The medium dependence of nuclear interactions is described by an effective Lagrangian characterized by density dependent meson nucleon couplings. The density dependence of the coupling parameters of the \sigma , \omega , \delta , and \rho mesons is deduced by reproducing the nucleon self-energy resulting from the relativistic Brueckner--Hartree--Fock approach at each density for symmetric and asymmetric nuclear matter. The inclusion of the density dependent isovector mesons couplings, \delta and \rho , affects the density and charge distributions of finite nuclei. The results are discussed and compared with experimental data and with results from similar approaches.

PACS numbers: 21.60.--n, 21.65.+f, 21.10.--k