초록
This study was designed to determine the effects of the insulin-like growth factor (IGF-1) and estradiol $17-{\beta}$ on the in vitro proliferation of stromal vascular cell from Hanwoo omental, subcutaneous, intermuscular and intramuscular adipose tissues. Cells were cultured in M199+20% newborn calf serum and the proliferation of cells was measured by direct microscopic cell counting and change of genomic DNA amount. Cell numbers increased slightly over the first 72 hour of culture and then increased greatly, regardless of adipose tissue depots. In IGF-1 treatment, the number of omental preadipocytes maintained highest level from the beginning to the 20th day of culture. However, in estradiol-$17{\beta}$ treatment, those tended to be lower than the control from the beginning of culture and significantly lower at the 24th day. When IGF-1 was added to subcutaneous preadipocytes, the numbers of cells were higher from 11th day than those from other treatments, although there was no statistical significance. For intermuscular preadipocytes treated with IGF-1, its numbers were significantly (p<0.05) higher at 11th day, and in the other days it showed a similar tendency to those of the subcutaneous tissue. In this experiment, preadipocytes were taken from 24 month old fully matured steers and the highest proliferation rate was shown in intramuscular tissue followed by those of subcutaneous preadipocytes. Addition of $5{\mu}M$ estradiol-$17{\beta}$ to the growth medium failed to promote the replication of Hanwoo preadipocytes, as indicated by direct cell counts and total genomic DNA content. As the culture period proceeded, the amounts of DNA were increased, but the patterns of increment were not consistent with the results of cell numbers.