Metallic mercury (0.04 ml) injected into the foot pad of rats induced a consistent inflammatory reaction, which at 4 h showed oedema but no cellular infiltration or vascular changes. The lesions exhibited lymphocytic infiltration, vasodilatation and haemorrhages at 24 and 48 h, and often became cystic after 2–3 weeks, before healing. The oedema volume at 4 h was used to test anti‐inflammatory activity of drugs.
Cortisone, phenylbutazone, indomethacin, acetylsalicylic acid, flufenamic acid and propranolol exhibited potent, dose‐related anti‐inflammatory activity. Aminopyrine, chloroquine and chlorpromazine were only moderately effective. Dimercaprol, adrenaline, and to some extent, mepyramine also inhibited mercury‐induced oedema.
This simple model of acute inñammation may be useful for preliminary tests of anti‐inflammatory activity.