title: Effect of dietary carbohydrate on non-specific immune response, hepatic antioxidative abilities and disease resistance of juvenile golden pompano (Trachinotus ovatus).
abstract: The present study was conducted to investigate the effects of dietary carbohydrate (CHO) levels on non-specific immune responses, hepatic antioxidative status and disease resistance of juvenile golden pompano. Fish were fed six isonitrogenous and isoenergetic diets containing various CHO levels for 8 weeks. After the feeding trial, fish were challenged by Vibrio harveyi and survival rate was recorded for the next 12 days. Plasma total protein and albumin content, respiratory burst activity, alkaline phosphatase, slightly increased with dietary starch level from 0% to 16.8%, but significantly decreased at dietary starch levels of 16.8%-28%. Plasma lysozyme, complement 3 and complement 4 levels increased with increasing dietary carbohydrate up to 11.2% and then declined (P < 0.05). Contrary to glutamic-oxalacetic transaminase and triiodothyronine, plasma cortisol content increased with increasing dietary carbohydrate up to 22.4%, and then levelled off. The hepatic total antioxidative capacity, reduced glutathione and catalase levels reached the peak at the fish fed diet with 16.8% carbohydrate (P < 0.05). This also held true for hepatic superoxide dismutase activities, whereas the hepatic malondialdehyde content of fish fed dietary starch level of 16.8% was significantly lower than that of fish fed no CHO diet, but showed little difference (P > 0.05) with those of the other treatments. After challenge, fish fed 11.2% and 16.8% dietary CHO showed higher survival rate than that of fish in 0% CHO group (P < 0.05). However, survival rate showed little difference among 0%, 5.6%, 22.4% and 28% CHO groups (P > 0.05). The results of this study suggest that ingestion of 11.2-16.8% dietary CHO can enhance the non-specific immune responses, increase the hepatic antioxidant abilities, and improve resistance to V. harveyi infection of juvenile golden pompano.
authors.affiliation: Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, the South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, PR China; South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China; Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, PR China. Electronic address: chpzhou@163.com.
authors.forename: Chuanpeng
authors.initials: C
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, PR China. Electronic address: gexp@ffrc.cn.
authors.forename: Xianping
authors.initials: X
authors.lastname: Ge
authors.affiliation: Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, the South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, PR China. Electronic address: linheizhao@163.com.
authors.forename: Heizhao
authors.initials: H
authors.lastname: Lin
authors.affiliation: Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, the South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, PR China.
authors.forename: Jin
authors.initials: J
authors.lastname: Niu
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002374:Catalase / Q000097:blood; D003165:Complement System Proteins / Q000276:immunology; D004040:Dietary Carbohydrates / Q000009:adverse effects / Q000494:pharmacology*; D060467:Disease Resistance / Q000187:drug effects* / Q000276:immunology; D005393:Fish Diseases / Q000276:immunology* / Q000382:microbiology*; D005978:Glutathione / Q000097:blood; D006854:Hydrocortisone / Q000097:blood; D008099:Liver / Q000187:drug effects* / Q000276:immunology; D009113:Muramidase / Q000097:blood; D010473:Perciformes; D016897:Respiratory Burst / Q000187:drug effects; D013482:Superoxide Dismutase / Q000097:blood; D014735:Vibrio Infections / Q000276:immunology / Q000662:veterinary*
chemical_list: D004040:Dietary Carbohydrates; D003165:Complement System Proteins; D002374:Catalase; D013482:Superoxide Dismutase; D009113:Muramidase; D005978:Glutathione; D006854:Hydrocortisone
keywords: Bacterial challenge; Dietary carbohydrate level; Hepatic antioxidative abilities; Non-specific immune responses; Trachinotus ovatus