RESUMO
Histopathological interpretation of semimembranosus muscle samples from an adult Warmblood mare with clinical signs suggestive of exertional rhabdomyolysis and intermittent mild elevations in muscle enzyme activities revealed abundant sarcoplasmic vacuoles in all fibre-types containing fine, apparently proteinaceous debris. Vacuolar contents stained lightly with PAS, but did not appear to contain amylopectate, lipid or acid phosphatase and their periphery was unstained with dystrophin immunohistochemistry. Electron microscopy revealed that vacuoles were not membrane bound. No vacuoles were detected in muscle samples evaluated at post mortem following 4 months of rest. To our knowledge, this is the first report of a presumed primary vacuolar myopathy in a horse.
Assuntos
Doenças dos Cavalos/patologia , Doenças por Armazenamento dos Lisossomos/veterinária , Doenças Musculares/veterinária , Envelhecimento , Animais , Distrofina/metabolismo , Feminino , Doenças dos Cavalos/metabolismo , Cavalos , Imuno-Histoquímica , Doenças por Armazenamento dos Lisossomos/metabolismo , Doenças por Armazenamento dos Lisossomos/patologia , Microscopia Eletrônica/métodos , Doenças Musculares/metabolismo , Doenças Musculares/patologiaRESUMO
When rats were treated with chlorphentermine, a cationic amphiphilic drug, a phospholipid storage disorder developed in alveolar macrophages, the severity of which was directly proportional to the duration of treatment over a 4-week period. Concomitantly, a progressively greater percentage of the cells became multinucleated such that, after 4 weeks of drug treatment, 18 per cent of the cells contained more than one nucleus. Greater than 99 per cent of the macrophages from control rats had on nucleus per cell. Associated with the multinucleation was an increase in the DNA, RNA, and protein content of the macrophages and increases in the RNA to DNA and protein to RNA ratios relative to cells from untreated rats. Centrifugal elutriation was employed as a means to study the multinucleation as a function of increasing cell size. At each of the 4 weekly intervals studied, the percentage of cells with two or more nuclei increased as the cells became larger. An increase in multinucleation was also found in cells of any given size range as the time of treatment increased. Possible mechanisms responsible for the multinucleation phenomenon are discussed.
