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Metabolism of long‐chain fatty acids, alcohols and alkylglycerols in the fish parasite Paratenuisentis ambiguus (Acanthocephala)
Author(s) -
Filipponi Christin,
Taraschewski Horst,
Weber Nikolaus
Publication year - 1994
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/bf02536631
Subject(s) - acanthocephala , chemistry , metabolism , fish <actinopterygii> , biochemistry , biology , zoology , fishery , helminths
Abstract Specific differences between the acyl composition of lipids on the helminth Paratenuisentis ambiguus and its host eel, as shown previously, prompted us to study the lipid metabolism in this intestinal fish parasite. Adults and larvae of P. ambiguus were fed various lipid precursors, e.g., fatty acids, long‐chain alcohols and 1‐ O ‐alkylglycerols, which may occur as common nutrients of intestinal parasites. Incorporation of [1‐ 14 C]palmitic acid into neutral and polar lipids was found to be similar under aerobic and near‐anaerobic conditions. In adult parasites maintained in culture medium supplemented with glucose, [1‐ 14 C]palmitic acid was incorporated mainly into triacylglycerols and phosphatidylcholines, whereas [1‐ 14 C]oleic acid was incorporated preferentially into triacylglycerols. In fasted adults, as well as in larvae, [1‐ 14 C]oleic acid was mainly transferred to phosphatidylcholines. Lipolytic activity was detected in adult parasites that had been incubated with radioactive trioleoylglycerol. [1‐ 14 C]Hexadecan‐1‐ol was oxidized in P. ambiguus at a high rate to labeled palmitic acid, which was incorporated into various lipid classes of P. ambiguus . Small but significant proportions of radioactivity from hexadecan‐1‐ol were incorporated into ether glycerolipids of the parasite. A more direct precursor in ether glycerolipid metabolism, i.e., rac ‐1‐ O ‐[1′‐ 14 C] hexadecylglycerol, was incorporated into alkyl and 1′‐alkenyl moieties of choline and etha‐nolamine etherglycerophospholipids of P. ambiguus in high yield. High proportions of labeled diacylglycerols, triacylglycerols and steryl esters were detected in surface lipids as well as lipid extracts of the culture media after incubation of P. ambiguus with [1‐ 14 C]palmitic or [1‐ 14 C]oleic acids. The results suggest that palmitic acid and oleic acid are incorporated into neutral and polar lipids of P. ambiguus maintained in glucose medium quite differently with oleic acid showing a strong preference for triacylglycerols. However, the incorporation of palmitic acid in glucose‐fed parasites was similar to that of oleic acid in fasted parasites, as well as in larvae. This may be explained by partial fatty acid depletion in fasted worms and rapid cell division in larvae, respectively.