Neutral amino acid transport and in vitro aging.

  title={Neutral amino acid transport and in vitro aging.},
  author={Richard B. Newton and Jerome L. Sullivan and A G Debusk},
  journal={Mechanisms of ageing and development},
  volume={27 1},
Human fibroblasts possess five distinguishable systems for amino acid transport. Initial rates for three of these decline with in vitro age. The decline most noticeably affects the L system, whose rate for L-phenylalanine transport at 10 microM declines by 44% between the 27th and 39th population doubling levels. Accumulation of L-phenylalanine is similarly affected. The insensitivity of older cells to reduction of the amino acid concentration in culture medium casts doubt on possible… CONTINUE READING