The explant culture of pig skin after corneocyte layer stripping in vivo.

Adult pig skin was stripped of its horny layer by cellophane tape. At intervals over the next 4 days explant cultures were prepared from such areas. Growth displayed an initial rapid and secondary slower phase. Plating of explants immediately following the stripping gave rise to an increased rate of migration of cells from the explants during the first growth phase but a decreased second or proliferative growth phase. This was not present when plating was delayed 1 to 4 days after stripping. The growth fraction in cells of the stripped skin explant cultures was similar to that of unstripped controls. The diminished growth rate of the cells was due to prolongation of the mean cell cycle time. Thus, the hyperproliferative state induced in vivo after stripping did not maintain itself when transferred in vitro. This result is of importance concerning animal models for psoriasis and the influence a transfer to in vitro conditions may have on the hyperproliferative psoriatic epidermis.