Furazolidone-induced congestive cardiomyopathy in ducklings: myocardial ultrastructural alterations.
Newly hatched male White Pekin ducklings were fed furazolidone (FZ) at dosage of 750 mg/kg of feed for 4 weeks. Selected ducklings with advanced lesions of FZ-induced congestive cardiomyopathy were used for ultrastructural study of the myocardial alterations. Semithin sections of plastic-embedded blocks of myocardium from these dilated hearts revealed diffuse myocytolysis, characterized by pale sarcoplasm and lack of cross-striations in affected myocytes. Evidence of myocardial necrosis, inflammation, or fibrosis was not observed. Ultrastructural study revealed that the principal alteration in cardiac muscle cells was diffuse myofibrillar lysis. The sarcoplasm of affected myocytes had scattered masses of free thick and thin myofilaments, clumps of Z-band material, and accumulations of cytoskeletal filaments. Numerous polyribosomes were present in the areas of lysis of contractile material, as were other normal-appearing organelles. Myofibrillar lysis may have resulted from FZ-induced decreased synthesis, increased degradation, or disaggregation of contractile proteins. Ducklings with FZ-induced congestive cardiomyopathy offer an attractive model for studies of the biochemical and ultrastructural alterations of myofibrillar lysis and drug-induced cardiac failure.
D000818:Animals; D009202:Cardiomyopathies / Q000139:chemically induced / Q000473:pathology / Q000662:veterinary*; D004372:Ducks; D005664:Furazolidone / Q000633:toxicity*; D006333:Heart Failure / Q000139:chemically induced / Q000473:pathology / Q000662:veterinary*; D008297:Male; D009206:Myocardium / Q000378:metabolism / Q000648:ultrastructure*; D009210:Myofibrils / Q000648:ultrastructure; D011201:Poultry Diseases / Q000139:chemically induced / Q000473:pathology*; D011506:Proteins / Q000378:metabolism
D011506:Proteins; D005664:Furazolidone