Davis W L, Jacoby B H, Jones R G, Goodman D B
Department of Biology, College of Natural and Applied Sciences, Abilene Christian University, TX 79699.
Histochem J. 1993 Jul;25(7):478-90. doi: 10.1007/BF00159283.
In Solenopsis spp., muscle histolysis or breakdown is a normal process in females and is initiated in the flight muscles only immediately after a mating flight. Information regarding the presence of the oxyradical scavenging enzyme superoxide dismutase (SOD) and the formation of the radical oxygen intermediate superoxide (SO) during the early stages of flight muscle histolysis in this insect was investigated. In normal fibrillar flight muscles from control animals, SOD was immunolocalized to vesicular and tubular components of the sarcotubular system. Lanthanum tracer studies indicated that some of these SOD-positive structures might be tubulovesicles continuous with the extracellular space. Following the injection of virgin alates with experimental haemolymph obtained from artificially inseminated females, the membrane delimited elements of the sarcotubular system became increasingly swollen and dilated with time (from 60 to 120 minutes postinjection) with a concomitant decrease in SOD activity and an increase in oxyradical formation. Many similar vesicles were lanthanum-positive. SO was not seen in the sarcoplasmic vesicles and tubules of control insects. The biochemical quantification of SO release over a 2-hour period showed a marked increase in oxyradical formation following treatment with the experimental haemolymph in comparison to control insects. Also, the addition of superoxide dismutase depressed SO formation under these conditions. Despite the histochemical and biochemical changes seen in the muscles of experimental insects, by 2 hours post-treatment there was no evidence of muscle necrosis. From these studies on flight muscle histolysis/necrosis in Solenopsis it appears that the formation of oxyradicals might represent an early event in myopathogenesis and subsequent tissue involution. The generation of SO is more than likely to be associated with alterations in the normal structure, biochemistry and permeability of the biomembranes which delimit the sarcotubular system.
在火蚁属物种中，肌肉组织溶解或分解是雌性的正常过程，且仅在交配飞行后立即在飞行肌肉中开始。研究了关于这种昆虫飞行肌肉组织溶解早期阶段中氧自由基清除酶超氧化物歧化酶（SOD）的存在以及活性氧中间体超氧阴离子（SO）形成的信息。在来自对照动物的正常纤维状飞行肌肉中，SOD免疫定位在肌管系统的囊泡和管状成分上。镧示踪研究表明，这些SOD阳性结构中的一些可能是与细胞外空间连续的微管小泡。在用从人工授精雌性获得的实验性血淋巴注射未交配的有翅蚁后，肌管系统的膜界定元件随时间（注射后60至120分钟）变得越来越肿胀和扩张，同时SOD活性降低，氧自由基形成增加。许多类似的囊泡是镧阳性的。在对照昆虫的肌浆囊泡和小管中未观察到超氧阴离子。与对照昆虫相比，在2小时内对超氧阴离子释放进行的生化定量显示，用实验性血淋巴处理后氧自由基形成显著增加。此外，在这些条件下添加超氧化物歧化酶可抑制超氧阴离子的形成。尽管在实验昆虫的肌肉中观察到了组织化学和生化变化，但在处理后2小时没有肌肉坏死的证据。从这些关于火蚁属飞行肌肉组织溶解/坏死的研究来看，氧自由基的形成可能代表了肌病发病机制和随后组织退化的早期事件。超氧阴离子的产生很可能与界定肌管系统的生物膜的正常结构、生物化学和通透性的改变有关。
