EFFECT OF ANTIINSULIN-LIKE GROWTH-FACTOR-1 ON EPIDERMAL PROLIFERATIONOF HUMAN SKIN TRANSPLANTED ONTO NUDE-MICE TREATED WITH GROWTH-HORMONE

Recently it has been demonstrated that long-term administration of GH leads to increase of skin thickness. The aim of the present study was to determine whether this effect of GH is mediated by insulin growth f actor 1 (IGF-1), which enhances epidermal proliferation. In order to a ddress this question, human split-thickness grafts obtained from aged skin were grafted onto nude mice. One group of mice was treated system ically with GH, whereas a second group was treated with intradermal gr aft injections of anti-IGF-1 in addition to GH. A third group received distilled water and served as a control group. Histological and autor adiographic analyses were performed before and after engraftment. The GH-treated mice showed a significant increase in epidermal proliferati on measured by epidermal thickness (analysis of variance with repeated measurements, P < 0.01) and labeled index (analysis of variance, P < 0.01) as compared to the control group. The intradermal injections of anti-IGF-1 reduced significantly the proliferative stimulatory effect of GH (P < 0.01). The present study emphasizes the role of IGF-1 in th e increased skin thickness observed after GH administration and provid es a useful model for determining the effect of various compounds, inc luding GH, on human skin.