即时浸酸显著降低滞育家蚕卵的还原型与氧化型谷胱甘肽比值

即时浸酸在阻止家蚕Bombyx mori卵滞育发动的同时, 显著提高了家蚕卵H₂O₂含量。还原型谷胱甘肽（reduced glutathione, GSH）与氧化型谷胱甘肽（oxidized glutathione, GSSG）的比值是一种氧化胁迫状态的动态指标。为了调查即时浸酸是否造成滞育家蚕卵氧化胁迫, 本研究利用分光光度法分别测定了滞育家蚕卵和5 min即时浸酸滞育家蚕卵中GSH和GSSG含量以及谷胱甘肽转移酶（glutathione-S-transferase, GST）活性。结果表明: 处理后24 h, 即时浸酸处理家蚕卵的总谷胱甘肽（GSH+2GSSG）含量、 GSH含量、 GSSG含量、 GSH/GSSG比值和GST活性分别相当于同期滞育家蚕卵的204%, 78%, 550%, 14%和97%。据此推测, 即时浸酸在阻止滞育发动的同时, 可能通过促进GSH氧化为GSSG, 而显著降低了GSH/GSSG比值, 使家蚕卵处于过氧化状态。

Instant hydrochloride acid soaking reduces markedly the GSH/GSSG ratio in diapause eggs of the silkworm,Bombyx mori

In the silkworm, Bombyx mori, H₂O₂ significantly increases in diapause eggs when diapause initiation is prevented with instant hydrochloric acid (HCl) soaking. The ratio of the reduced glutathione (GSH)/oxidized glutathione (GSSG) is indicative of the oxidative stress. To investigate whether instant HCl soaking causes the oxidative stress in diapause eggs of the silkworm, GSH and GSSG levels and glutathione-S-transferase (GST) activities in diapause eggs soaked with HCl for 5 min at 24 h after oviposition were determined using spectrophotometric methods with those without soaking with HCl as the control. Total glutathione content (GSH+2GSSG), GSH content, GSSG content, GSH/GSSG ratio and GST activity in diapause eggs soaked with HCl were equal to 204%, 78%, 550%, 14% and 97% of those in unsoaked diapause eggs at 48 h after oviposition, respectively. It is so inferred that the marked decline of GSH/GSSG ratio in diapause eggs soaked with HCl is resulted from the stronger oxidation of GSH to GSSG, which causes the transition from the reducing conditions to the peroxidatic conditions.