Effect of Rare Earth Elements on Proliferation and Fatty Acids Accumulation of 3T3-L1 Cells

The present study including two experiments was designed to determine the effect of media containing different rare earth elements (REE) on proliferation and fatty acids accumulation in 3T3-L1 cell cultures. In Experiment 1, 3T3-L1 preadipocytes in 96-well plates (1.5×10 cells/ml) were cultured with Dulbecco’s modified Eagle’s medium (DMEM) containing 10% fetal bovine serum (FBS) for 24 h. Then the media were changed to the following 10 different media for 48 h: DMEM containing 10% FBS for the control; the above media containing 5 μM, 10 μM or 15 μM of LaCl3, CeCl3 or the mixture of these REE chlorides. The proliferation rate of the cells was measured and compared by a non-isotope method-XTT method. In Experiment 2 the cells in 24-well plates (1.5×10 cells/ml) were cultured in DMEM containing 10% FBS for 7 days until confluent and then were changed to above DMEM containing dexamethasone, methyl-isobutylxanthine and insulin (DMI) for two days. Afterwards the media were changed to the 10 different media with REE supplements as in Experiment 1 and cultured for 6 days. The cells were then harvested for fatty acids analysis by gas chromatography. It was found that supplementation of La (5, 10 and 15 μM), Ce (5 μM and 15 μM) and the mixture REE (5, 10 and 15 μM) stimulated (p<0.05) the proliferation of 3T3-L1 preadipocytes (Experiment 1). In the differentiating 3T3-L1 cells supplementation of La (5 μM and 10 μM), Ce (5 μM) and the mixture REE (5 μM and 15 μM) decreased (p<0.05) the concentration of monounsaturated fatty acids (MUFA) per 10 cells, while the supplementation of La (5 μM), Ce (5 μM) and the mixture REE (15 μM) increased (p<0.05) the ratio of saturated fatty acids (SFA) to MUFA. These results indicate that the supplementation of REE to the media may affect proliferation, differentiation and lipogenesis rates of 3T3-L1 cells. However, the effect may depend upon the level or type of REE applied. (Asian-Aust. J. Anim. Sci. 2006. Vol 19, No. 1 : 119-125)