| Effects of chitooligosaccharides role in enhancing resistence the capacity of aquatic animal disease has been widely recognized by the aquaculture industry. However, the mechanism on chitooligosaccharides modulating the immunity of Yellow River carp is not clear up to now.In this experiment, the Yellow River carp was used to study effects of chitooligosaccharides on reproductions of head kidney macrophages in vitro, respiratory activities and phagocytic activities of LPS-induced head kidney macrophage from Yellow River carp, some indicators including inflammatory cytokines such as IL-1β, TNF-α, NO and immune enzymes like ACP, AKP, SOD, i-NOS were cited. On the other hand, by studying effects of chitooligosaccharides injection on serum inflammatory cytokines, such as IL-1β, TNF-α, NO, and immune enzymes like ACP, AKP, SOD, i-NOS were studied in LPS-induced Yellow River carp. The purpose of our experiments is to reveal the mechanism of chitooligosaccharides enhancing disease resistence against bacteria in Yellow River Carp, and provide some theoretical foundation for accurately using chitooligosaccharides in aquaculture, and even to promote the efficiency, healthy and sustainablity of development of Yellow River culture.There were 8 treatments in our first experiment, and each treatment had 6 replicates. Different chitooligosaccharides concentrations, including 0 μmol/L, 10 μmol/L, 20 μmol/L, 50 μmol/L, 80 μmol/L, 100 μmol/L, 200 μmol/L, and 500 μmol/L, were used to study effects of chitooligosaccharides concentrations on reproduction of head kidney macrophages in vitro. Results showed that chitooligosaccharides could stimulate the reproduction of macrophages significantly at lower concentrations 0 μmol/L~100 μmol/L. However, the promoting effects of chitooligosaccharides decreased when the concentration increased at 200 μmol/L, and no significant effects at 500 μmol/L(P>0.05). High concentrations of chitooligosaccharides could enhance respiratory burst activity of head kidney macrophages separated from Yellow River carp. Respiratory burst activities stimulated by 80 μmol/L, 100 μmol/L, 200 μmol/L chitooligosaccharides were significantly higher than those of control(P <0.05).There were 6 different treatments(LPS 0 μg/mL, COS 0 μmol/L, LPS 1 μg/mL+COS 0 μmol/L, LPS 1 μg/mL+COS 10 μmol/L, LPS 1 μg/mL+COS 50 μmol/L, LPS 1μg/mL+COS 100 μmol/L, LPS 0 μg/mL+COS 100 μmol/L), and 3 replicates in each treatment, about effects of chitooligosaccharides and LPS on head kidney macrophages from Yellow River carp in our second experiment. Results showed that chitooligosaccharides stimulation for 24 h had significantly reduced activities of i-NOS enzyme and some inflammatory cytokines, such as TNF-α, IL-1β, NO, inhibited over-expression of NO of macrophages, and enhanced the activities of ACP, AKP, T-SOD and other enzymes, then improved the immunity of the Yellow River carp.In the third experiment, there were six different treatments which included 4 replicates to evaluated effects of chitooligosaccharides by intraperitoneal injection on serum indicators in Yellow River carp. Fish in Control groups was injected 1 mL saline solution by intraperitoneal injection, COS(300 μg/mL) groups injected 0.5 mL COS and 0.5ml saline solution, LPS(10 μg/mL) groups injected 0.5 mL LPS and 0.5 mL saline solution, COS+LPS(50 μg/mL+10 μg/mL) groups injected 0.5 mL COS(50 μg/mL) and 0.5 mL LPS(10 μg/mL), COS+LPS(100 μg/mL+10 μg/mL) groups injected 0.5 mL COS(100 μg/mL) and 0.5 mL LPS(10 μg/mL)by C, COS+LPS(300 μg/mL+10 μg/mL) groups injected 0.5 mL COS(300 μg/mL) and 0.5 mL LPS(10 μg/mL) by intraperitoneal injection. Results showed that after injection of different concentrations of COS, activities of ACP, AKP, T-SOD of serum in fish were sigificantly higher than those of only injected LPS. COS by intraperitoneal injection could significantly inhibit production of TNF-α, IL-1β, NO, and activities of i-NOS, and the most significant inhibition appeared at the concentration of 300μg/m L(P<0.05). |
PDF Full Text Request