The use of decapitated insects to study lipid mobilization in adult Manduca sexta: Effects of adipokinetic hormone and trehalose on fat body lipase activity
The use of decapitated insects to study lipid mobilization in adult Manduca sexta: Effects of adipokinetic hormone and trehalose on fat body lipase activity
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DOI：
10.1016/s0965-1748(96)00024-0
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发表时间：
1996-09-01
影响因子：
3.8
通讯作者：
Wells, MA
中科院分区：
文献类型：
--
作者：
Arrese, EL;RojasRivas, BI;Wells, MA
为了研究成体M.第六，有必要克服饥饿和处理的影响，这两者都引起血淋巴脂质浓度的增加。当将海藻糖注射到完整的昆虫中时，在30 min内观察到富含二酰基甘油（DG）的血淋巴脂蛋白、低密度脂蛋白（LDLp）的含量降低35%，但LDLp的水平在1 h后恢复到对照值，断头的昆虫表现出LDLp浓度降低60%，并且水平保持低水平至少24小时。与完整的昆虫相反，向断头的动物中注射海藻糖不会改变LDLp浓度。断头后，对脂肪运动激素（AKH）的反应和脂肪体将DG释放到血淋巴中的能力维持至少24小时。在断头的昆虫中，6 pmol的AKH刺激的可测量的脂质动员，并且用100 pmol的激素获得接近最大的响应。研究了海藻糖和AKH对断头动物中脂肪体三酰甘油（TG）-脂肪酶活性的作用，海藻糖处理的昆虫脂肪体匀浆显示TG-脂肪酶活性比对照昆虫低40%，注射AKH后观察到脂肪体甘油三酯-脂肪酶的活化，AKH注射后10分钟，激活程度在97 - 380%之间。时间过程研究表明，脂肪体三酰甘油脂肪酶的激活先于血淋巴LDL β浓度的增加，表明脂肪酶的激活启动脂质动员。因此，用去头昆虫注射海藻糖是一个非常有用的系统，用于研究激素对成虫脂质动员的调节。六。版权所有（C）1996 Elsevier Science Ltd
In order to perform studies on lipid mobilization in adult M. sexta, it is necessary to overcome the effects of starvation and handling, which both provoke an increase in hemolymph lipid concentration, When trehalose was injected into intact insects, a 35% decrease in the content of the diacylglycerol (DG)-rich hemolymph lipoprotein, low density lipophorin (LDLp) was observed within 30 min, but the level of LDLp returned to control values after 1 h, Decapitated insects exhibited 60% reduction in LDLp concentration and the levels remained low for at least 24 h, In contrast to intact insects, injection of trehalose into decapitated animals did not alter the LDLp concentration, After decapitation, the response to adipokinetic hormone (AKH) and the ability of the fat body to release DG into the hemolymph was maintained for at least 24 h, In decapitated insects, 6 pmol of AKH-stimulated measurable lipid mobilization and a near maximum response was obtained with 100 pmol of the hormone, The action of trehalose and AKH on the fat body triacylglycerol (TG)-lipase activity in decapitated animals was studied, Fat body homogenates from trehalose-treated insects exhibited a TG-lipase activity 40% lower than the control insects, Activation of fat body triacylglycerol-lipase was observed after injection of AKH, with the extent of activation ranging between 97 and 380% ten min after AKH injection, A time course study showed that the activation of the fat body triacylglycerol lipase preceded the increase in hemolymph LDLp concentration, suggesting that activation of the Lipase initiates lipid mobilization. It is concluded that decapitated insects injected with trehalose is a very useful system for investigating the hormonal regulation of lipid mobilization in adult M. sexta. Copyright (C) 1996 Elsevier Science Ltd