Fig. 2. Effect of cyclic stretching on the expression of mRNA for C/EBPs and PPARs during the induction period. Cells were grown in induction medium containing DEX, MIX, INS and FBS (DEX/MIX/INS) with or without cyclic stretching. (A) The representative results of hybridization experiments showing quantitatively amplified PCR products. The total RNA of 3T3-L1 cells at different times during the respective induction periods was subjected to quantitative RT-PCR and blots of the PCR products were hybridized with DIG-labelled cDNA probes corresponding to each target mRNA.(B-F) Summarized data showing the expression of C/EBP (B), C/EBPß (C), C/EBPd (D), PPAR₁ (E), and PPAR₂ (F) by RT-PCR analysis. Each value is expressed as relative amount of mRNA for target gene compared with that expressed in undifferentiated cells (i.e. expression before induction, Pre=1), which was calculated using a standard curve of a serial dilution of cDNA form the undifferentiated 3T3-L1 cells. The white bar represents the cells before induction (Pre), the black bar represents the cells not subjected to stretching (Rest) and the grey bar represents the cells subjected to cyclic stretching (Stretch; at 130%, 1 Hz) at different time points during induction (n=3 each). ^*P<0.05 vs control (0 hours); ^**P<0.01 vs control (0 hours); P<0.05 vs without cyclic stretching (rest), corresponding to each time point; P<0.01 vs without cyclic stretching (rest), corresponding to each time point.