The binding of platinum ethylenediamine dichloride to proteins, in vitro and in vivo.

The binding to proteins of platinum ethylenediamine dichloride (PtenCl2) labelled with carbon-14 has been studied in vitro and in vivo. The metal complex binds to proteins in plasma with a half-time of about 1 h and is distributed over all protein classes. At pharmacologically relevant levels the binding of platinum does not affect the biological function of the protein, e.g. the immunoglobins. Although the in vitro toxicity of PtenCl2 is decreased by binding to the proteins of the culture medium, it has not yet proved possible to determine whether binding in vivo, e.g. to tumour cytosol proteins, leads to loss in toxicity and whether it is reversible.