The role of platelet activating factor released during cutaneous immediate allergic reactoion on atopic dermatitis

1991 Fiscal Year Final Research Report Summary

• Project/Area Number: 02670479
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: Dermatology
• Research Institution: Hiroshima University
• Principal Investigator: NUMATA Tsunemi Hiroshima University, University Hospital, Assistant Professor, 医学部附属病院, 講師 (70127687)
• Co-Investigator(Kenkyū-buntansha): KAWAMOTO Hiroaki Hiroshima University, University Hospital, Research Associate, 医学部附属病院, 助手 (10234139) ; YAMADA Satoru Hiroshima University, School of Medicine, Research Associate, 医学部, 助手 (90158189)
• Project Period (FY): 1990 – 1991
• Keywords: Platelet activating factor / Immediate allergic reaction / Atopic dermatitis

Research Abstract

A clear explanation has not been made about the etiology of atopic dermatitis. Although histamine rereased from mast cells plays a critical role in cutaneous immediate allergic reaction, our previous studies have shown release of prostaglandin D_2, leukotriene B_4 and peptide leukotrienes from sensitized guinea pig and human skin during cutaneous immediate allergic reaction.
In the present studies, in order to investigate the role of platelet activating factor(PAF)in atopic dermatitis, the release of PAF during cutaneous immediate allergic reaction was investigated. The abdominal skin of guinea pig sensitized with egg albumin was cleaned of subcutaneous tissue and cut into slices. The skin slices were incubated in Tyrode solution containing lOOmug/ml egg albumin at 37ﾟC for 20 min. The levels of PAF in the supern tanta after incubation with antigen were measured by radio-immunoassay. The levels of PAF were not significantly increased the supernatanta although there was significant increase in the levels of LTB_4.
As there is a possibility that PAF produced in the skin tissue by antigen might not be released into the supertants, the level of PAF in the skin slices collected after incubation with antigen were measured. The level of PAF in the skin slices were also not significantly increased. These results suggest that during cutaneous immediate allergic reaction, PAF might not be produced in the skin tissue and have no significant role in producing atopic dermatitis. But in the present study, acetylhydrolase which could easily metabolize PAF was detected in the reaction medium. This might suggest the possibility that PAF produced by the antigen in the skin tissue might be metabolized by acetylhydrolase quickly.