Mochanová Michaela, Tomčala Aleš, Svobodová Zdeňka, Kodrík Dalibor
Institute of Entomology, Biology Centre, CAS, Branišovská 31, 370 05 České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic.
Institute of Parasitology, Biology Centre, CAS, Branišovská 31, 370 05 České Budějovice, Czech Republic.
Comp Biochem Physiol B Biochem Mol Biol. 2018 Dec;226:26-35. doi: 10.1016/j.cbpb.2018.08.004. Epub 2018 Aug 12.
The role of adipokinetic hormone (Drome-AKH) in maintaining the levels of basic nutrients, under starvation conditions, was studied using Drosophila melanogaster mutants with AKH deficiency (Akh) and AKH abundance (EE-Akh). Our results showed lipids as the main energy reserve in Drosophila, and their physiological level and metabolism were shown to be under the control of AKH. AKH abundance in the body resulted in lower levels of triacylglycerols and diacylglycerols than in the controls, probably due to a more intensive metabolism; interestingly, there was a disproportional representation of fatty acids in triacylglycerols and diacylglycerols in Drosophila. Lower level of glycogen and its partial control by AKH suggest its lesser role as the storage substance. However, maintenance of free carbohydrate level in Drosophila seemed to be critical; when glycogen stores are exhausted, carbohydrates are synthesized from other sources. Protein levels and their alterations, under starvation, did not seem controlled by AKH. AKH-deficient flies were more resistant while AKH-abundant flies were more sensitive to starvation; females were found to be more resistant than males, regardless of the AKH level, probably due to higher body mass and higher amount of nutrients. However, in accordance with the level of all nutrients, that of AKH also gradually decreased with prolonged starvation.
利用缺乏脂肪动激素（Drome - AKH）的果蝇突变体（Akh）和脂肪动激素过量的果蝇突变体（EE - Akh），研究了脂肪动激素（Drome - AKH）在饥饿条件下维持基本营养物质水平的作用。我们的研究结果表明，脂质是果蝇的主要能量储备，其生理水平和代谢受脂肪动激素的控制。果蝇体内脂肪动激素过量导致三酰甘油和二酰甘油水平低于对照组，这可能是由于代谢更活跃；有趣的是，果蝇的三酰甘油和二酰甘油中脂肪酸的比例不均衡。糖原水平较低且受脂肪动激素部分控制，这表明糖原作为储存物质的作用较小。然而，维持果蝇体内游离碳水化合物水平似乎至关重要；当糖原储备耗尽时，碳水化合物会从其他来源合成。饥饿时蛋白质水平及其变化似乎不受脂肪动激素控制。缺乏脂肪动激素的果蝇更具抗性，而脂肪动激素过量的果蝇对饥饿更敏感；无论脂肪动激素水平如何，雌性果蝇比雄性果蝇更具抗性，这可能是由于雌性体重更高且营养物质含量更多。然而，与所有营养物质的水平一致，随着饥饿时间延长，脂肪动激素的水平也逐渐降低。
