RESUMO
Primary skin fibroblast cultures were grown from forearm pinch skin biopsies obtained from 24 patients with Duchenne muscular dystrophy (DMD) and ten normal controls matched for sex and age. The first subcultures were grown for 7 days and incubated with L-(3H)-proline for 24 hours. Intracellular collagen incorporation was significantly decreased (2.2 X) and extracellular collagen incorporation significantly increased (1.8 X) in fibroblast cultures from patients with DMD by both collagenase assay and polyacrylamide gel electrophoresis. The synthesis of noncollagen proteins showed low values from the DMD fibroblast cultures. The alterations in synthesis and secretion of collagen and noncollagen proteins were characteristic only for the log phase of DMD fibroblasts.
Assuntos
Colágeno/biossíntese , Fibroblastos/metabolismo , Distrofias Musculares/metabolismo , Biossíntese de Proteínas , Células Cultivadas , Colágeno/metabolismo , Meios de Cultura , Eletroforese em Gel de Poliacrilamida , Feminino , Humanos , Masculino , Proteínas Musculares/biossíntese , Proteínas Musculares/metabolismo , Distrofias Musculares/fisiopatologia , Prolina/metabolismo , Proteínas/metabolismoRESUMO
Muscle samples for cultures were obtained from the quadriceps by open biopsy under local anesthesia in five patients with early stage of Duchenne muscular dystrophy (DMD) and 10 controls. Primary cultures were grown in Eagle's Minimum Essential Medium (MEM) with 20 per cent fetal calf serum. After 4 weeks, cells were trypsinized, counted, subcultured for 5 days in MEM with 5 per cent horse serum and finally incubated for 4 h with (3H) leucine. Ttal protein synthesis showed a significant decrease (half of control values) only in muscle cultures from patients with DMD. Addition of calclium chloride alone or with A23187 ionophore normalized this defect in protein synthesis. By contrast, myosin heavy chain synthesis was measured and found normal in all paitents.