title: Sheep serum complement sensitisation of sheep erythrocyte-rabbit antibody complexes for haemolysis by guinea-pig complement plus EDTA or Mg2+-EGTA.
abstract: Sheep erythrocyte (E)-rabbit antibody (A) complexes incubated with sheep serum diluted up to 1:5120 or 1:20480 and washed can be haemolysed by guinea-pig (g-p) serum (complement, C) containing EDTA or Mg2+-EGTA respectively as haemolytic finishing reagents. Sheep E carrying a high dose of rabbit A were necessary for this reaction, particularly with g-p C-EDTA. G-p serum (stored by freezing) was active as a haemolytic finishing reagent with both EDTA and Mg2+-EGTA. Reconstituted freeze-dried g-p serum (also stored by freezing) was haemolytically active with Mg2+-EGTA only. G-p serum preserved by Richardson's method did not function as a finishing reagent with EDTA or Mg2+-EGTA. A non-haemolytic prozone occurred with sheep E-rabbit A treated with dilutions of sheep serum or body fluid up to 1:160, particularly when g-p C (frozen)-EDTA was used as the finishing reagent. Sheep E-rabbit A were sensitized by serum, foetal lamb serum, pericardiac-, synovial- or ovarian follicle-fluids colostrum or milk for haemolysis by g-p C (frozen)-EDTA or -Mg2+-EGTA. With the C3 inhibitors cobra venom factor or salicylaldoxime, serum sensitisation of sheep E-rabbit A for haemolysis by g-p C (frozen)-EDTA or -Mg2+-EGTA was not blocked. Sensitisation by serum heated at 50 degrees C for 30 min (partial inactivation of C2) was incomplete. Inhibitors of C1 (antrypol, chelators of Ca2+ or heating serum at 56 degrees C for 30 min) partially or fully blocked sensitisation for haemolysis by both g-p C (frozen)-EDTA or -Mg2+-EGTA. These results show that at a minimum, components C1, C4 and C2 are present and functionally active in serum and some body fluids of sheep.
mesh_terms: D000818:Animals; D000936:Antigen-Antibody Complex / Q000276:immunology*; D001826:Body Fluids / Q000276:immunology; D003170:Complement Pathway, Alternative; D003165:Complement System Proteins / Q000276:immunology*; D004492:Edetic Acid; D004533:Egtazic Acid; D004912:Erythrocytes / Q000276:immunology*; D006168:Guinea Pigs; D006461:Hemolysis; D066298:In Vitro Techniques; D011817:Rabbits; D012756:Sheep
chemical_list: D000936:Antigen-Antibody Complex; D004533:Egtazic Acid; D003165:Complement System Proteins; D004492:Edetic Acid