Inhibitory activity of heated ewe serum for ewe and ram serum complement

Authors: Jonas W, Stankiewicz M
Publication: New Zealand Veterinary Journal, Volume 31, Issue 4, pp 41-44, Apr 1983
Publisher: Taylor and Francis

Animal type: Livestock, Production animal, Ruminant, Sheep
Subject Terms: Circulatory system/haematology, Clinical pathology, Diagnostic procedures, Immune system/immunology
Article class: Scientific Article

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Abstract: In the presence of an indicator antigen-antibody complex, the complement (C) activity in ewe and ram serum was reduced or abolished by addition of ewe serum that had been heated at 56°C for 10 minutes. Pre-incubation of heated ewe serum at 39°C for 30 minutes with the C source prior to addition of the indicator system or addition at the same time caused similar reductions in C activity. Results from the haemolytic, conglutinating and haemagglutinating activities studied indicate that the ewe serum inhibitor(s) reacts with activated classical or alternative activating pathway components and/or the third component of C (C3). The presence of a potent C inhibitor(s) in ewe serum probably accounts for the low sheep C titres with some assay systems. As the heated ewe serum did not appear to activate ewe or ram C perse, it is more appropriate to regard it as `inhibitory` rather than `anticomplementary`.

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