Bradykinin and
kallidin are released during dermal injury and
inflammation as a result of activation of
kallikreins which cleave high- and
low-molecular weight kininogen (HMW and LMW
kininogen, respectively). In the skin,
kinins are involved, e.g., as co-
mitogens in cellular proliferation or in processes propagating
pain and
inflammation. The aim of our study was to investigate the specific occurrence of mRNAs for components of the kallikrein-kinin system in normal human skin and in skin biopsies of patients with selected
skin diseases (
psoriasis, lichenificated
atopic eczema, basalioma). In normal skin, reverse transcription polymerase chain reaction (RT-PCR) with specific primer pairs followed by separation of products by
polyacrylamide gel electrophoresis (PAGE) revealed the presence of mRNAs for
tissue kallikrein, for the B2 and the B1
bradykinin receptors, but not for
kininogen. In biopsies of lichenificated
atopic eczema and basalioma, additionally, the mRNAs for HMW and LMW
kininogen were detected, whereas in psoriatic skin
mRNA for HMW
kininogen was not expressed. These differences in
mRNA expression may reflect the different contribution of kallikrein-kinin system components to the maintenance of chronic
skin diseases like
psoriasis. In acute dermal reactions occurring in lichenificated
atopic eczema or in basalioma, tissue
mRNA for HMW
kininogen appears to be arisen from sources not pre-existing in normal skin.