Abstract: In order to investigate the effect and the mechanisms of the action of calcium channel blockers on routine contact dermatitis we first studied the effect of calcium channel blockers(nifedipine, diltiazem,verapamil and flunarizine) on DNCB-induced allergic contact dermatitis and croton oil-induced irritant contact dermatitis in BALB/c mice.The results showed that the reduction of ear swelling and infiltration of mononuclear cells in dermis induced by DNCB in mice were highly significant (P<0.01). But the changes of ear swelling and infiltration of mononuclear cells in dermis induced by croton oil in mice were not significant (P>0.05).Then,the effect of calcium channel blockers on lymphocyte trans-formation and IL2 production were measured with MTT colorimetric assay in vivo(flunarizine) and in vitro(nifedipine,diltiazem,verapamil) in mice.The results revealed That these drugs can all significantly inhibit lymphocyte transformation and IL2 production,either in vivo or in vitro.It is suggested that calcium channel blockers can inhibit DNCB-induced allergic contact dermatitis and had no significant effect on croton oil-induced irritant contact dermatitis in mice.It is the authors opinion that calcium channel blockers directly inhibit lymphocyte transformation and IL2 production and indirectly effect lymphocyte proliferation through inhibiting IL2.

Key words: Dermatitis,contact, Calcium channel blockers