Ultrastructural aspects of the transformation of muscle fibre type by long term stimulation: changes in Z discs and mitochondria.

AUTOR(ES)

Salmons, S

RESUMO

The criteria which serve to distinguish the slow from the fast type of mammalian skeletal muscle include differences at the ultrastructural level, in particular differences in Z disc morphology and mitochondrial content. If a fast muscle is subjected to sustained low frequency impulse activity similar to that normally received by a slow muscle, its physiological and biochemical properties become indistinguishable from those of a slow muscle. In the present study we have examined the fine structure of fast muscles stimulated in this way. The thickness of Z discs was significantly greater than that of control fast muscles and indistinguishable from that of slow muscles. Mitochondrial profiles, seen only infrequently in control fast muscles, were abundant in their stimulated counterparts. The regulatory influence of impulse activity on the differentiation of skeletal muscle thus extends to some of its most characteristic ultrastructural features.

Documentos Relacionados

• Zidovudine induces molecular, biochemical, and ultrastructural changes in rat skeletal muscle mitochondria.
• AZT treatment induces molecular and ultrastructural oxidative damage to muscle mitochondria. Prevention by antioxidant vitamins.
• Fibre type changes in striated muscle of alcoholics
• Muscle fibre type changes in hypothyroid myopathy.
• Volume changes in liver mitochondria.