RESUMEN
Purpose of the investigation was to examine structural rearrangements in the cortical cytoskeleton as a result of changes in external mechanic conditions. Objects of the investigation were Wistar rat's m. soleus fibers and left ventricle hystiocytes. Suspension for 6, 12, 18, 24 and 72 hours was performed according to the Ilyin-Novikov procedure modified by Morey-Holton. Cell stiffness, non-muscle actin and actin-binding proteins in the protein membrane and cytoplasmic fractions, and respective gene expression were evaluated. In addition, corticosterone levels were measured in blood serum. After 6 hours of suspension, actin-binding proteins went down in the membrane fraction, i.e. alpha-actinin-1 decreased in hystiocytes and alpha-actinin-4 in m. soleus fibers. On the contrary, their content in the cytoplasmatic fraction increased. Expression of genes coding beta- and gamma-actin, alpha-actinin-1 and alpha-actinin-4 in m. soleus fibers showed a decrease. However, the apha-actinin-1 gene regained its baseline expression rate in 72 hours. Following 18 to 24 hours of suspension, expression of the beta-actin and alpha-actinin-4 genes in hystiocytes grew in comparison with baseline values, while expression of alpha-actinin-1 gene decreased. After 12 hours of suspension, beta- and gamma-actin levels were reduced in membrane proteins and increased in cytoplasmatic proteins in hystiocytes and m. soleus fibers. Stiffness showed a decline in each type of cell. Further into suspension, membrane proteins of hystiocytes increased levels of non-muscle actin and actin-binding proteins, and stiffness of these cells. Levels of these proteins decreased in m. soleus fibers, as also did cell stiffness. Serum corticosterone hardly altered but was slightly increased after 6 hours of suspension.
Asunto(s)
Citoesqueleto/metabolismo , Células Dendríticas/metabolismo , Ventrículos Cardíacos/metabolismo , Macrófagos/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Actinina/genética , Actinina/metabolismo , Actinas/genética , Actinas/metabolismo , Animales , Membrana Celular/metabolismo , Corticosterona/sangre , Citoplasma/metabolismo , Citoesqueleto/genética , Citoesqueleto/ultraestructura , Células Dendríticas/ultraestructura , Expresión Génica , Ventrículos Cardíacos/ultraestructura , Suspensión Trasera , Macrófagos/ultraestructura , Fibras Musculares Esqueléticas/ultraestructura , Músculo Esquelético/metabolismo , Músculo Esquelético/ultraestructura , Ratas , Ratas WistarRESUMEN
The aim of the work was to study the parameters of fibers cell respiration and desmin content in Wistar rat soleus muscle after 1, 3, 7 and 14 days of gravitational unloading. Gravitational unloading was simulated by antiorthostatic hindlimb suspension. The parameters of cell respiration were determined using the polarography, and desmin content was assessed by means of Western blotting. The results showed that the intensity of cell respiration is reduced after three days of gravitational unloading, reaches a minimum level after seven days and slightly increases by the fourteenth day of hindlimb unloading, as well as the content of desmin, which, however, to the fourteenth day returns to the control level. Taking into account that mitochondrial function depends on the state of cytoskeleton the data allow us to assume that early reduction of the intensity of cell respiration under unloading could be caused by degradation of the protein desmin that determines intracellular localization of mitochondria.
Asunto(s)
Desmina/análisis , Gravitación , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/metabolismo , Animales , Respiración de la Célula , Suspensión Trasera , Masculino , Mitocondrias Musculares/metabolismo , Músculo Esquelético/química , Ratas , Ratas Wistar , Factores de TiempoRESUMEN
Cell breathing and relative desmin content were investigated in m. soleus fibers of rats after 3 and 7 days of recovery from 14-day suspension according to the Morey - Holton modification of the Ilyin - Novikov procedure. The cell breathing parameters were determined with the help of polarography; desmin content was measured using the western-blot technique. The results evidence that cell breathing intensity subsided during 14 days of gravitational unloading, reached minimum after 3 days of recovery and regained baseline values after 7 days of recovery. Post suspension desmin content did not differ from control values, made a significant drop in 3 days and returned to baseline values in 7 days of recovery. These data suggest an interdependence between cell breathing and desmin content in m. soleus fibers of rats as during gravitation unloading, so in the period of recovery.