氨对重组中国仓鼠卵巢细胞生长及人红细胞生成素表达的影响

氨对重组中国仓鼠卵巢（CHO）细胞的生长具有明显的抑制作用，并遵循二级抑制模型，抑制常数Ka为41．5（mmol/L)^2，即当氨浓度为6．45mmol/L时，细胞的比生长速率下降到最大比生长速率的50％，在重组CHO细胞的批培养过程中，细胞密度和红细胞生成素浓度随着起始氨浓度的提高而下降，但存在一最适的氨浓度，在此浓度下，单位重组CHO细胞的EPO比生成速率最大。

Effects of Ammonia on the Growth and EPO Expression of Recombinant CHO Cells

The effects of ammonia on the growth of recombinant CHO cells and the expression of EPO were studied. The inhibition of ammonia over the growth of recombinant CHO cells follows the second order inhibition model, and the inhibition constant K a is 41.5(mmol/L) 2, i.e. the specific growth rate of cells reduced to the half of its maximum value at 6.45 mmol/L ammonia. It was shown that the cell density of recombinant CHO cells and EPO concentration in batch cultures with different initial ammonia concentrations reduced with the increase of ammonia concentrations. The specific production rate of EPO at 3.22 mmol/L ammonia was higher than those at others, showing that there was an optimum ammonia concentration at which the capacity of recombinant CHO cells expressing EPO was on the peak. These results may be helpful to optimize the production of EPO in the culture of recombinant CHO cells.