两种多糖对日本沼虾酚氧化酶活力的影响

EFFECTS OF TWO KINDS OF POLYSACCHARIDE ON THE PHENOLOXIDASE ACTIVITY IN MACROBRACHIUM NIPPONENSE

在饲料中分别添加 1‰的云芝多糖和虫草多糖 ,对日本沼虾进行投喂 ,通过连续测定日本沼虾血清中的酚氧化酶活力 ,研究两种多糖对日本沼虾免疫机能的作用。结果表明 ,在平均水温为 2 3 8℃± 3 8℃时 ,云芝组、虫草组分别较对照组提高了 34 52 %、84 62 % ;在平均水温为 1 0 8± 2 4℃时 ,云芝组和虫草组分别较对照组提高了30 0 2 %、5 1 2 % ,因而云芝多糖和虫草多糖能明显地增强日本沼虾血清的酚氧化酶活力。另经实验表明 ,在王雷所确立的酚氧化酶活力的检测条件下 ,其PO活力为 8 3units/mL ,而在Horowitz所确立的检测条件下 ,其PO活力为2 90units/mL ,并且后者检测方法重复性好 ,能较好地反映日本沼虾的免疫状态。

Macrobrachium nipponense ,2.5-3g in body weight, was bought from aquaculture market in Wuhan, and then cultured in laboratory tank (65cm×45cm×34cm). The shrimps were kept in the tank for 7 days and fed with diet containing 1‰ Polysticus and Cordyceps polysaccharide. The haemolymph was then taken from the heart of M.Nipponense which were cultured for 1,4,7,14,21,28 days to determine the phenoloxidase (PO) activity. The results were as follows: 1 Acording to Wang Lei's method, the PO activity was 8.3 units/mL, while the PO activity was 290 units/mL by the Horowitz's method. Besides the high sensitivity, the latter had a better repetition than the former. Therefore, the Horowitz's method was better for responding the immune state of M.nipponense. 2 PO activity could be tested in the haemolymph of M.nipponense . There was little effect on the PO activity by adding SDS. It was clear that in the haemolymph PO was not present by the form of zymogen. 3 At high temperature (for example 23.8±3.8℃), M.nipponense had a vigorously ingestion, the PO activity of Polystictus and Cordyceps groups increased about 34.52% and 84.62%. Polystictus and Cordyceps polysaccharide had remarkable enhancement on the PO activity. While the increase of PO activity was 30.02% and 5.12%respectively in low water temperature. The enhancement of polysaccharide on the PO activity was not significant. The increase of PO activity indicated that Polystictus and Cordyceps polysaccharide could improve nonspecific immunity of the shrimps, which would be useful as a potential immunostimulant.