British Journal of Nutrition

Full Papers

Metabolism and Metabolic Studies

Short-term docosapentaenoic acid (22 : 5n-3) supplementation increases tissue docosapentaenoic acid, DHA and EPA concentrations in rats

Gunveen Kaura1, Denovan P. Begga2a3, Daniel Barra3, Manohar Garga4, David Cameron-Smitha3 and Andrew J. Sinclaira1a3 c1

a1 Metabolic Research Unit, School of Exercise and Nutrition Sciences, Deakin University, Waurn Ponds 3217, Vic, Australia

a2 School of Psychological Science, La Trobe University, Bundoora 3086, Vic, Australia

a3 School of Exercise and Nutrition Sciences, Deakin University, 221 Burwood Highway, Burwood 3126, Vic, Australia

a4 School of Health Science, University of Newcastle, Callaghan, Newcastle 2308, NSW, Australia

Abstract

The metabolic fate of dietary n-3 docosapentaenoic acid (DPA) in mammals is currently unknown. The aim of the present study was to determine the extent of conversion of dietary DPA to DHA and EPA in rats. Four groups of male weanling Sprague–Dawley rats (aged 5 weeks) were given 50 mg of DPA, EPA, DHA or oleic acid, daily for 7 d by gavage. At the end of the treatment period, the tissues were analysed for concentrations of long-chain PUFA. DPA supplementation led to significant increases in DPA concentration in all tissues, with largest increase being in adipose (5-fold) and smallest increase being in brain (1·1-fold). DPA supplementation significantly increased the concentration of DHA in liver and the concentration of EPA in liver, heart and skeletal muscle, presumably by the process of retroconversion. EPA supplementation significantly increased the concentration of EPA and DPA in liver, heart and skeletal muscle and the DHA concentration in liver. DHA supplementation elevated the DHA levels in all tissues and EPA levels in the liver. Adipose was the main tissue site for accumulation of DPA, EPA and DHA. These data suggest that dietary DPA can be converted to DHA in the liver, in a short-term study, and that in addition it is partly retroconverted to EPA in liver, adipose, heart and skeletal muscle. Future studies should examine the physiological effect of DPA in tissues such as liver and heart.

(Received February 12 2009)

(Revised June 23 2009)

(Accepted June 24 2009)

(Online publication August 04 2009)

Correspondence:

c1 Corresponding author: Professor Andrew J. Sinclair, fax +61 3 9251 7282, email andrew.sinclair@deakin.edu.au

Footnotes

Abbreviations: AA, arachidonic acid; ALA, α-linolenic acid; DPA, docosapentaenoic acid; LCPn-3, long-chain n-3 PUFA

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