RESUMO
Abstract; Aim To explore the differences of 2,4-dinitrofluoro- benzene ( DNFB) -induced allergic contact demiatitis (ACD) models with different modeling cycles for the study of skin itch¬ing and inflammation, so as to provide reference and basis for the identification and selection of a more suitable animal model.Methods DNFB was used as a sensitizer, 0.5% DNFB was used to build a 2-week ACD model, and after 5-day sensitiza¬tion, the modeling site was administered once every other day and repeated four times.0.15% DNFB was used to build a 5- week ACD model, and after one week of treatment, DNFB was applied to the modeling site twice a week for four weeks.Behav¬ioral videos were recorded for 60 minutes alter each application of DNFB on the back of the neck for 24 hours.After modeling, Ig-K levels in serum were detected by KLISA, and the skin at the modeling site was stained for histopathology and observed.Results The entire modeling process of both modeled ACD mice was accompanied by severe scratching response after re¬peated skin exposure to DNFB, and the number of scratching significantly increased (P <0.01).Histopathological results showed epidermal thickening ( P < 0.01 ) , hyperkeratosis and inflammatory cell infiltration (P <0.01) in both modeling meth¬ods, and senmi Ig-F levels were significantly elevated ( P < 0.01).Conclusions The contact dennatitis model caused by DNFB is very stable, showing typical pruritus symptoms, severe dermatitis injury and inflammatory immune response, but the 5- week model may have more typical symptoms and allow enough time to observe the effect of the drug, which provides further ex¬perimental basis and evidence for pruritus and inflammation re¬lated drug research.