Uptake of broxaterol by cultured human cells

The mechanism of uptake of the sympathomimetic drug broxaterol by Chang liver and HepG2 cell lines was investigated. When cells were incubated in the presence of low concentrations of broxaterol cell cultures take up (t1/2 = 5-10 min) and, depending on the experimental conditions, accumulate the drug such that the intracellular concentration is over 200-1000 times that in the incubation medium. The uptake was saturable and influenced by the presence of sodium and variations in external pH. These data may represent a model for tissue uptake in vivo in an attempt to investigate that selective uptake of broxaterol is involved in withdrawal of the molecule during drug therapy.