嗜水气单胞菌感染对背角无齿蚌5种免疫相关酶活力的影响

THE CHANGES OF FIVE IMMUNE ENZYMES FROM ANODONTA WOODIANA INFECTED WITH AEROMONAS HYDROPHILA

本研究以背角无齿蚌为材料,利用嗜水气单胞菌为诱导刺激物,对背角无齿蚌进行注射感染,在注射后3、6、12、24、48h分别取血淋巴、肝胰腺,测定其超氧化物歧化酶(SOD)、酚氧化酶(PO)、酸性磷酸酶(ACP)、碱性磷酸酶(AKP)及过氧化氢酶(CAT)的活力,并研究各项酶活力的变化规律。结果表明:除3h外,实验组肝胰腺的SOD活力均不同程度地高于对照组;血清实验组的PO活力开始显著高于对照组,然后降低,而肝胰腺实验组的PO活力持续高于对照组;另外,与对照组相比,实验组中血淋巴与肝胰腺的ACP、AKP和CAT活力在不同的时间段虽然有所增强,但两者之间无显著差异。因此,认为SOD、PO活性可以作为背角无齿蚌免疫抗病功能指标参数,而ACP、AKP及CAT活性能否作为该参数还有待于进一步研究。

It is suggested that the status and function in the internal defence mechanisms on immune enzymes in seashell have been noticed by more and more scholars in the world at present. Understanding the activation or effect factors of the enzymatic system can enable the evaluation of the health of breed aquatic. The activation of the enzymatic system by bacte- rial or fungal components is an additional clue of the involvement of these enzymes in invertebrate immune defence mechanisms. This paper reported the activities of selected enzymes in haemolymph and hepatopancreas from Anodonta woodiana infected by Aeromonas hydrophila. Healthy Anodonta woodiana were collected from Yangzi Island near Poyang Lake, with body length of 13.58 ± 1.12 cm and height of 8.34 ± 0.91cm. Haemolymph and hepatopancreas were extracted at 3h, 6h, 12h, 24h and 48h from the Anodonta woodiana injected with Aeromonas hydrophila（ 1.6 ×10^8cell/mL） and 0.9 % NaCl solution （control group） respectively. The levels of Superoxide dismutase （SOD）, Phenoloxidase （PO）, Alkaline phosphatase （AKP）, Acid phosphatase （ACP） and Catalase （CAT） were tested. The results showed that the activities of SOD from haemolymph injected by Aeromonas hydrophila could be significantly higher than that in control at 3h, 12h and 48h respectively, but only at 48h from hepatopancreas. PO activities in serum were notable higher than that in control at 3h and 6h and had the highest level at 3h after injection, then decreased appreciably, however, PO activities in hepatopancreas increased significantly at 3h. It proved that the activities of SOD and PO in the haemolymph and hepatopancreas of Anodonta woodiana could be induced significantly elevation by Aeromonas hydrophila. While there was no overt difference between injection and control group for the changes of ACP activities, which might indicate that the effect of stimulation on Anodonta woodiana with Aeromonas hydrophila was not obvious, so that, it might not stimulate acute increase and release of lysosomes. The same explanation was fit for the change of AKP activities which increased slightly the whole time in the haemolymph and significantly in the hepatopancreas at 3h. In addition, the changes of CAT activities in the haemolymph of Anodonta woodiana were not obvious even it restrained notably in the hepatopancreas at 24h and 48h, the enzymatic responses were compared with other studies and the possible reasons were discussed. It showed that activities of SOD and PO may be used as an indicator on immune disease-resistance, while further research will be needed to understand the activities, functions and mechanism of AKP, ACP and CAT.