Increased accumulation of a lipophilic cation (tetraphenylphosphonium) in human embryo fibroblasts after infection with cytomegalovirus.

The distribution of a lipophilic cation, tetraphenylphosphonium (TPP+), has been used to monitor changes in mitochondrial and plasma membrane potentials within human embryo fibroblasts infected with human cytomegalovirus. An increase in TPP+ accumulation was observed throughout the whole viral replication cycle, beginning 6 h after infection. This effect requires an active viral DNA and seems to be dependent on the early transcription of the viral genome. In the early phase of viral replication, the increase in TPP+ accumulation is insensitive to mitochondrial inhibitors and sensitive to ouabain, and could be due to a hyperpolarization of the plasma membrane. Later during the infectious cycle, enhanced accumulation of the lipophilic cation is sensitive to mitochondrial inhibitors.