Effect of surface digestion and metabolic inhibitors on appearance of ferritin in guinea pig erythroblasts in vitro: evidence for the production of apoferritin on the erythroblast cell membrane.

Short-term cultures of guinea pig eryththesizing cells only slightly. In the roblasts permitted observation on the presence of potassium cyanide, which micropinocytosis (rhopheocytosis) of ferinhibits iron transport markedly, ferritin ritin. In the presence of enzymes that atincreased two-seven times over controls. tack the cell surface (neuraminidase and The data are compatible with the notrypsin) or of an inhibitor of RNA syntion that apoferritin is made on or near thesis (puromycin), accumulation of ferthe cell surface in response to an excess ritin in the micropinocytotic vesicle was of iron which accumulates on the cell reduced. No change was seen in pressurface due to failure or overloading of ence of lead nitrate, which inhibits the normal transport mechanism. transport of iron into hemoglobin-syn-