title: Muscle damage and autoantibody fixation in an experimental model of autoimmune myopathy.
abstract: An experimental model of autoimmune myopathy was designed using parental antigens (muscle mitochondrial fraction) in F1 hybrid rats (male Wistar x female Sprague-Dawley). The immune response was modulated by spleen fragment transplant from either Wistar (W) or F1. Antibody fixation and inflammatory reaction were studied in Extensor digitorum longus and soleus muscles. Immunization without spleen transplant resulted in antibody fixation mainly in capillaries and incompletely around muscle fibers; whorled fibers were found in 1/3 of F1 rats immunized with antigen from W rats. Spleen transplants from Sprague Dawley (SD) rats were usually accepted by F1; in some animals, antibodies surrounded completely muscle fibers and the percentage of animals showing soleus muscle lesions was increased. Spleen transplants from non immunized F1 were usually rejected by immunized F1; antibody reaction was found inside fibers of most of the rats, muscle damage was present in 40% of the animals immunized with W, but absent in those immunized with SD antigen. In conclusion, this model can be used to study immunological responses to alloantigens (parental to F1). Spleen fragment transplant modulates the immune response. There was discrepancy between antibody fixation and muscle damage. The immunological response was different according to muscle fiber type composition and/or microcirculatory characteristics.
authors.affiliation: Institute of Experimental Medicine, Faculty of Medicine, Central University of Venezuela, Apdo. 50587, Caracas 1050-A, Venezuela.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Losada
authors.forename: Ana Marina
authors.initials: AM
authors.lastname: Wangüemert
authors.forename: Sonia H
authors.initials: SH
authors.lastname: Torres
authors.forename: Noelina
authors.initials: N
authors.lastname: Hernández
authors.forename: Miriam
authors.initials: M
authors.lastname: Rivas
authors.forename: Carlos
authors.initials: C
authors.lastname: Bravo
authors.forename: María Magdalena
authors.initials: MM
authors.lastname: Pulido
mesh_terms: D000818:Animals; D001323:Autoantibodies / Q000276:immunology*; D001327:Autoimmune Diseases / Q000276:immunology*; D005260:Female; D006614:Hindlimb; D008297:Male; D008931:Mitochondria, Muscle / Q000276:immunology; D018485:Muscle Fibers, Skeletal / Q000276:immunology; D018482:Muscle, Skeletal / Q000276:immunology* / Q000473:pathology*; D009135:Muscular Diseases / Q000276:immunology* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D013154:Spleen / Q000637:transplantation
chemical_list: D001323:Autoantibodies