title: Regulation of dietary glutamine on the growth, intestinal function, immunity and antioxidant capacity of sea cucumber Apostichopus japonicus (Selenka).
abstract: The present study examined the effects of dietary glutamine (Gln) on the growth, intestinal function, immunity and antioxidant capacity of sea cucumber Apostichopus japonicus (Selenka). The specific growth rate, intestinal morphology, activity of digestive enzymes, activity and gene expression of lysozyme and antioxidative enzymes of the sea cucumbers were determined after feeding 5 experimental diets with additions of increasing levels of Gln (at 0%, 0.4%, 0.8%,1.2% and 1.6%, respectively) for 60 days. We discovered that the specific growth rate of the sea cucumbers in 0.4%, 0.8% and 1.2% groups increased 35.3%, 27.3% and 24.1%, respectively, compared to the control (0%) group with significant differences. Dietary Gln can improve the intestinal function of the sea cucumbers by increasing the activities of trypsin and lipase in the intestine and the villus height and villus density of the intestine, eventhough significant differences were not observed in some groups. 0.4%-0.8% of dietary Gln can significantly increase the activity of lysozyme (LSZ) in the coelomic fluid of the sea cucumbers. Significant improvements were observed on the SOD activity in coelomic fluid of the sea cucumbers fed diets supplemented with 0.4%-1.6% of Gln compared to the control group. Similarly, the CAT activity in coelomic fluid of the sea cucumbers significantly increased in 0.8%, 1.2% and 1.6% groups compared to the control and 0.4% groups. Change pattern of the activity of CAT was consistent with the change pattern of the expression of CAT gene, indicating the dietary Gln can up-regulate the expression of CAT gene and consequently promote the secretion of CAT. However, the down-regulation of the expression of SOD gene by dietary Gln were observed in almost all of the treatment groups, which is in contrast with the change pattern of the activity of SOD, indicating the negative feedback regulation of the secretion of SOD on the expression of SOD gene. In summary, the suitable supplementation levels of Gln in diets of sea cucumber A. japonicus are 0.4%-0.8%, based on the effectiveness of dietary Gln on the growth, intestinal function, immunity and antioxidant capacity of the sea cucumbers.
authors.affiliation: Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China.
authors.forename: Haibo
authors.initials: H
authors.lastname: Yu
authors.affiliation: Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China. Electronic address: qfgao@ouc.edu.cn.
authors.forename: Qinfeng
authors.initials: Q
authors.lastname: Gao
authors.affiliation: Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China.
authors.forename: Shuanglin
authors.initials: S
authors.lastname: Dong
authors.affiliation: Key Laboratory of Marine Drugs, Ministry of Education, Ocean University of China, Qingdao 266003, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Lan
authors.affiliation: School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn 36849, USA.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Ye
authors.affiliation: Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wen
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D005973:Glutamine / Q000008:administration & dosage / Q000378:metabolism*; D007113:Immunity, Innate; D007422:Intestines / Q000502:physiology; D047528:Stichopus / Q000254:growth & development / Q000276:immunology / Q000502:physiology*
chemical_list: D000975:Antioxidants; D005973:Glutamine
keywords: Antioxidant capacity; Apostichopus japonicus; Digestive enzymes; Gene expression; Glutamine; Intestinal morphology; Lysozyme