title: Effect of temperature on fatty acid composition in each lipid fraction of Spirometra erinaceieuropaei plerocercoids.
abstract: The effects of temperature and host fatty acids on the fatty acid contents of Spirometra erinaceieuropaei plerocercoids were investigated to clarify their role in sparganosis. After 24 hr incubation at 18 C in host snake serum, omega6 series fatty acids, especially arachidonic acid in the phospholipid fraction of the plerocercoids, increased compared with those of plerocercoids incubated at 37 C. The changes in the ratio of polyunsaturated to saturated fatty acids in the phospholipid fraction of plerocercoids incubated in physiological saline for 6 hr at 10 C were almost the same as the changes at 37 C. The ratio of polyunsaturated to saturated fatty acids of the triglyceride fraction showed almost opposite change versus the phospholipid fraction. The percentage of arachidonic acid in the phospholipid fraction of plerocercoids increased during the first 3 hr of incubation and then decreased, regardless of temperature. At 37 C, the percentage of arachidonic acid in the free fatty acid fraction fell for the first 3 hr of incubation and was significantly elevated at the end of the 6-hr incubation. At 10 C, however, arachidonic acid in the free fatty acid fraction decreased for the first hour of incubation, increased at 3 hr of incubation, then decreased again. These results suggest that fatty acids of the plerocercoids are frequently exchanged between fractions. Plerocercoids can mobilize arachidonic acid to the free fatty acid fraction more quickly at lower temperature than at higher temperature. They may utilize mobilized arachidonic acid early in the infection stage to produce prostaglandins. Alternatively, they can incorporate arachidonic acid into the phospholipid fraction again when arachidonic acid is readily available in the environment.
authors.affiliation: Department of Environmental Medicine, Shimane Medical University, Izumo City, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Fukushima
authors.forename: T
authors.initials: T
authors.lastname: Gao
authors.forename: A
authors.initials: A
authors.lastname: Isobe
authors.forename: N
authors.initials: N
authors.lastname: Hojo
authors.forename: K
authors.initials: K
authors.lastname: Shiwaku
authors.forename: Y
authors.initials: Y
authors.lastname: Yamane
mesh_terms: D000818:Animals; D016718:Arachidonic Acid / Q000032:analysis; D017815:Elapidae; D005227:Fatty Acids / Q000032:analysis*; D015525:Fatty Acids, Omega-3 / Q000032:analysis; D013146:Spirometra / Q000737:chemistry*; D013696:Temperature
chemical_list: D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D016718:Arachidonic Acid