The effect of a tubercle bacillary lipid on the clearance rate of colloidal carbon from the blood of rabbits.

Rabbits were given a single i.v. injection of 10 mg. of a tubercle bacillary lipid known to be active in increasing antibody production. The animals were given an i.v. injection of colloidal carbon at intervals after the lipid and the rates of clearance from the blood measured over the next 30 min. A triphasic curve resulted. For the first hr after injection of the lipid no effect was obtained on the rate of removal of the carbon. From the 2-12th hr the phagocytic index increased enormously for 5 min. after injection of the carbon, then became nearly normal. From the 18th hr the phagocytic index increased to a maximum at about 36 hr and then began to revert to normal.