Abstract: | The antiviral agent phosphonoacetic acid inhibits growth of Tetrahymena thermophila at concentrations comparable to those inhibiting growth of other eukaryotic cells, with 50% inhibition at 0.5 mM phosphonoacetic acid. The compound is cytotoxk to Tetrahymena at concentrations greater than 2.0 mM. When a culture of Tetrahymena the growth of which was totally inhibited by 2.0 mM phosphonoacetic acid was diluted with fresh medium, growth resumed in an exponential, rather than synchronous, fashion. 2–14C]phosphonoacetic acid is not metabolized by Tetrahymena. |