RESUMO
The differentiation of megakaryoblasts into megakaryocytes and their release of blood platelets are complex and poorly understood processes. As an aid to investigate this process several cell lines with megakaryocyte characteristics have been established. One of these cell lines is the rat promegakaryoblast-like (RPM) cell line established by Cicoria and Hempling and used by others to describe maturation processes in megakaryocytes. We have used this cell line to study the synthesis of platelet-specific marker proteins. Severe difficulties led us to perform control experiments to confirm earlier findings. We were unable to confirm several of the previous reports, and we conclude that this particular cell line should not be recommended for the study of megakaryoblast differentiation.