Decreased membrane-bound ATP-hydrolytic activity in psoriatic epidermis*


  • *

    This study was in part presented at the one hundred and second meeting of the Vereinigung Rheinisch-Westfälischer Dermatologen, Bonn, 27 October 1973.

†Reprint requests to: Dr G. Mahrle, University Skin Clinic, 5 Köln-Lindenthal, West Germany.


Previous studies from our laboratory suggested that architectural alterations of the cell membranes may have a major significance in the pathogenesis of psoriasis. Consequently, the membrane-bound Mg++ activated ATP-hydrolytic activity was investigated in normal and psoriatic epidermis under the electron microscope.

The present study revealed that, in contrast to normal epidermis, only minimal ATP-hydrolytic activity is present on the cell membranes of psoriatic keratinocytes. This finding may reflect either a diminished attachment of substrate on the altered cell surface or an enzyme defect of the cell membrane. In both cases the reduced interaction between ATP and membrane-bound ATP-hydrolysing enzymes represents a functional membrane disorder of the psoriatic keratinocyte, presumably resulting in an insufficient utilization of ATP for active transport mechanisms on the cell surface.