Medical Science Research, cilt.27, sa.12, ss.795-799, 1999 (SCI-Expanded)
The purpose of this study was to investigate the effect of long-term high dietary selenium intake on myocardial ultrastructure in rabbits. One-month-old male and female rabbits were fed with either selenium (Se) excess (4.2 mg Se/kg diet) or a selenium adequate (0.23 mg Se/kg diet) diet for 3 months. Myocardial tissue was processed for transmission electron microscopy and light microscopy. Degenerative changes indicating disintegration of internal structure were observed in the myocytes of the heart muscle of Se-supplemented animals, while the myocardium of animals fed a Se-adequate diet was normal ultrastructurally. Degenerative changes were mainly disruption of myofibrils, marked cavitation of space and irregular sarcomeres. There were distortions in the region of intercalated discs, mitochondrial alterations with a different distribution through the myocardial fibres and poorly developed and disorganized cristae. The excess Se in the diet caused marked myocardial alterations, particularly in the mitochondrial matrix of myocytes. Changes in the mitochondria were considered to be evidence of irreversible cell injury induced by long-term high dietary Se intake.