title: The effect of adipokinetic hormone on midgut characteristics in Pyrrhocoris apterus L. (Heteroptera).
abstract: Digestive processes and the effect of adipokinetic hormone (Pyrap-AKH) on the amount of nutrients (lipids, proteins, and carbohydrates), and on the activity of digestive enzymes (lipases, peptidases, and carbohydrases) were studied in the midgut of the firebug, Pyrrhocoris apterus. The analyses were performed on samples of anterior (AM), middle (MM) and posterior (PM) midgut parts. The results revealed that the digestion of lipids, carbohydrates and proteins take place in the acidic milieu. The Pyrap-AKH treatment increased significantly the level of lipids and proteins in the midgut, and also the level of triacylglycerols (TGs) predominantly in the AM, and the level of diacylglycerols (DGs) in the MM. The increase was not uniform for all present TG and DG species - those containing the linoleic fatty acid were predominant. No hormonal effect on lipase activity was recorded, while peptidase and glucosidase activity was increased in the MM and PM. All these facts indicate that the Pyrap-AKH probably stimulates digestion by more intensive food ingestion or turnover, and perhaps by the stimulation of metabolite absorption; the activation of digestive enzymes seems to be secondary or controlled by other mechanisms.
authors: Institute of Entomology, Biology Centre, Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic. kodrik@entu.cas.cz
authors: Dalibor
authors: D
authors: Kodrík
authors: Konstantin
authors: K
authors: Vinokurov
authors: Aleš
authors: A
authors: Tomčala
authors: Radomír
authors: R
authors: Socha
mesh_terms: D000681:Amylases / Q000378:metabolism; D000818:Animals; D050260:Carbohydrate Metabolism; D004044:Dietary Proteins / Q000378:metabolism; D004063:Digestion; D005247:Feeding Behavior; D005260:Female; D041981:Gastrointestinal Tract / Q000201:enzymology*; D020062:Heteroptera / Q000378:metabolism*; D007301:Insect Hormones / Q000378:metabolism*; D008049:Lipase / Q000378:metabolism; D050356:Lipid Metabolism; D009842:Oligopeptides / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000378:metabolism; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives* / Q000378:metabolism
chemical_list: D004044:Dietary Proteins; D007301:Insect Hormones; D009842:Oligopeptides; C044833:adipokinetic hormone; D008049:Lipase; D000681:Amylases; D010447:Peptide Hydrolases; D011761:Pyrrolidonecarboxylic Acid