Effect of dietary arginine on growth, intestinal enzyme activities and gene expression in muscle, hepatopancreas and intestine of juvenile Jian carp (Cyprinus carpio var. Jian).
The present study was conducted to test the hypothesis that dietary arginine promotes digestion and absorption capacity, and, thus, enhances fish growth. This improvement might be related to the target of rapamycin (TOR) and eIF4E-binding protein (4E-BP). A total of 1200 juvenile Jian carp, Cyprinus carpio var. Jian, with an average initial weight of 6.33 (SE 0.03) g, were fed with diets containing graded concentrations of arginine, namely, 9.8 (control), 12.7, 16.1, 18.5, 21.9 and 24.5 g arginine/kg diet for 9 weeks. An real-time quantitative PCR analysis was performed to determine the relative expression of TOR and 4E-BP in fish muscle, hepatopancreas and intestine. Dietary arginine increased (P < 0.05): (1) glutamate-oxaloacetate transaminase and glutamate-pyruvate transaminase activities in muscle and hepatopancreas; (2) intestine and hepatopancreas protein content, folds height, and trypsin, chymotrypsin, lipase, Na⁺/K⁺-ATPase, alkaline phosphatase, γ-glutamyl transpeptidase and creatine kinase activities in intestine; (3) Lactobacillus counts; (4) relative expression of TOR in the muscle, hepatopancreas and distal intestine (DI); (5) relative expression of 4E-BP in proximal intestine (PI) and mid-intestine (MI), as compared with the control group. In contrast, dietary arginine reduced (P < 0.05): (1) plasma ammonia content; (2) Aeromonas hydrophila and Escherichia coli counts; (3) relative expression of TOR in PI and MI; (4) relative expression of 4E-BP in the muscle, hepatopancreas and DI. The arginine requirement estimated by specific growth rate using quadratic regression analysis was found to be 18.0 g/kg diet. These results indicate that arginine improved fish growth, digestive and absorptive ability and regulated the expression of TOR and 4E-BP genes.
Animal Nutrition Institute, Sichuan Agricultural University, Sichuan, Ya'an, People's Republic of China.
Gangfu
G
Chen
Lin
L
Feng
Shengyao
S
Kuang
Yang
Y
Liu
Jun
J
Jiang
Kai
K
Hu
Weidan
W
Jiang
Shuhong
S
Li
Ling
L
Tang
Xiaoqiu
X
Zhou
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D000641:Ammonia / Q000097:blood; D000818:Animals; D017756:Aquaculture; D001120:Arginine / Q000008:administration & dosage* / Q000009:adverse effects / Q000378:metabolism; D002347:Carps / Q000097:blood / Q000254:growth & development* / Q000378:metabolism / Q000382:microbiology; D015169:Colony Count, Microbial; D004063:Digestion; D039561:Eukaryotic Initiation Factor-4E / Q000378:metabolism; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D043143:Hepatopancreas / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000201:enzymology* / Q000254:growth & development / Q000382:microbiology; D007778:Lactobacillus / Q000254:growth & development / Q000302:isolation & purification; D018482:Muscle, Skeletal / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D009928:Organ Specificity; D012333:RNA, Messenger / Q000378:metabolism; D011897:Random Allocation; D058570:TOR Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D000637:Transaminases / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D039561:Eukaryotic Initiation Factor-4E; D029941:Fish Proteins; D012333:RNA, Messenger; D000641:Ammonia; D001120:Arginine; D000637:Transaminases; D058570:TOR Serine-Threonine Kinases