Hair Growth on Nude Mice Due to Cyclosporin A

Abstract

One of the most common dermatological side effects of cyclosporin A (CsA) is dose-dependent hypertrichosis. Similar hair growth was noted in nude mice in an attempt to increase the acceptance of human xenografts with CsA in the T-cell-deficient congenitally athymic nude (nu/nu) mice. The aim of the present study was to further investigate the stimulation of hair growth on nude mice not only by oral administration of CsA but also by topical and subcutaneous administration of CsA. Young BALB/c female nude mice were treated for 3 or 4 weeks with topical, oral, or subcutaneous applications of CsA dissolved in olive oil at various doses. The hair of CsA-treated mice appeared to grow from 7 days after the treatment, even at low doses. Induced hair growth was dose-dependent and became clearly obvious 3 weeks after the treatment. The stimulation of hair growth was not restricted to the site of topical application. The distribution of the new hair depended on the natural pattern of hair growth in the mice. However, there was no hair growth in the control mice which were given only olive oil. Histological examination revealed that there were no differences in the structures of skin and hair between the control and the CsA-treated mice. Furthermore, the number of hair follicles did not remarkably increase after CsA treatment. The hair growth in the CsA-treated mice stopped after cessation of the treatment and returned to the level of the control mice on day 14 after the end of the treatment. Subsequent retreatment with CsA resulted in further regrowth of the hair.(ABSTRACT TRUNCATED AT 250 WORDS)

Cyclosporin A reduces matrix metalloproteinases and collagen expression in dermal fibroblasts from regenerative FOXN1 deficient (nude) mice

“…In vivo studies by Watanabe et al , showed that CsA treated FOXN1 deficient (nude) mice overcome some aspects of FOXN1 deficiency, that is, they displayed hair re-growth [17]. In a follow up study they showed that this phenomenon may involve PKC, whose high activity in nude skin is suppressed by CsA treatment [18].…”

Cyclosporin A-induced hair growth in mice is associated with inhibition of calcineurin-dependent activation of NFAT in follicular keratinocytes

“…CsA has been also previously shown to induce hair growth both in nude (48) and normal mice (31,34). Our experimental data support these reports.…”

In vivohair growth-stimulating effect of medicinal plant extract on BALB/c nude mice

“…Skin specimens of the CZ-treated mice were also found to have abundant BrdU-positive keratinocytes in their hair bulbs and outer root sheaths. One hypothesis is that temporary keratinization in the HF gives strength to hair shafts that rise above the skin surface (Watanabe et al, 1991). Moreover, in this study we have closely observed two generations of hair growth, as well as macroscopic analysis of hair growth parameters that included changing patterns of nude mice hair growth, area of hair coverage, and length of hair shaft.…”