Glucose use in fish · Carbohydrate utilization by the working muscle of rainbow trout
FP7 — People (Marie Curie Actions)
- Duration
- 2012-11-01 → 2013-10-31
- EU contribution
- €15,000
- Participants
- 1
- Scheme
- MC-IIFR
Lines connect the coordinator with its partners.
Results in brief
Carbohydrate utilization by the working muscle of rainbow trout
Commercial fish diets commonly contain a high percentage of carbohydrates, despite fishes´ apparent low natural capacity to utilize them. This is an important area for research, because a high proportion of carbohydrates in the diet can provide readily available glucose to supply most of the energy needed for maintenance, so that a greater proportion of protein can be reserved to build up muscle tissue. We have previously shown that exercise can increase carbohydrate utilization in salmonids (rainbow trout and brown trout), a carnivorous group of fish cultured world-wide. In this part of the project we studied further the use of carbohydrate rich-diets in pejerrey (Odonthestis bonariensis) an omnivorous species with great potential for aquaculture in Argentina. The goal of this part of the project is strengthen the understanding of the effects of the use of high carbohydrate feeds on the physiology of pejerrey by studying its metabolic response to that condition. We are currently studying how glucose homeostasis is regulated in this species, analyzing metabolic changes that may occur in these fish under different dietary conditions, including the regulation of glucose transporters at transcriptional level in target tissues. The results of this research may have a positive impact on the optimal use of food resources available in the region for feeding farmed fish species. If carbohydrates could be effectively utilized to spare the use of dietary protein, the benefits to the aquaculture industry in Argentina would be significant. The development of optimized diets will make possible a decrease in feed costs and a reduction in the output of harmful nitrogenous wastes, while still meeting the world’s ever increasing demand for commercially farmed fish.
Data: CORDIS, © European Union
Project objective
Carbohydrate-rich diets are frequently used in the commercial farming of fish. However, fish do not appear to have an elevated capacity to clear a high load of glucose from their circulation. Special attention has been directed towards the study of the physiological responses to such carbohydrate-rich feeding. Skeletal muscles play a key role in glucose homeostasis in mammals, and exercise has a noticeable effect in lowering plasma glucose. This effect is caused by an up-regulation of glucose transport mediated by GLUT4 in skeletal muscles in response to exercise. However, the exact mediating mechanism in the modulation of glucose transport in skeletal muscle has not been entirely characterized in vertebrates. Moreover, fish are an excellent model for the research of mechanisms involved in changes of the GLUT glucose transporters produced by exercise because they have anatomically separated red and white muscle masses, which allow the measurement of fibre-type-specific responses. I hypothesize that sustained exercise can be used to enhance carbohydrate expenditure in fish, increasing their natural capacity to clear and utilize plasma glucose by the contracting muscle. I will investigate this possibility, placing a special emphasis on the study of the cellular and molecular mechanisms regulating the GLUT-1 and -4 glucose transporters in white and red muscles. Changes in patterns for gene expression using a microarray platform and key biochemical parameters will also be measured in red and white muscles of rainbow trout after four weeks of sustained swimming. I expect that the results obtained from this research will help us to understand how glucose is regulated in fish. This knowledge could be transferred to European companies, leading to more efficient and environmentally conscious feeding practices in the rapidly growing and economic important aquaculture sector.
Original text from CORDIS.
Participants
- CONSEJO NACIONAL DE INVESTIGACIONES CIENTIFICAS Y TECNICAS (CONICET) · Buenos AiresCoordinatorArgentina
Links
Data: CORDIS, © European Union