Glucocorticoid induction of proline oxidase in LLC-RK1 cells.

Dexamethasone induced proline oxidase in cultured LLC-RK1 cells, an epithelial cell line derived from rabbit kidney. The dexamethasone-mediated increase in enzyme activity was concentration and time dependent. Although the effect could be dissociated from cell growth and cell density, it was dependent on protein and RNA synthesis. A comparison of the enzyme isolated from control and dexamethasone-treated cells showed that the increased activity was not due to an alteration in the affinity of the enzyme for proline. These findings suggest that glucocorticoids induce the synthesis of proline oxidase in mammalian cells.