RESUMEN
Using light microscopy, morphometry and immunohistochemistry, the epidermis of 72 male and female rats was examined 1 day and 1 month after the completion of daily cutaneous applications of vitamin D3-containing composition lasting for two weeks. It was found that vitamin D3 causes a statistically significant reduction in the thickness of interfollicular epidermis and in the number of Ki-67 positive keratinocytes. The identified effects persisted for 1 month after the last application of the preparation. Modifying influence of vitamin D3 on the morphogenetic processes in the epidermis, which were manifested, in particular, by a decreased proliferative activity of keratinocytes, is discussed in the light of the data on the possibility of the formation of its active metabolite--calcitriol--directly in the skin.
Asunto(s)
Proliferación Celular/efectos de los fármacos , Epidermis/efectos de los fármacos , Queratinocitos/efectos de los fármacos , Vitamina D/farmacología , Administración Cutánea , Animales , Células Epidérmicas , Femenino , Queratinocitos/química , Queratinocitos/fisiología , Antígeno Ki-67/análisis , Masculino , Ratas , Vitamina D/administración & dosificaciónRESUMEN
Immunocytochemical methods were used to study the population of keratinocytes of interfollicular epidermis in rats under the conditions of morphogenesis, experimentally modified by an application of 13-cis-retinoic acid (0.025% and 0.05% solutions for two weeks). The treatment resulted in the increase of the number of PCNA+ and Ki-67+ nuclei in the epidermis and of the thickness of epithelial cell layer, not involved in cytokeratin 10 synthesis.
Asunto(s)
Epidermis/efectos de los fármacos , Isotretinoína/farmacología , Queratinocitos/efectos de los fármacos , Morfogénesis , Animales , Epidermis/química , Epidermis/crecimiento & desarrollo , Inmunohistoquímica , Queratinocitos/química , Antígeno Ki-67/análisis , Masculino , Antígeno Nuclear de Célula en Proliferación/análisis , Ratas , Ratas WistarRESUMEN
Changes of the histological structure of rat's skin were studied two weeks following the daily applications of native birch tar and of purified birch tar, devoid of the components that could be potentially dangerous for humans. The morphometric investigations were performed with the use of computer technologies on the apparatus-programme complex (DiaMorph, Russia). It has been established that the main morphological manifestations of specific dermatotropic activity of birch tar in the present experiment included: epidermal hypertrophy, hyperkeratosis, stimulation of the activity of all dermal cellular elements, intensification of blood supply, reduction of sebaceous glands. Analysis of morphological findings indicates the bioequivalence of the native and purified birch tar in terms of its specific dermatotropic activity.