Both iron homeostasis and erythropoiesis are known to be affected by aging. Iron needs in mammals are met primarily by iron recycling from senescent red blood cells (RBCs), a task chiefly accomplished by red pulp macrophages (RPMs) in the spleen. Given that RPMs continuously process iron, their cellular functions might be susceptible to age-dependent decline, a possibility that has been unexplored to date. In our project, we identified a formation of undegradable iron- and heme-rich extracellular aggregates in the spleens of 10-11-month-old female mice. To better understand the origin of these aggregates, here, we performed: i) protein identification and intrasample quantification (iBAQ) of proteins of magnetically-isolated red pulp macrophages from spleens of two female 8-weeks-old C57BL/6J (maintained on a standard diet) and ii) label-free quantification of proteins of the splenic protein aggregates formed in the mouse spleen 24 hours after intraperitoneal iron dextran injection, using dextran-injected mice as a control. Two 8-week-old C57BL/6J mice per group were analyzed. This dataset is related to the project PXD032900, which describes quanytitative analysis of proteins in aggregates magnetically isolated from spleen of aged (standard or iron-reduced diet) and young mice (standard diet).