注射亲水性硅珠对棉铃虫血浆酚氧化酶活性的影响

Impact of injecting hydrophilic silica beads on phenoloxidase activity in Helicoverpa armigera haemolymph

昆虫通过细胞免疫和体液免疫的协同作用对入侵的异物做出防御反应。在不同时间向棉铃虫体内注射亲水性硅珠后 ,测定了血浆中酚氧化酶 (PO)的活性 ,同时研究了不同抑制剂和激活剂对注射硅珠后的酚氧化酶活性的影响。结果表明 ,注射亲水性硅珠后 ,棉铃虫血浆中酚氧化酶的活性明显升高。分别以牛胰蛋白酶和昆布多糖作为酚氧化酶原 (proPO)的激活剂 ,发现两者都可激活注射硅珠后血浆中的proPO。以牛胰蛋白酶激活时 ,随着注射硅珠后时间的延长 ,PO活性逐渐增高 ;而用昆布多糖激活后PO活性也明显升高 ,但注射硅珠后不同时间proPO被昆布多糖激活的情况基本相似。这些结果表明 ,在异物入侵后酚氧化酶原有很大程度的积累 ,并能被激活 ,协同细胞免疫抵御异物入侵。p NPGB和PTU几乎能完全抑制酚氧化酶的活性。

Insects use cellular and humoral immune systems to defend themselves from foreign bodies. We assayed the dynamics of plasma phenoloxidase (PO) activity in Helicoverpa armigera larvae after the injection of hydrophilic silica beads into the haemocoel, We also studied the effects of the activators trypsin and laminarin, and inhibitors p NPGB and PTU on PO activities in plasma after silica beads were injected. The results showed that PO activities increased markedly after the injection of silica beads. PO activities in plasma were increased by the presence of trypsin, but under similar conditions PO activities did not follow the same trend when activated by laminarin. There may be an accumulation of prophenoloxidases (proPO) after the intrusion of foreign objects causing proPO to be activated at the appropriate time. p NPGB and PTU can totally inhibit PO activities.