THE EFFECT OF METABOLIC BY-PRODUCTS ON ANIMAL CELLS IN CULTURE

ABSTRACT 1. Eight independent cell lines which were examined showed considerable variation in sensitivity to added ammonia. The growth of some cell lines was not inhibited by the concentrations of ammonia that normally accumulate in culture. 2. The growth inhibitory effect of ammonium chloride increases at higher culture pH values. This data suggests that NH 3 rather than NH 4 + may be the toxic form of the molecule in the culture medium. 3. Although the addition of lactate upto 20 mM can cause some growth inhibition, lower concentrations can have a sparing effect on anmonia toxicity. Data indicates that this nay be related to the intracellular sequestration of ammonia and formation of alanine.