title: Electroimmunoassay of alpha-2-opsonic protein during reticuloendothelial blockade.
abstract: Physiological regulation of reticuloendothelial (RE) phagocytic activity by a plasma opsonic factor has been documented. In the recent study, serum levels of this alpha-2-opsonic protein in rats during colloid-induced RE blockade were measured utilizing an electroimmunoassay (Rocket immunoelectrophoresis) with monospecific antiserum to the purified alpha-2-glycoprotein. RE blockade was produced by the intravenous injection of the gelatinized "RE-test-lipid emulsion" at a dose of 50 mg/100 g body wt. The opsonic activity of serum at various intervals during colloid-induced RE blockade as measured by tissue slice bioassay manifested a high correlation (r = 0.98) with the serum opsonic protein concentration as measured by the electroimmunoassay. During RE blockade (30 min), there was a rapid depletion of the opsonic alpha-2-glycoprotein to 20% of the initial preinjection levels. Serum concentration of this glycoprotein remained low for at least 2-3 h after which time its concentration progressively increased with approximation of normal values by 6 h postblockade. Opsonic protein concentration at 24 h postinjection were significantly (P less than 0.05) elevated above controls. Thus, colloid-induced RE blockade is associated with the removal of this glycoprotein from the serum and recovery from RE blockade is accompanied by a restoration of opsonin levels. The electroimmunoassay can provide a sensitive technique to monitor this humoral factor known to exert a physiological control on the RE system.
mesh_terms: D000510:Alpha-Globulins; D000818:Animals; D003102:Colloids; D006023:Glycoproteins / Q000276:immunology; D007106:Immune Sera; D007118:Immunoassay; D007122:Immunoelectrophoresis; D008297:Male; D008954:Models, Biological; D012157:Mononuclear Phagocyte System / Q000187:drug effects*; D009895:Opsonin Proteins / Q000032:analysis* / Q000302:isolation & purification; D010587:Phagocytosis / Q000187:drug effects; D051381:Rats; D000511:alpha-Macroglobulins / Q000032:analysis*
chemical_list: D000510:Alpha-Globulins; D003102:Colloids; D006023:Glycoproteins; D007106:Immune Sera; D009895:Opsonin Proteins; D000511:alpha-Macroglobulins