RESUMO
Biochemical analysis of skin samples revealed that the content of type III collagen was greatly reduced in several subjects with joint hypermobility, stretchability and bruisability of skin. When cultured dermal fibroblasts were found to secrete decreased amounts of type III procollagen into medium (about 30-45% the normal amount) and serum type III procollagen aminopropeptide levels were significantly lower than normal values (P less than 0.001). The abnormalities in type III procollagen are in keeping with Ehlers-Danlos type IV although the clinical findings in our patients are not normally associated with this disorder. The results illustrate the clinical heterogeneity of Ehlers-Danlos type IV and the importance of biochemical analysis, such as determination of type III procollagen aminopropeptide levels, to check type III collagen metabolism especially if there is no family history and if correct diagnosis is not reliable by clinical examination alone.
Assuntos
Colágeno/deficiência , Síndrome de Ehlers-Danlos/metabolismo , Fragmentos de Peptídeos/sangue , Pró-Colágeno/sangue , Criança , Pré-Escolar , Colágeno/metabolismo , Feminino , Fibroblastos/metabolismo , Humanos , Masculino , Pele/metabolismoRESUMO
The mechanism of action of the total triterpenoid fraction extracted from Centella Asiatica (TTFCA) was evaluated using human skin fibroblasts cultures as the experimental system. In particular its influence on the biosynthesis of collagen, fibronectin and proteoglycans was considered. The presence of TTFCA (25 micrograms/ml) does not seem to affect cell proliferation, total protein synthesis or the biosynthesis of proteoglycans in a significant way. A statistically important increase was observed in the percentage of collagen and, as revealed by immunofluorescence measurements, in cell layer fibronectin. This effect on collagen and fibronectin may help to explain the action of TTFCA in promoting wound healing, and suggests an interesting working hypothesis for its action on basal endothelia.
