两种多糖对齐口裂腹鱼生长、血清抗氧化指标及组织镉积累量的影响

为研究0.40%硫酸软骨素(CS)和酸解氧化魔芋葡甘露聚糖(AOKGM)对齐口裂腹鱼生长、抗氧化及镉胁迫之后抗氧化性能和组织中(肝脏、肾脏和鳃)镉积累量的影响,实验选取450尾初始体质量为(98.00±8.54) g的齐口裂腹鱼分为3组(对照组、AOKGM组和CS组),进行为期8周的养殖实验,然后每个实验组选取120尾齐口裂腹鱼暴露在镉环境中,进行15 d的镉胁迫实验(镉浓度分别为0、0.10、0.25和1.00 mg/L),分别对2种多糖在齐口裂腹鱼生长及抗氧化性能方面进行相关研究,以及分析镉胁迫后2种多糖的抗氧化性能和组织中镉的积累量。结果显示,与对照组相比,2种多糖显著提高了齐口裂腹鱼的特定生长率、脾体指数和头肾指数;粗脂肪、灰分和粗蛋白质相对于对照组也有显著影响。CS和AOKGM均显著提高血清超氧化物歧化酶(SOD)活性、总蛋白(TP)和一氧化氮(NO)含量,降低葡萄糖(GLU)含量;CS能显著提高血清谷胱甘肽过氧化物酶(GSH-Px)活性和胆固醇(TC)含量,降低丙二醛(MDA)含量。结果显示,与镉浓度0 mg/L相比,MDA含量在镉浓度为1.00 mg/L时最高,SOD活性在镉浓度为1.00 mg/L时最低,GSH-Px活性在镉浓度为0.25和1.00 mg/L时显著降低,NO含量在镉浓度为0.25和1.00 mg/L时显著升高。镉胁迫实验中,与对照组相比,2种多糖组的SOD活性显著提高,MDA含量降低;NO含量在镉浓度0.10～1.00 mg/L胁迫时显著降低;CS显著提高镉浓度0.10、0.25 mg/L胁迫下的GSH-Px活性,AOKGM组GSH-Px活性在镉浓度为0.25、1.00 mg/L时显著高于对照组。与无镉组对比,齐口裂腹鱼肝脏、肾脏和鳃镉的积累量在各镉浓度下显著增加;而CS和AOKGM均能够降低机体组织镉含量。研究表明,在饲料中添加0.40%的2种多糖均能提高齐口裂腹鱼生长、抗氧化性能,降低镉胁迫下鱼体肝脏、肾脏和鳃中镉的积累量,缓解镉对齐口裂腹鱼造成的氧化损伤,为齐口裂腹鱼饲料的开发提供新的理论依据。

Effects of two kinds of polysaccharides on growth, serum antioxidant indices and tissue cadmium accumulation of Schizothorax prenanti

The present study aimed to determine the effects of dietary 0.40% chondroitin sulfate (CS) and 0.40% acidolysis oxidated konjac glucomannan (AOKGM) added to feed for 8 weeks on growth, antioxidant indices and tissues (liver, kidney and gill) cadmium accumulation of Schizothorax prenanti. A total of 450 healthy S. prenanti individuals with similar body weight (98.00±8.54) g were randomly assigned to three groups with three replicates per group and 50 fish per replicate. After 8 weeks, the growth and the serum antioxidant indices of S. prenanti were determined. In addition, the cadmium stress test was carried out for 15 days (0, 0.10, 0.25, 1.00 mg/L), and the serum antioxidant indices and tissues cadmium accumulation of fish under cadmium stress were determined. The results were as follows: compared with the control group, specific growth rate (SGR), spleen index (SI) and head kidney index (HKI) were increased when the diets were supplemented with CS and AOKGM. Additionally, the crude lipid, crude protein and ash content of muscles were significantly increased when both polysaccharides were added. Compared with the control group, the serum superoxide dismutase (SOD) activity, total protein (TP) and nitric oxide (NO) content of the fish were significantly increased, and glucose (GLU) content of fish was significantly decreased when diets were supplemented with both polysaccharides. The glutathione peroxidase (GSH-Px) activity and cholesterol (TC) content of fish were significantly increased, and malondialdehyde (MDA) content of fish was significantly decreased when CS was added to the diet. Compared with 0 mg/L cadmium, MDA content was the highest and SOD activity was the lowest at 1.00 mg/L cadmium, GSH-Px activity was significantly decreased and NO content was significantly increased at 0.25 and 1.00 mg/L cadmium. Compared with 0 mg/L cadmium, the SOD activity significantly increased, and MDA content significantly decreased, while NO content significantly decreased at 0.10-1.00 mg/L cadmium when diets were supplemented with both polysaccharides. CS significantly increased GSH-Px activity at 0.10 and 0.25 mg/L cadmium. AOKGM significantly increased GSH-Px activity at 0.25 and 1.00 mg/L cadmium. Compared with 0 mg/L cadmium, the cadmium accumulation in liver, kidney and gill of fish significantly increased at different cadmium concentrations, while CS and AOKGM decreased the cadmium content of tissues. Taken together, the results showed that 0.40% CS and AOKGM had certain effects on the growth and antioxidant capacity of S. prenanti, and it reduced the cadmium accumulation in tissues. This study provides a new theoretical basis for the development of nutritional feed for S. prenanti.