Figure 5.

[³H]Thymidine incorporation assay. Amount of [³H]thymidine incorporation in rat-1a cell clones expressing κ-WT or Ro2 in the presence of dynorphin A(1–13) (DynA) or spiradoline (Spirad) as indicated. Ro2 plus spiradoline, plus pertussis toxin (PTX) 200 ng/ml is indicated by ○. The value for 100% is the value for the highest dose of spiradoline for each receptor. The basal point is untreated cells. Data in are expressed as mean ± SD of duplicate determinations in a single experiment; three additional experiments gave similar results.