Figure 1

PEG-ADI depletes extracellular arginine. A) Levels of arginine (nmol/100 μl) in tissue culture media of MIA-PaCa-2 or L3.3 cells when cultured in complete media (baseline), following transition to HBSS, or HBSS supplemented with citrulline and aspartate; B) Levels of amino acids in tissue culture medium of exponentially growing MIA-PaCa-2 cells (left) and 24 hrs after treatment with PEG-ADI (1 μg/ml) (right) with arrow denoting HPLC peak of arginine.