RESUMO
Myogenic satellite cells were isolated from the turkey pectoralis major (PM), a muscle composed largely of white fibers, and the biceps femoris (BF), a muscle composed largely of red fibers, and their properties were compared in culture. Satellite cells derived from the PM and BF muscles exhibited differences in metabolic parameters, growth factor receptor characteristics, and mitogenic responses. PM satellite cells exhibited greater responsiveness to platelet-derived growth factor (PDGF), and the PDGF receptor on these cells had a higher affinity toward ligand compared to BF cells (P < 0.05). Protein synthesis, protein degradation, and glucose uptake rates were higher in BF satellite cell cultures (P < 0.05), correlating with previously reported in vivo measurements using red and white muscle fibers.
Assuntos
Substâncias de Crescimento/metabolismo , Fibras Musculares de Contração Rápida/metabolismo , Músculo Esquelético/metabolismo , Receptores de Fatores de Crescimento/metabolismo , Animais , Ligação Competitiva , Células Cultivadas , Relação Dose-Resposta a Droga , Fatores de Crescimento de Fibroblastos/análise , Fatores de Crescimento de Fibroblastos/metabolismo , Substâncias de Crescimento/análise , Fator de Crescimento Insulin-Like I/análise , Fator de Crescimento Insulin-Like I/metabolismo , Radioisótopos do Iodo , Masculino , Fibras Musculares de Contração Rápida/citologia , Músculo Esquelético/citologia , Músculos Peitorais/citologia , Músculos Peitorais/metabolismo , Fator de Crescimento Derivado de Plaquetas/análise , Fator de Crescimento Derivado de Plaquetas/metabolismo , Receptor IGF Tipo 1/metabolismo , Receptores de Fatores de Crescimento de Fibroblastos/metabolismo , Receptores do Fator de Crescimento Derivado de Plaquetas/metabolismo , PerusRESUMO
The role of platelet-derived growth factor (PDGF) isoforms in the proliferation of turkey skeletal muscle cells was examined using turkey myogenic cells. To compare the effects of PDGF during different developmental stages, postnatal myogenic satellite cell and embryonic myoblast cultures were developed for in vitro comparisons. Satellite cell cultures from turkeys selected and unselected for skeletal muscle accretion rates were also established to compare the role of PDGF in turkeys with different genetic origins. The results demonstrated that the BB and AB isoforms of PDGF enhanced satellite cell and embryonic myoblast proliferation, while the AA isoform had no effect. Satellite cells and embryonic myoblasts were more responsive to the BB isoform than to the AB isoform. Competitive binding assays demonstrated that there were no differences between PDGF receptor affinities or receptor numbers on either embryonic myoblasts and satellite cells or satellite cells derived from selected and unselected turkeys. The results suggest that PDGF may be an important mitogenic factor in turkey skeletal muscle development.
Assuntos
Mitógenos/farmacologia , Desenvolvimento Muscular , Músculo Esquelético/crescimento & desenvolvimento , Fator de Crescimento Derivado de Plaquetas/farmacologia , Perus/fisiologia , Animais , Becaplermina , Separação Celular , Relação Dose-Resposta a Droga , Interações Medicamentosas , Fatores de Crescimento de Fibroblastos/farmacologia , Músculo Esquelético/citologia , Músculo Esquelético/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-sis , Receptores do Fator de Crescimento Derivado de Plaquetas/análise , Receptores do Fator de Crescimento Derivado de Plaquetas/metabolismoRESUMO
Protein synthesis, protein degradation, and glucose uptake were compared in clonal-derived turkey myogenic satellite cells (clone D5-SC) and embryonic myoblasts (EM) and between satellite cell cultures from Nicholas (DN) and Merriam's (WM) turkeys. Protein synthesis rates were higher and degradation rates were lower in myotube cultures of D5-SC compared with EM (P < or = 0.05). Protein synthesis and degradation rates did not differ between cultures of DN and WM (P > or = 0.05). Glucose transport rates were significantly higher in EM than D5-SC cultures and did not differ between DN and WM cultures. Insulin-like growth factors and insulin stimulated protein synthesis, decreased protein degradation, and increased glucose uptake in all cell lines.