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

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

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5min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24h,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。

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.