Krishnan Natraj, Vecera Josef, Kodrík Dalibor, Sehnal Frantisek
Department of Physiology, Institute of Entomology, Biology Centre, Czech Academy of Sciences, Ceské Budejovice, Czech Republic.
Arch Insect Biochem Physiol. 2007 Jul;65(3):114-24. doi: 10.1002/arch.20182.
Injections of 38 pmol paraquat (1,1'-dimethyl-4,4'-bypyridilium) into adult Pyrrhocoris apterus (average body weight 29.6 mg in males and 36.9 mg in females) caused a significant elevation of lipid peroxidation and protein carbonylation and a decline of membrane fluidity in the microsomal brain fraction. Another manifestation of oxidative stress was a depletion of the reduced glutathione pool and reduction of the gamma-glutamyl transpeptidase activity in the brain extracts. The damaging action of paraquat on the brain was counteracted by simultaneous injection of 1 pmol 20-hydroxyecdysone (20E). 20E restrained lipid peroxidation and the formation of protein carbonyls, ameliorated changes in microsomal membrane fluidity, enhanced the level of reduced glutathione, and upregulated the activity of gamma-glutamyl transpeptidase. At the organismic level, 20E curtailed three detrimental effects caused by paraquat injection: the disappearance of a blood protein, the suppression of fecundity and egg hatchability, and the shortening of adult life span. The data showed that 20E provided a systemic antioxidant protection but the significance of endogenous ecdysteroids in the management of oxidative stress remains to be shown.
给成年无翅红蝽（雄性平均体重29.6毫克，雌性平均体重36.9毫克）注射38皮摩尔百草枯（1,1'-二甲基-4,4'-联吡啶鎓），会导致微粒体脑部分的脂质过氧化和蛋白质羰基化显著升高，以及膜流动性下降。氧化应激的另一个表现是脑提取物中还原型谷胱甘肽池的消耗和γ-谷氨酰转肽酶活性的降低。同时注射1皮摩尔20-羟基蜕皮激素（20E）可抵消百草枯对大脑的损害作用。20E抑制脂质过氧化和蛋白质羰基的形成，改善微粒体膜流动性的变化，提高还原型谷胱甘肽水平，并上调γ-谷氨酰转肽酶的活性。在机体水平上，20E减少了注射百草枯引起的三种有害影响：一种血液蛋白的消失、繁殖力和卵孵化率的抑制以及成年寿命的缩短。数据表明，20E提供了全身抗氧化保护，但内源性蜕皮甾体在氧化应激管理中的重要性仍有待证明。
