Myocardial ultrastructural alterations in ducklings with XXXX -induced cardiotoxicosis.

@entity4186 @entity227 @entity296 @entity39 @entity16 @entity3044 @entity1370
Fifty-two, 8-week-old, male White Pekin ducklings ( @entity4186 domesticus) were allotted into control (n = 7) and @entity3044 -injected groups (n = 45). One control @entity4186 and 5 to 7 @entity3044 -injected (200 mg/kg of body weight) ducklings were euthanatized at postinjection hours (PIH) 1, 12, and 24 and at @entity227 ( @entity227 ) 2, 4, 7, and 14. The left ventricular myocardium was examined, using electron microscopy. The earliest ultrastructural alteration in damaged myocytes was myofibrillar lysis at PIH 12. At PIH 24, affected myocytes had @entity39 with mineralization of mitochondria. By @entity227 2, macrophages had invaded into areas of @entity296 , mineralization was prominent in myocyte mitochondria, and dedifferentiated myocytes with reduced numbers of myofibrils, increased numbers of polysomes, large nuclei, and prominent nucleoli were first observed. The primary myocardial finding at @entity227 4, 7, and 14 was 2 populations of sublethally damaged myocytes. One population of injured myocytes had numerous polysomes in the sarcoplasm and large nuclei with prominent nucleoli, indicating attempts at repair of @entity16 . The 2nd population of myocytes with myofibrillar lysis did not have morphologic evidence of myofibrillar repair. Therefore, the sequential ultrastructural alterations of damage and repair induced by @entity3044 in the duckling myocardium provided model for comparative studies of @entity1370 .
