Adipokinetic hormone induces changes in the fat body lipid composition of the beetle Zophobas atratus.

In insects, neuropeptide adipokinetic hormone (AKH) released from the corpora cardiaca mobilizes lipids and carbohydrates in the fat body. We examined the developmental differences in the action of Tenmo-AKH, a bioanalogue belonging to the adipokinetic/hypertrahelosemic family (AKH/HrTH), on the lipid composition of larval and pupal fat bodies in the beetle Zophobas atratus. Tenmo-AKH was administered to the beetle larvae and pupae either as a single dose or as two doses of 20 pmol during a 24h interval. Extracts of fat bodies were used to analyse the lipid composition by gas chromatography (GC) combined with mass spectrometry (GC-MS). Control extracts were analyzed using the same method. Fatty acids (FA) and fatty acid methyl esters (FAME) were the most abundant compounds in the fat bodies from both developmental stages. We observed significant differences in their concentrations following hormonal treatment. Tenmo-AKH also induced a distinct increase in larval sterols, fatty alcohols and benzoic acid.