Morphologic Alterations Resulting from Denervation of the Diaphragm in Rats Alteraciones Morfol車gicas Resultantes de la Denervaci車n del Diafragma en Ratas

作者：M M Torrejais; J C Soares; S M M Matheus; L A D Francia Farje

来源：International Journal of Morphology, 2012.

• Diafragma
• Fibra muscular
• Denervacion
• Rata
• Diaphragm
• Muscle fiber
• Denervation
• Rat

The morphological alterations that occur in the muscle fibers of denervated rat diaphragms were studied. Fifteen adult male albino rats (Rattus norvegicus) with a mean weight of 200 g and about 60 days of age were used. Chronically denervated diaphragms were obtained and the animals were sacrificed after 4, 8 and 12 weeks of denervation. The left antimere of the diaphragm was denervated by sectioning of the phrenic nerve and the right antimere served as control. Each antimere was divided into two fragments, which were used for histological (H.E.) and histoenzymological (NADH-TR and myofibrillar ATPase). After 4 weeks, denervated muscle fibers showed important light microscopic alterations: atrophy with angular profiles in cross-sections, cytoplasm containing vacuoles, enlarged interstitial space with increased connective tissue, cellular infiltration, and muscle fibers without defined contours. The most marked alterations being observed for type IIb and IIa fibers. Eight and 12 weeks after denervation, the NADH-TR reaction showed that it was impossible to characterize the muscle fibers based on their metabolic profile. Fueron estudiadas las alteraciones morfol車gicas de las fibras musculares del diafragma denervado de ratas. Se utilizaron 15 ratas albinas (Rattus norvegicus) machos, adultos, con peso promedio de 200g y cerca de 60 d赤as de edad. Se denerv車 el diafragma y despu谷s de 4, 8 y 12 semanas los animales fueron sacrificados. El ant赤mero izquierdo del diafragma fue denervado por secci車n del nervio fr谷nico y el ant赤mero derecho fue utilizado como control. Cada ant赤mero fue dividido en fragmentos, utilizados para el estudio histol車gico (H-E), histoenzimol車gico (NADH-TR y ATPasa miofibrilar). Despu谷s de 4 semanas las fibras musculares denervadas presentaron alteraciones importantes en lamicroscop赤a de luz: atrofia con perfiles angulados en secciones transversales; citoplasma con vacuolas; aumento del espacio intersticial con aumento de tejido conjuntivo; infiltraci車n celular y fibras musculares sin contornos definidos, siendo las alteraciones m芍s marcadas en las fibras tipo IIb e IIa. Despu谷s de 8 y 12 semanas de denervaci車n la reacci車n para NADH-TR demuestra que es imposible caracterizar a las fibras musculares a trav谷s de su perfil metab車lico.