Programming Effects Of High-carbohydrate Feeding Of Larvae On Adult Glucose Metabolism In Mandarin Fish, Grass Carp And Zebrafish

This paper is mainly from the viewpoint of early nutrition programming. In the present study, we used the three kinds of feeding habit fish:Zebrafish (Danio rerio, omnivorous), Grass carp(Ctenopharyngodon idellus, herbivorous), Mandarin fish (Siniperca chuatsi, carnivorous) to determine potential long-term persistent metabolic changes in carbohydrate utilisation and regulatory mechanism in their later life cycle through early nutritional programming (feeding high-carbohydrate diets) during an early sensitive period, reveals whether it can affect metabolism plasticity and the degree of influence.1 Programming effects of high-carbohydrate feeding of larvae on adult glucose metabolism in zebrafish, Danio rerioThe aim of the present study was to determine the potential long-term metabolic effects of early nutritional programming on carbohydrate utilisation in adult zebrafish {Danio rerio). High-carbohydrate diets were fed to fish during four ontogenetic stages: from the first-feeding stage to the end of the yolk-sac larval stage; from the first-feeding stage to 2 d after yolk-sac exhaustion; after yolk-sac exhaustion for 3 or 5 d. The carbohydrate stimuli significantly increased the body weight of the first-feeding groups in the short term. The expression of genes was differentially regulated by the early dietary intervention. The high-carbohydrate diets resulted in decreased plasma glucose levels in the adult fish. The mRNA levels and enzyme activities of glucokinase, pyruvate kinase, a-amylase and sodium-dependent glucose co-transporter 1 were up-regulated in the first-feeding groups. There was no significant change in the mRNA levels of glucose-6-phospha-tase (G6Pase) in any experimental group, and the activity of G6Pase enzyme in the FF-5 (first feeding to 2 d after yolk-sac exhaustion) group was significantly different from that of the other groups. The expression of phosphoenolpyruvate carboxykinase gene in all the groups was significantly decreased. In the examined early programming range, growth performance was not affected. Taken together, data reported herein indicate that the period ranging from the polyculture to the external feeding stage is an important window for potential modification of the long-term physiological functions. In conclusion, the present study demonstrates that it is possible to permanently modify carbohydrate digestion, transport and metabolism of adult zebrafish through early nutritional programming.2 Adaptations of hepatic glucose metabolism in grass carp (Ctenopharyngodon idellus) juveniles in relation to high carbohydrate during early feedingThe main objective of our work was to assess the effects of long-term persistent metabolic changes in carbohydrate utilization in juvenile grass carp through early larva short term manipulation (feeding high carbohydrate diets) during an early sensitive period. We chose to apply the rich carbohydrate dietary stimulus at two early post-hatching feeding stages. We tested growth, blood, gut histological study and mentioned key gene expression of glucose metabolism. Through early nutritional intervention during an early sensitive period can promote early growth of larvae, especially the FF-3 group of growth plasticity can last to childhood. After the experience of early opening period treatment, the grass carp fingerlings can regulate blood sugar levels more stable, increase glycogen storage capacity. The YE-7 group and the FF-10 group of muscle glycogen content decreased. After experiencing the early stages of a high-carbohydrate diet feeding conditions, intestinal morphology of juvenile grass carp have different variations. The intestinal mucosal folds of four experimental treatments are flattened and the number of folds is decrease. GK and FAS gene are highly expressed in the FF-3 group grass carp fingerlings through the treatments of early stages. We also found that long-term intake of high carbohydrate diet may lead to nutritional deficiencies, and ultimately produce disorders of glucose metabolism system. Current research shows that early intervention of high-carbohydrate diet during sensitive period can induce effective adaptation and potential ability of utilizing carbohydrate for grass carp fingerlings.3 Effect of glucose solution on growth and glucose metabolism of mandarin fish (Siniperca chuatsi) larvaeIn order to investigate the effect glucose solution on growth performance and glucose metabolism, the mandarin fish larvae were cultured in a certain concentration of glucose solution at three different stages of feeding. We observed the feeding behavior and tested the early growth performance and expression of glucose metabolism-related genes. In the open mouth feeding stage, the mandarin fish larvae often cluster together in practical production. With the growth of the larvae, they will randomly disperse in all corners of the independent water body. In the present study, however, clustering phenomenon of the experimental group still occurs at the end of the experiment, which may be affected by glucose solution. In terms of growth performance, the weight and body length of three experimental groups were lower than the control group, and the body length of the FF-3 group was significantly lower than the control group(P< 0.05). In terms of gene expression, GK gene expression of the FF-3 group was significantly lower than the control group and the other genes had no significant effect. The GK, PK, G6Pase, PEPCK, GS, FAS expression of the FF-5 group were significantly higher than the control. Six gene expression of the YE-2 group were not significantly different from the control group. In summary, we found that the expression of genes related to glucose metabolism was very active when the mandarin fish larvae experienced the period ranging from the polyculture to the external feeding stage.4 Effects of initial feeding on the growth and glucose metabolism of juvenile grass carp (Ctenopharynodon idellus)To investigate the effect of initial feeds on growth and carbohydrate metabolism in grass carp larvae, we fed grass carp larvae with three different diets during first 10 days in aquarium after hatching:high-carbohydrate feed (60% Maltodextrin), commercial feed and zooplankton (Rotifera). Then we used commercial feed to feed grass carp larvae for other fifty-six days at 25-27 ℃ to analyse the effect of initial feeds on growth, glucose metabolic and gene expression. The results indicated that the growth performance of grass carp larvae fed with zooplankton was significantly superiorto other treatment groups (P< 0.05) while the GK gene expression was much lower than that of treatment groups (P< 0.05), and there was no significant difference in the levels of blood glucose and hepatic glycogen content between the grass carp larvae fed with commercial feed and zooplankton. Compared with the grass carp larvae fed with commercial feed, the levels of blood glucose and hepatic glycogen content were much lower than the grass carp larvae fed with high-carbohydrate feed (P< 0.05), but the GK gene expression was up-regulated significantly (P< 0.05) and there was no significant difference in growth performance. This study suggests that feeding grass carp larvae with high-carbohydrate feed for a short time can improve glucose metabolism and increase glucose utilization.