title: In vivo turnover studies of C-reactive protein.
abstract: The in vivo plasma clearance rate of the acute phase reactant C-reactive protein (CRP) was studied in mice and rats. The clearance rate of 125I-human CRP in mice and 125I-rat CRP in rats showed a T1/2 of approximately 4 h. The T1/2 was independent of circulating levels of CRP and was not affected by the presence of C-polysaccharide (CPS), a ligand to which CRP binds. However, in mice receiving sufficient CPS, more radioactivity localized to the spleen compared to mice receiving 125I-CRP only. 125I-CPS was rapidly cleared at the same rate by normal mice and by mice undergoing an acute phase response while rats cleared 125I-CPS more slowly despite having high circulating CRP concentrations. These findings suggest that CRP does not provide a mechanism for extremely rapid clearance of its ligands from the circulation, although the handling and subsequent fate of these ligands may be affected.
mesh_terms: D000818:Animals; D002097:C-Reactive Protein / Q000378:metabolism*; D002846:Chromatography, Affinity; D005260:Female; D008657:Metabolic Clearance Rate; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D011135:Polysaccharides, Bacterial / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D011135:Polysaccharides, Bacterial; C027158:polysaccharide C-substance (Streptococcus); D002097:C-Reactive Protein