Ferritin synthesis in rat L-6 cells: response to iron challenge

The short term response of the L-6 cell line of rat skeletal myoblasts to elevated extracellular iron concentrations was studied. It was found in all cases that iron as the nitrilotriacetate (NTA) chelate was effective at donating iron to the cells and at stimulating ferritin synthesis. After 48 h in 50 microM ferric NTA, the cellular ferritin levels rose from an undetectable level to 1.11 (+/- 0.07) ng ferritin/microgram cell protein, or 0.1% of total cell protein. Similarly, the total iron in the cells rose under the same conditions from an unmeasurable level to plateau at over 10 fmol iron/cell. In addition, it was found that these cells synthesize ferritin in response to iron in a dose-dependent manner over a range of iron concentrations from 5-1000 microM. A sensitive and specific immunoradiometric assay for rat ferritin was used in these studies to quantitate ferritin in cell lysates.