Research article

The mathematics of tanning

Josef Thingnes^1,2 , Leiv Øyehaug^1,2 , Eivind Hovig^4,5,6 and Stig W Omholt^1,3

¹Centre for Integrative Genetics (CIGENE), Norwegian University of Life Sciences (UMB), PO Box 5003, 1432 Ås, Norway

²Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences (UMB), PO Box 5003, 1432 Ås, Norway

³Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, PO Box 5003, 1432 Ås, Norway

⁴Department of Tumor Biology, Institute for Cancer Research, Norwegian Radium Hospital, Montebello, 0310 Oslo, Norway

⁵Department of Medical Informatics, Norwegian Radium Hospital, Montebello, 0310 Oslo, Norway

⁶Department of Informatics, University of Oslo, PO Box 1080 Blindern, 0316 Oslo, Norway

author email corresponding author email

BMC Systems Biology 2009, 3:60doi:10.1186/1752-0509-3-60

Published:	9 June 2009

Abstract

Background

The pigment melanin is produced by specialized cells, called melanocytes. In healthy skin, melanocytes are sparsely spread among the other cell types in the basal layer of the epidermis. Sun tanning results from an UV-induced increase in the release of melanin to neighbouring keratinocytes, the major cell type component of the epidermis as well as redistribution of melanin among these cells. Here we provide a mathematical conceptualization of our current knowledge of the tanning response, in terms of a dynamic model. The resolution level of the model is tuned to available data, and its primary focus is to describe the tanning response following UV exposure.

Results

The model appears capable of accounting for available experimental data on the tanning response in different skin and photo types. It predicts that the thickness of the epidermal layer and how far the melanocyte dendrites grow out in the epidermal layers after UV exposure influence the tanning response substantially.

Conclusion

Despite the paucity of experimental validation data the model is constrained enough to serve as a foundation for the establishment of a theoretical-experimental research programme aimed at elucidating the more fine-grained regulatory anatomy underlying the tanning response.