ABSTRACT
Extracellular matrix and costamere proteins transmit the concentric, isometric, and eccentric forces produced by active muscle contraction. The expression of these proteins after application of passive tension stimuli to muscle remains unknown. This study investigated the expression of laminin and dystrophin in the soleus muscle of rats immobilized with the right ankle in plantar flexion for 10 days and subsequent remobilization, either by isolated free movement in a cage or associated with passive stretching for up to 10 days. The intensity of the macrophage response was also evaluated. One hundred and twenty-eight female Wistar rats were divided into 8 groups: free for 10 days; immobilized for 10 days; immobilized/free for 1, 3, or 10 days; or immobilized/stretched/free for 1, 3, or 10 days. After the experimental procedures, muscle tissue was processed for immunofluorescence (dystrophin/laminin/CD68) and Western blot analysis (dystrophin/laminin). Immobilization increased the expression of dystrophin and laminin but did not alter the number of macrophages in the muscle. In the stretched muscle groups, there was an increase in dystrophin and the number of macrophages after 3 days compared with the other groups; dystrophin showed a discontinuous labeling pattern, and laminin was found in the intracellular space. The amount of laminin was increased in the muscles treated by immobilization followed by free movement for 10 days. In the initial stages of postimmobilization (1 and 3 days), an exacerbated macrophage response and an increase of dystrophin suggested that the therapeutic stretching technique induced additional stress in the muscle fibers and costameres.
Subject(s)
Animals , Female , Dystrophin/metabolism , Immobilization/methods , Laminin/metabolism , Macrophages/metabolism , Muscle Stretching Exercises/methods , Muscle, Skeletal/physiology , Blotting, Western , Dystrophin/isolation & purification , Extracellular Matrix/metabolism , Fluorescent Antibody Technique , Intracellular Space/metabolism , Laminin/isolation & purification , Mechanotransduction, Cellular/physiology , Muscle, Skeletal/injuries , Rats, WistarABSTRACT
Serum P-III-P and laminim levels were measured in asymptomatic alcoholics during detoxication treatment. Liver biopsies were obtained, in order to detect liver damage, which was graded with a numeric score, considering values over 6 as severe damage. Serum fibrogenesis markers were also measured in a group of decompensated alcoholic cirrhotics. P-III-P levels were significantly higher in cirrhotic patients compared to alcoholics with or without liver damage and to normal controls. Laminin was not different between groups. P-III-P did not correlate with histological score in asymptomatic patients. In this study P-III-P and P1 laminin were not usefull discriminators of severe liver damage among asymptomatic alcoholics; their levels were found to rises significantly only when liver disease has become clinically evident
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Alcoholism/complications , Liver Cirrhosis, Alcoholic/pathology , Biomarkers/analysis , Laminin/isolation & purification , Procollagen N-EndopeptidaseABSTRACT
Laminina-1 liga-se especificamente a formas tripomastigotas de Trypanosoma cruzi e anticorpos gerados contra laminina-1 inibem entre 62-75 por cento a interiorizaçäo do T. cruzi em células LLC-MK2, sugerindo a participaçäo desta glicoproteína no processo de adesäo/interiorizaçäo do parasita em células näo-fagocíticas profissionais. Uma glicoproteína de peso molecular aparente de 85 kDa, denominada LBG (Laminin Binding Glycoprotein), foi identificada em formas tripomastigotas como o principal ligante de laminina-1 no Trypanosoma cruzi, sendo a interaçäo laminina-LBG independente dos carboidratos de ambas as moléculas e mediada preferencialmente pelo fragmento E8 da laminina-1. A LBG é reconhecida por um anticorpo monoclonal (H1A10), previamente descrito na literatura...