Effects of neurotomy on human skeletal muscle ultrastructure / Efectos de la neurotomia sobre la ultraestructura del musculo esquelético humano

Effects of neurotomy on human skeletal muscle ultrastucture were studied in biopsies from denervated abdominal muscles. After 35 days of denervation the alterations included fiber atrophy which varied from slight to total, swelling and disalignment of sarcotubular system, nuclear changes, mitochondrial abnormalities, and lysosomal proliferation. Capillaries were normal and no cell infiltration was evident. Cases studied several months after neurotomy showed signs of reinnervation with a partial recovery of normal structure. The differences between the histopathological pictures caused by neurotomy and by degenerative diseases which produce neurogenic atrophy are discussed. The restorative capacity of human skeletal muscle after spontaneous reinnervation is also studied. Key words: Neurotomy, Denervation, Reinnervation, Ultrastructure, Muscle pathology, Neurogenic atrophy

Ultrastructural fiber typing of human abdominal muscles obliquus internus and obliquus externus

Con el objeto de clasificar los tipos de fibras presentes, se estudiaron al microscopio electrónico biopsias de los músculos abdominales oblicuo interno (OI) y oblicuo externo (OE), que habían sido obtenidas durante lumbotomías hechas por motivos urológicos. Usando criterios ultraestructurales se clasificaron la s fibras del OI como Tipo I (18%), Tipo IIa (62%) y Tupo IIb (20%). En el OE los porcentajes fueron: Tipo I (24%), Tipo IIa (53%) y Tipo IIb (23%). Se discuten las relaciones existentes entre estos resultados y otros obtenidos por métodos histoquímicos