Analysis of epidermal growth. Tape stripping of skin and explant culture.

An explant culture model of epidermal cell growth is outlined. Based on sequential measurements of the radius of the outgrowth around the explant, the paper describes two phases of growth. In the first phase, growth depends on migration of cells out from the explant and on their subsequent proliferation by mitosis. This period occurs during the first week after explantation. At a certain point in time, migration ceases and during the following phase a linear increase in log cell number takes place. A mathematical analysis of the growth is outlined and necessary parameters described. In the system, migration and proliferation rates are determined and the latter related to cell kinetic parameters. This model of epidermal cell growth is used to describe the explant culture of pig skin after activating the skin in vivo by tape stripping. This leads to a mitotic burst which in the explants is shown by augmented migration of cells from the explant, when compared with control explants. The migration rate was no different from that of controls. The duration of migration was prolonged in the experimental group. The proliferation rate observed in these outgrowths was similar. Cell cycle time was 53 and 43 h in control and stripped skin cultures, respectively. An analysis of the model is given.