Induced hyperlipaemia and immune challenge in locusts

• Published in: Journal of insect physiology 2004-05, Vol.50 (5), p.409-417
• Main Authors: Mullen, Lisa M., Lightfoot, Mary E., Goldsworthy, Graham J.
• Format: Article
• Language: English
• Subjects: adipokinetic hormone; AKH; Animals; antigens; apolipophorin; Apolipoproteins - blood; ApoLp-III; ELISA; enzyme activity; Enzyme-Linked Immunosorbent Assay - methods; Fat body; Fat Body - metabolism; Glucans; Grasshoppers - immunology; Grasshoppers - metabolism; hemolymph; Hemolymph - chemistry; Hemolymph - enzymology; Hemolymph - metabolism; hormone secretion; hyperlipidemia; Hyperlipidemias - chemically induced; Hyperlipidemias - immunology; Hyperlipidemias - metabolism; immune response; immunization; Immunogens; Insect Hormones - blood; Insect Hormones - immunology; Insect Hormones - pharmacology; insect immunity; Laminarin; LDLp; lipemic effect; lipid content; Lipids - blood; lipophorin; lipopolysaccharides; Lipopolysaccharides - pharmacology; Lipoproteins, LDL - blood; Locusta; Locusta migratoria; Locusta migratoria migratorioides; locusts; LPS; Male; monophenol monooxygenase; Monophenol Monooxygenase - metabolism; Oligopeptides - blood; Oligopeptides - immunology; Oligopeptides - pharmacology; Passive immunisation; Phenoloxidase; polysaccharides; Polysaccharides - pharmacology; prophenoloxidase; Pyrrolidonecarboxylic Acid - analogs & derivatives; triacylglycerols; β-1,3-glucan
• ISSN: 0022-1910; 1879-1611
• DOI: 10.1016/j.jinsphys.2004.02.008

Injections of immunogens, such as β-1,3-glucan or lipopolysaccharide (LPS), bring about a marked hyperlipaemia with associated changes in lipophorins and apolipophorin-III in the haemolymph of Locusta migratoria. These changes are similar to those observed after injection of adipokinetic hormone (AKH). The possibility that endogenous AKH is released as part of the response to these immunogens is investigated using passive immunisation against AKH-I, and measurement of AKH-I titre in the haemolymph after injection of immunogens. The data presented show that, despite the similarity of the changes brought about by the presence of immunogens in the haemolymph to those brought about by AKH, there is no release of endogenous AKH after injection of laminarin or LPS. A direct effect of the immunogens on release of neutral lipids by the fat body cannot be demonstrated in vitro, and the mechanism by which hyperlipaemia is induced during immune challenge remains uncertain.