title: Effect of conjugated linoleic acid type, treatment period, and dosage on differentiation of 3T3 cells.
abstract: This study was conducted to determine effect of CLA and linoleic acid (LA) on cell differentiation, cellular glycerol-3-phosphate dehydrogenase (GPDH) activity, and FA accumulation in differentiating 3T3-L1 cells (3 isomers x 3 treatment periods x 4 doses). The cells were cultured in 24-well plates for proliferation until confluence. Then they were treated with media containing 0, 10, 35, or 70 mg/L (0, 35, 125, or 250 mmol/L, respectively) of LA, cis9,trans11- or trans10,cis12-CLA during early (day 0-2), intermediate and late (day 3-8), or overall (day 0-8) differentiation periods. Dexamethasone, methyl-isobutylxanthine, and insulin were supplemented to the media only for the early period to induce the differentiation. On day 8 of postconfluence the cells were harvested for Oil Red O staining, analysis of GPDH activity, and determination of the FA Concentration. Cellular LA or CLA was found to accumulate in a dose-response manner, mainly during the intermediate/late period. Treatment with trans10,cis12-CLA lowered (P < 0.05) GPDH activity and the concentration of FA including palmitic acid (16:0) and palmitoleic acid (16:1), especially during the intermediate/late and overall periods, or whenever a high dose of 70 mg/L was applied. This also resulted in a higher (P < 0.05) ratio of saturated FA to monounsaturated FA. Treatment with LA or cis9,trans11-CLA lowered cellular FA only when they applied during the early period at a dose of 70 mg/L. The results demonstrated that the inhibitory effects of CLA on differentiation, GPDH activity, and FA accumulation of 3T3-L1 cells are dependent on the isomer type, treatment period, and dose.
authors.affiliation: Department of Animal Science, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan. moro_he@yahoo.com
authors.forename: M L
authors.initials: ML
authors.lastname: He
authors.forename: T M
authors.initials: TM
authors.lastname: Hnin
authors.forename: H
authors.initials: H
authors.lastname: Kuwayama
authors.forename: P S
authors.initials: PS
authors.lastname: Mir
authors.forename: E K
authors.initials: EK
authors.lastname: Okine
authors.forename: H
authors.initials: H
authors.lastname: Hidari
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005227:Fatty Acids / Q000032:analysis; D005993:Glycerolphosphate Dehydrogenase / Q000378:metabolism; D019787:Linoleic Acid / Q000494:pharmacology; D044243:Linoleic Acids, Conjugated / Q000494:pharmacology*; D051379:Mice; D013997:Time Factors
chemical_list: D005227:Fatty Acids; D044243:Linoleic Acids, Conjugated; D019787:Linoleic Acid; D005993:Glycerolphosphate Dehydrogenase