The pathomorphology of developing skeletal muscles of rabbits treated with glucocorticoids.

Autor: Jirmanová, Isa, Soukup, T., Zelená, Jiřina
Zdroj: Virchows Archiv B Cell Pathology; Dec1981, Vol. 38 Issue 1, p323-335, 13p
Abstrakt: Dexamethasone or hydrocortisone were applied daily to rabbits from the first to the ninth day after birth and the structure of skeletal muscles was studied with the aim of demonstrating changes induced by glucocorticoids. Muscle development was arrested following treatment with glucocorticoids and individual muscle fibres showed atrophy and degenerative changes. Nine days after treatment, the mean fibre diameter in the biceps femoris muscles was decreased to 6.16 ± 1.08 μm, as compared with the mean diameter 7.95 ± 1.28 μm in the same muscles of new-born rabbits and with 9.03±0.56 μm of 9-day-old control animals (x ± S.E.). The ultrastructure of muscle fibres of the biceps femoris was variously impaired after treatment, except for the largest fibre of each fascicle which usually remained unaffected. The changes induced by corticosteroids ranged from a slight reduction of myofibrillar content to severe myofibrillar deficiency, vacuolization, focal degeneration and necrosis. The differentiation of satellite myoblasts and myotubes was retarded after treatment and numerous satellite cells underwent degeneration. As the character and extent of structural changes induced in developing muscles by glucocorticoids resemble the pathomorphology of congenital myofibrillar hypoplasia of piglets, the possibility of a common pathogenesis in the two conditions is considered. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index