Threonine affects intestinal function, protein synthesis and gene expression of TOR in Jian carp (Cyprinus carpio var. Jian)

• Published in: PloS one 2013-07, Vol.8 (7), p.e69974-e69974
• Main Authors: Feng, Lin, Peng, Yan, Wu, Pei, Hu, Kai, Jiang, Wei-Dan, Liu, Yang, Jiang, Jun, Li, Shu-Hong, Zhou, Xiao-Qiu
• Format: Article
• Language: English
• Subjects: Absorptivity; Agriculture; Alkaline phosphatase; Ammonia; Ammonia - blood; Ammonia content; Animals; Biology; Carp; Carps - blood; Carps - physiology; Cell Differentiation; Cell Proliferation; Cells, Cultured; Cyprinus carpio jian; Diet; Differentiation; Digestion; Enterocytes; Enterocytes - cytology; Enterocytes - metabolism; Feed efficiency; Fish; Fish Proteins - genetics; Fish Proteins - metabolism; g-Glutamyltransferase; Gene expression; Gene Expression Regulation; Growth rate; Hepatopancreas; Intestine; Intestines - physiology; Kinases; Lipase; Materials Science; Medicine; Muscles; Na+/K+-exchanging ATPase; Nutrition; Protein Biosynthesis; Protein synthesis; Pyruvic acid; Regression analysis; Segments; Threonine; Threonine - metabolism; TOR Serine-Threonine Kinases - genetics; TOR Serine-Threonine Kinases - metabolism; Transaminase; Trypsin; Veterinary Science; γ-Glutamyltransferase
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0069974

This study aimed to investigate the effects of threonine (Thr) on the digestive and absorptive ability, proliferation and differentiation of enterocytes, and gene expression of juvenile Jian carp (Cyprinus carpio var. Jian). First, seven isonitrogenous diets containing graded levels of Thr (7.4-25.2 g/kg diet) were fed to the fishes for 60 days. Second, enterocyte proliferation and differentiation were assayed by culturing enterocytes with graded levels of Thr (0-275 mg/l) in vitro. Finally, enterocytes were cultured with 0 and 205 mg/l Thr to determine protein synthesis. The percent weight gain (PWG), specific growth rate, feed intake, feed efficiency, protein retention value, activities of trypsin, lipase and amylase, weights and protein contents of hepatopancreas and intestine, folds heights, activities of alkaline phosphatase (AKP), γ- glutamyl transpeptidase and Na(+)/K(+)-ATPase in all intestinal segments, glutamate-oxaloacetate transaminase (GOT) and glutamate-pyruvate transaminase (GPT) activities in hepatopancreas, and 4E-BP2 gene expression in muscle, hepatopancreas and intestinal segments were significantly enhanced by Thr (p