Physiology

Study data from University of Alaska update knowledge of metabolism

"Estimation of diets using the quantitative fatty acid signature analysis (QFASA) model requires the use of calibration coefficients to account for predator metabolism of individual FAs. We conducted a captive feeding experiment to determine the effects of a 50% reduction in food intake on growth rate and adipose tissue FA signatures of tufted puffin (Fratercula cirrhata) nestlings, a species that routinely experiences food restriction during growth. FA signatures of chicks fed low- and high-calorie diets both exhibited a change in composition in response to the dietary shift with the direction of change in the composition of individual FAs matching the direction of change in the dietary FAs. Despite a growth rate in the restricted nestlings that was 38% of those in the well-fed group, rates of FA turnover were not different between high and low-calorie treatments, and turnover was close to, but not entirely complete, after 27 days on both high-calorie and restricted diets. FA signatures of tufted puffin nestlings were significantly affected by caloric restriction, but these effects were much less pronounced than those of dietary turnover, and calibration coefficients of puffins fed low and high-calorie diets were highly correlated," wrote C.T. Williams and colleagues, University of Alaska.

The researchers concluded: "Our results demonstrate that changes in physiological state can affect FA metabolism, but future research is required to better understand whether the size of these effects is sufficient to substantially alter diet estimation using the QFASA model.."

Williams and colleagues published their study in the Journal of Comparative Physiology B - Biochemical Systemic and Environmental Physiology (The effects of diet and caloric restriction on adipose tissue fatty acid signatures of tufted puffin (Fratercula cirrhata) nestlings. Journal of Comparative Physiology B - Biochemical Systemic and Environmental Physiology, 2009;179(6):711-720).

For additional information, contact C.T. Williams, University of Alaska SE, Dept. of Biology, Juneau, AK 99801, USA.

Publisher contact information for the Journal of Comparative Physiology B - Biochemical Systemic and Environmental Physiology is: Springer Heidelberg, Tiergartenstrasse 17, D-69121 Heidelberg, Germany.

Keywords: United States, Juneau, Biochemical, Comparative Physiology, Metabolism, University of Alaska.

This article was prepared by Life Science Weekly editors from staff and other reports. Copyright 2009, Life Science Weekly via NewsRx.com.