Pulse-chase analysis of recombinant wild-type (A) and Tokushima-type (B) HRG expressed in BHK cells. Transiently transfected BHK cells were pulse-labeled for 1 hour and chased for 0, 0.5, 1, 2, 4, and 8 hours. Labeled HRG in cell extracts and culture medium was immunoprecipitated and analyzed on SDS-PAGE. Left arrowheads indicate HRG bands within cells, and right arrowheads indicate HRG bands secreted into culture medium.