Abstract: We studied the effects of the culture medium of normal human PMN stimulated by PAF on the proliferation of human keratinocytes and the inhibition of PAF antagonist BN52021 on the proliferation by using serum-free cell culture technique.The results showed that the simple culture medium of PMN could promote the proliferation of keratinocytes (P<0.05),the pro liferation of the culture medium of PMN stimulated by PAF on keratinocytes was much stronger than that of the simple culture medium of PMN (P<0.01).BN52021 could obviously inhibit PAF from stimulating PMN that mediated the proliferation of keratinocytes.It is suggested that PAF and PMN play an important pathophysiological role in the inflammatory process and epidermal proliferation of psoriasis, and the using of PAF antagonists may be a new and effective treatment for psoriasis.

Key words: Neutrophils, Platelet activating factor Keratinocyte proliferation, Antagonist