HISTIDINE DECARBOXYLASE ACTIVITY OF AUTOGRAFTED AND ALLOGRAFTED RAT SKIN

Intracellular histamine formation from histidine decarboxylase enzyme activity was measured in autografts and allografts of full thickness rat skin from 1-21 days after grafting by a sensitive and specific isotope dilution method. Histidine decarboxylase activity of autografted skin was elevated 8-fold with two peaks at days 1 and 4 followed by prompt return toward levels of normal skin allografts. The histidine decarboxylase activity of allografts was one-half that of autografted skin at days 1 and 4. After day 4, there was a marked increase in histidine decarboxylase activity of allografts to a peak 33-fold elevation at day 10, followed by a return toward normal levels. Autografted skin was more adherent to the graft bed at day 1 than was allografted skin. The divergent patterns of the two types of graft with respect to alterations in intracellular histamine formation may be of significance in the biological processes of tissue histocompatability recognition and acceptance or rejection. © 1969 by The Williams and Wilkins Co.