title: Enhanced binding and degradation of the C1q subcomponent of complement by thioglycollate-stimulated guinea pig peritoneal macrophages.
abstract: Expression of C1q receptors on the plasma membrane of thioglycollate-stimulated guinea pig peritoneal exudate macrophages increased 1.54 times as compared to unstimulated controls. A Scatchard plot of the binding of 125I-C1q to the cells revealed that the binding is a result of an increase in the number of receptors and not to an increased affinity of the receptors. Thioglycollate-activated macrophages were found to be 1.6 times more active than nonactivated macrophages in the binding of 125I-C1q at 4 degrees C. The enhanced binding of 125I-C1q by activated peritoneal macrophages was reflected in an increase in the amount of 125I-C1q degraded by these cells as compared to resident peritoneal macrophages. This suggests that stimulation of phagocytic cells leads to an increase in the expression of C1q receptors and to a concomitant increase in the uptake and degradation of C1q.
mesh_terms: D000818:Animals; D003166:Complement Activating Enzymes / Q000378:metabolism*; D015922:Complement C1q; D006168:Guinea Pigs; D007249:Inflammation / Q000276:immunology; D008262:Macrophage Activation; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism; D008562:Membrane Glycoproteins; D010529:Peritoneal Cavity / Q000166:cytology; D011951:Receptors, Complement / Q000378:metabolism; D013864:Thioglycolates / Q000494:pharmacology
chemical_list: D008562:Membrane Glycoproteins; D011951:Receptors, Complement; D013864:Thioglycolates; C032402:complement 1q receptor; D015922:Complement C1q; D003166:Complement Activating Enzymes