This project has two objectives: (1) To explore the metabolic capabilities of invertebrate species, with emphasis on the ability to metabolize common environmental pollutants. Initially we are studying compounds whose metabolism is well understood in mammals, in order to make comparisons. (2) To investigate the possibility that some types of metabolism studies, especially those which must be preformed in vivo,can be effectively accomplished in species having less developed nervous systems (and are thus presumably less subject to pain and distress) than the more commonly used rodent species. We are presently studying Lumbricus terrestris, the common earthworm (""""""""night crawler') because it has been relatively neglected in studies of metabolic capabilities, and because it is typically exposed to environmental pollutants in landfills. We have observed that while L. terrestris appears to metabolize p,p-DDT, adipate diester, and polychlorinated biphenyls in a manner qualitatively similar to higher animals, the metabolism of phthalate diesters and of phthalic acid itself by earthworms differs considerably from the pattern seen in both higher and lower species. In particular, L. terrestris seems to lack the ability to oxidize the ester side chain of ethylhexyl phthalate, and has the ability (unique among animals tested) to oxidize free phthalic acid completely to carbon dioxide. The latter pathway is currently under investigation. We have also characterized the lipids of L.terrestris, and found them to be extremely complex. The fatty acid compositions of lipid classes differ considerably from what has been reported for this species, due to the increased resolving power of modern capillary column chromatography. Earthworms contain a complex mixture of neutral sterols, which has been resolved and fully characterized for the first time. Glycolipids are major components of the extractable lipids, and have never previously been characterized.
