Late inflammatory swelling by carrageenan in rat's subcutaneous neck tissue

When injected subcutaneously in the dorsum of neck in albino rats, carrageenan produced inflammatory swelling which reached peak after about 16 hr. The occurrence of the peak inflammatory swelling was delayed but not significantly reduced in severity by aspirin or indomethacin which were administered repeatedly. Phenylbutazone significantly reduced and dexamethasone almost completely inhibited it. In rat hind paw model, subplantar carrageenan injection produced peak inflammatory swelling after about 4 hr which was significantly reduced by all anti-inflammatory drugs mentioned above. It is interesting that an inflammagen when injected at different sites in the same species elicits responses which differ in the time course and drug responses.