Pharmacological comparison of the immune and non-immune inflammations induced by picryl chloride and oxazolone in mice.

Picryl chloride applied to the ears of Swiss mice induced a clearcut primary irritation inflammation (maximal after 3 to 6 hr) and after contact sensitization performed 7 days before a delayed hypersensitivity reaction. Oxazolone produced only a weak primary irritation reaction. After contact sensitization in the same conditions as above, oxazolone induced an immune response that was already substantial 3 to 6 hr after the challenge and generally reached a maximum after 24 hr. We tried to alter these four types of inflammation (the primary irritation and delayed hypersensitivity to picryl chloride, and the 6-hr and 24-hr phases of hypersensitivity to oxazolone) by various types of compounds administered cutaneously or sytemically. Mepyramine, methysergide, cimetidine, disodium cromoglycate, phenylbutazone, and acetylsalicylic acid reduced to varying degrees after cutaneous application the primary irritation and the delayed hypersensitivity inflammation induced by picryl chloride. Methysergide was the only one of these drugs that on topical application clearly reduced the immune response to oxazolone (decrease in the 6-hr phase). After systemic administration, these same drugs had no effect on the four types of reaction. Both the corticosteroids tested (hydrocortisone acetate and desonide) reduced all the inflammations to various degrees and were always more active (particularly desonide) when applied topically than when administered systemically. On the other hand indomethacin, which inhibited all types of inflammation, was more active when administered systemically. Study of the kinetics and trials of pharmacological modulation of the various reactions induced by picryl chloride and oxazolone in Swiss mice provided evidence of differences in behavior between the two agents.