In vivo effects of cellulose sulphate on plasma kininogen, complement and inflammation.

1. The in vivo action of cellulose sulphate was studied in an attempt to clarify the role of complement and kinin formation in inflammation.2. Inflammatory oedema was produced in the rat paw by heat (45.5 degrees C), and on the ear by xylene. The oedema was assessed by comparing the ratio of fresh wet weight to dry weight of corresponding injured and non-injured parts.3. Following cellulose sulphate (6.5 mg/kg i.v.), plasma kininogen concentrations were promptly reduced by 90% or more. The reduction in complement titres was statistically significant and ranged from 17 to 65%. No toxic effects were observed. The oedema caused by heat or xylene was not reduced in these rats.4. Cellulose sulphate (80 mg/kg i.p.) given over 3 days depleted plasma kininogen by about 90%, but reduced complement titres only slightly. These rats gained less weight and their condition was poor. Blood clotting was impaired and widespread haemorrhages were found. Heat and xylene produced significantly less oedema than in control rats. This diminished response is attributed to toxic side effects of cellulose sulphate, rather than depleted plasma kininogen and reduced plasma complement.5. The results suggest that the inflammatory reactions to thermal and chemical injury can fully develop when plasma kininogen and complement are lowered.