A morphometric study of myocardial mitochondria and myofibrils in turkey poults during development of furazolidone-induced cardiomyopathy.

Furazolidone (FZ) at a dose of 700 ppm was fed to turkey poults 2-5 weeks posthatching. At 3, 4, and 5 weeks of age, six poults each were sacrificed from control and FZ-fed groups. Samples of tissue from the outer free walls of the ventricles and the interventricular septum were removed and processed for electron microscopy. Volumetric density of mitochondria and myofibrils was determined by the point-counting technique. Significant reductions (p less than or equal to .05) in the volumetric density of mitochondria were observed at 5 weeks of age in the ventricular free walls of round-heart poults, and at 4 and 5 weeks of age in the interventricular septum. Significant reductions (p less than or equal to .05) in the volumetric density of myofibrils were noted at 4 weeks of age in the left ventricular free wall of FZ-fed normal poults and in the interventricular septum of round-heart poults. At 5 weeks of age, a significant increase (p less than or equal to .05) in myofibrils was observed in the left ventricular free wall of FZ-fed normal poults. Data confirms that the volumetric densities of mitochondria and myofibrils are significantly altered during development of FZ-induced hypertrophy.