title: The effects of 2-bromopalmitate on the fatty acid composition in differentiating adipocytes of red sea bream (Pagrus major).
abstract: To determine whether external factors affect the adipogenic function of fish adipocytes, the effects of 2-bromopalmitate (a PPAR agonist) on the fatty acid composition in differentiating adipocytes of red sea bream were investigated in vitro. In the presence of 2-bromopalmitate, the red sea bream adipocytes were differentiated and the effects on the fatty acid composition and the adipogenic gene expression were analyzed. With the level of 2-bromopalmitate, the content of 16:1n-7, a delta-9 desaturation product, increased in association with the increase in a stearoyl CoA desaturase (SCD) gene expression level while the triglyceride accumulation was not affected. Subsequently, the effects on the bioconversion of the n-3 and n-6 fatty acids, which are main series of dietary essential fatty acids, were examined. In the presence of 300 microM of 18:3n-3 or 18:2n-6, red sea bream stromal-vascular cells accumulated the lipid in the cytoplasm within 3 days by the fatty acid uptake with the increase of corresponding fatty acid contents. Furthermore, in both the 18:3n-3 and 18:2n-6 stored cells, the products of delta-6 desaturation (18:4n-3 and 18:3n-6, respectively) and C(18-20) elongation (20:3n-3 and 20:2n-6, respectively) were detected. However, neither the delta-6 desatutration nor C(18-20) elongation of 18:3n-3 and 18:2n-6 were enhanced by 2-bromopalmitate treatment. In conclusion, the results indicate that the adipocyte function in fish, e.g. adipogenic gene expression and fatty acid composition, can be modified by external factors and a main effect of 2-bromopalmitate is the increase in the content of delta-9 desaturation product by stimulating the SCD gene expression.
authors.affiliation: National Research Institute of Aquaculture, Minami-Ise, Mie, Japan. hiromi@fra.affrc.go.jp
authors.forename: Hiromi
authors.initials: H
authors.lastname: Oku
authors.forename: Masaharu
authors.initials: M
authors.lastname: Tokuda
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Umino
mesh_terms: D017667:Adipocytes / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D008401:Gas Chromatography-Mass Spectrometry; D019787:Linoleic Acid / Q000032:analysis / Q000378:metabolism*; D010168:Palmitates / Q000494:pharmacology*; D021541:Sea Bream / Q000378:metabolism*; D014280:Triglycerides / Q000032:analysis; D017962:alpha-Linolenic Acid / Q000032:analysis / Q000378:metabolism*
chemical_list: D010168:Palmitates; D014280:Triglycerides; D017962:alpha-Linolenic Acid; C022776:2-bromopalmitate; D019787:Linoleic Acid