Lipids shed into the culture medium by trypomastigotes of Trypanosoma cruzi

Trypomastigote forms of Trypanosoma cruzi were metabolically, labeled with [C-14]-ethanolamine and [H-3]-palmitic acid. Lipids shed to the culture med ium were analyzed and compared with the parasite components. Phosphatidylch oline and lysophosphatidylcholine accounted for 53% of the total incorporat ed precursor. interestingly, phosphatidylethanolamine and its lyse derivati ve lysophosphatidylethanolamine, although present in significant amounts in the parasites, could not be detected in the shed material. Shed lipids wer e highly enriched in the desaturated fatty acids C-16:1 and C-18:1 when com pared to the total fatty acid pool isolated from the parasites.