Premium
Analysis of lipids in the salivary glands of Amblyomma americanum (L.): Detection of a high level of arachidonic acid
Author(s) -
Shipley Michael M.,
Dillwith Jack W.,
Sauer John R.,
Essenberg Richard C.,
Howard Ralph W.
Publication year - 1993
Publication title -
archives of insect biochemistry and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.576
H-Index - 66
eISSN - 1520-6327
pISSN - 0739-4462
DOI - 10.1002/arch.940230106
Subject(s) - arachidonic acid , amblyomma americanum , phospholipase a2 , biology , phospholipid , phosphatidylcholine , biochemistry , phosphatidylethanolamine , fatty acid , polyunsaturated fatty acid , metabolism , phospholipase , ixodidae , enzyme , botany , membrane , larva
Analysis of lipids in salivary glands of the lone star tick, Amblyomma americanum , demonstrated that arachidonic acid (20:4, n‐6) comprises 8% of all fatty acids identified by gas chromatography. The occurrence of arachidonic acid and other C 20 polyunsaturated fatty acids in tick salivary glands was confirmed by gas chromatography‐mass spectrometry. Arachidonate is located entirely in the phospholipid fraction and is associated exclusively with phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Salivary glands stored and frozen for several months had a similar lipid composition as freshly dissected salivary glands, with the exception of a small amount of free arachidonic acid and an increase in lysophosphatidylcholine. Incubation of salivary gland homogenates with snake venom phospholipase A 2 showed that most saturated fatty acids are esterified in the sn‐1 position of PC and PE, with the unsaturated fatty acids in the sn‐2 position. Approximately 75% of arachidonic acid is in the sn‐2 position of PC and PE, adding support to the hypothesis that arachidonic acid is released into the cytoplasm after activation of a phospholipase A 2 for subsequent metabolism to prostaglandins and/or other eicosanoids. © 1993 Wiley‐Liss, Inc.