in vitro radiotracer methods, were higher in freshly collected anemones than in laboratory-acclimated anemones. Incorporation of [C- 14]pyruvate carbon into the lipid fraction of anemone tissues was low. Incorporation of pyruvate carbon into anemone protein varied with pyr uvate uptake rate, and was therefore higher in field anemones. Pyruvat e oxidation to CO2, expressed as a fraction of pyruvate uptake, was lo wer in laboratory-acclimated anemones than in freshly collected ones, and the difference is reflected in relatively higher amounts of pyruva te incorporated into the glycogen fraction of laboratory-acclimated an emones. These differences in pyruvate metabolism may be the result of lower food availability under laboratory conditions and/or differences between the biochemical compositions of natural prey and Artemia naup lii provided in the laboratory.