Differential effects of β-glucan on oxidative stress, inflammation and copper transport in two intestinal regions of large yellow croaker Larimichthys crocea under acute copper stress

摘要

The aim of the present study was to evaluate investigate the effects of beta-glucan on oxidative stress, inflammation and copper transport in two intestinal regions of large yellow croaker under acute copper stress. Fish were injected with beta-glucan at a dose of 0 or 5 mg kg(-1) body weight on 6, 4 and 2 days before exposed to 0 and 368 fig Cu L-1 for 48 h. Biochemical indicators (MDA, Cu content, MTs protein levels, Cu/Zn-SOD, CAT and iNOS activities), gene expressions of oxidative stresses (Cu/Zn-SOD, CAT, Nrf2, MTs and MTF-1), inflammatory responses (NF-kappa B, iNOS, IL-1 beta, IL-6 and TNF-alpha) and Cu transporters (ATP7A, ATP7B and CTR1) were determined. In the anterior intestine, beta-glucan increased MTs levels, activities of Cu/Zn-SOD, CAT and iNOS, mRNA levels of MTs, CAT, iNOS, ATP7A and ATP7B, and reduced Cu content and CTR1 gene expression to inhibite Cu-induced MDA. But beta-glucan had no effect on inflammatory gene expressions. In the mid intestine, beta-glucan increased activities of Cu/Zn-SOD and iNOS, mRNA levels of Cu/Zn-SOD, CAT and iNOS to maintain MDA content. However, unlike the anterior intestine, beta-glucan had no effect on Cu transporter gene expressions. Furthermore, transcription factors (Nrf2, NF-kappa B and MTF-1) paralleled with their target genes in the mid intestine, but no correlation was observed between NF-kappa B and IL-1 beta and TNF-alpha gene expressions in the anterior intestine. In conclusion, our results unambiguously showed that beta-glucan induced oxidative stress, inflammation and copper transport were varied between the anterior and mid intestines of fish under Cu stress.