Fatty acid composition of phospholipids and metabolism in rectal tissues of the African locust

Abstract Six groups of phospholipids were separated from the rectal tissues of the African locust: phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositols, phosphatidylserine, sphingomyelin and cardiolipins. Saturated and unsaturated C18 components were abundant, as is generally observed in insects. Odd-chain (15:0,17:0, 17:1) and long-chain fatty acids were also detected. Both [ 14 c]18:2n-6 and [ 14 c]20:4n-6 were metabolized into prostaglandins (primarily PGE 2 ) and HODEs, respectively, by the intervention of PGH-synthases. Incorporation of [ 14 c]18:2n-6 into phospholipids and neutral lipids or active exchanges of the fatty acid between both categories of lipids reflected different phospholipase, lipase and transferase activities. Triglycerides appeared as a major source of fatty acids for locust rectum phospholipids. These data emphasize a major role of polyunsaturated fatty acids in insect renal physiology.