Metabolic pathways for dietary lipids in the midgut of hematophagous Panstrongylus megistus (Hemiptera: Reduviidae)

CANAVOSO LE; FREDE S; RUBIOLO ER

Elsevier - Science Direct

Año: 2004 vol. 34 p. 845 - 845

he metabolism of dietary lipids in the anterior midgut of Panstrongylus megistus during blood digestion was studied. Fifth instar nymphs were fed a blood meal containing 7:1 0:4 mg of lipids, consisting mainly of triacylglycerol (TAG), and completed the overall process of digestion in about 20 days. Lipolysis of TAG and pathways for diacylglycerol (DAG) biosynthesis in the midgut were investigated by feeding the insects with [9,10-3H]-oleic acid-labeled triolein. Lumenal [3H]-triacylglycerol was hydrolyzed, generating mainly fatty acids (FA) and glycerol and to lesser extent, DAG. Almost no radioactivity associated with monoacylglycerol was found at any time. In midgut tissue, labeled fatty acids were incorporated into phosphatidic acid, DAG and TAG, whereas no significantly labeled monoacylglycerol was observed. In addition, the activities of enzymes related to DAG metabolism were assayed in non-blood fed midgut homogenates and at different times after feeding on a blood meal