QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Terjesen, B. F. Articles by Dabrowski, K. Search for Related Content PubMed PubMed Citation Articles by Terjesen, B. F. Articles by Dabrowski, K.

---

Biochemical and Molecular Actions of Nutrients

Lipoic Acid and Ascorbic Acid Affect Plasma Free Amino Acids Selectively in the Teleost Fish Pacu (Piaractus mesopotamicus)¹

Bendik F. Terjesen^*,,**, Kwan Park^*,, Marcelo B. Tesser^*,, Maria C. Portella, Yongfang Zhang^* and Konrad Dabrowski^*,2

^* School of Natural Resources, The Ohio State University, Columbus, OH 43210; AKVAFORSK, Institute of Aquaculture Research, Sunndalsøra, Norway; ^** Aquaculture Protein Centre, Ås, Norway; Department of Aquatic Life Medicine, College of Ocean Science and Technology, Kunsan National University, Soryong-Dong, Kunsan City, Chonbuk, South Korea; and São Paulo State University Aquaculture Center, Jaboticabal-SP, Brazil

²To whom correspondence should be addressed. E-mail: dabrowski.1{at}osu.edu.

Most studies on the antioxidants, lipoic acid (LA) and ascorbic acid (AA), focused on species that, unlike teleost fish, are not scurvy-prone, and are able to synthesize AA. The antioxidant properties of LA may make it useful in aquaculture nutrition, but several effects must first be investigated, and we address here plasma free amino acids (FAA). In mammals, LA and AA in high doses were claimed to alter plasma FAA profile; to our knowledge, however, no data are available in fish. We therefore studied the effects of dietary LA and AA on plasma FAA in the South American teleost fish pacu, which is being used increasingly in aquaculture. LA treatment decreased concentrations of 18 of 23 individual FAA; specifically, dispensable and total FAA were significantly affected. Ornithine was elevated (+26%) in LA-treated fish and significantly decreased ratios of plasma [Arg]/[Orn] and other individual [FAA]/[Orn] were observed. LA and AA both affected sulfur FAA concentrations. Plasma cystine levels were significantly increased in the LA-supplemented groups. AA had little effect on most amino acids, and no interaction with LA was detected. AA supplementation did, however, significantly lower taurine (–42%) and cystathionine (–31%) levels in plasma. No effect on the branched chain:aromatic amino acid ratios was observed. The data indicate that at the dietary level studied, LA and AA independently affect selected plasma FAA in pacu, and suggest that any use of LA in particular as a dietary supplement should take into account an altered plasma FAA profile.

KEY WORDS: • teleost • lipoic acid • ascorbic acid • antioxidant • free amino acids