Ossified Particles in the Peripheral Circulation of Young and Old Male Fischer-344 Rats Following Bone Marrow Ablation and Interleukin-1 Receptor Antagonism

Plasma concentrations of IL-1α and IL-1β varied with age and condition. Treatment with the IL-1RA in old rats exacerbated the number of OSP in circulation, with the combined treatment (i.e., IL-1RA+BMA) having the most dramatic effects. The majority of circulating OSP were 15-30 µm in diameter, i.e., diameters amenable to embolism.