EFFECT OF THE ANTIARRHYTHMIC "CORDARONE" ON THE THYROID GLAND
Nabil A. Hasan, Nagla M. Farag
Departments of Anatomy and Clinical Pathology, Faculty of Medicine Minia University
The present study was carried out to demonstrate the histological and histochemical changes that occur as a result of using the antiarrhythmic drug cordarone (amiodarone). Thirty-four adult male albino rats were used in this study. Rats were classified into the two groups: the control group (7 rats) and the treated group (27 rats). The treated group was divided into 3 subgroups according to the duration of cordarone administration (1 month, 3 months and 5 months). Blood samples were taken to measure serum T3, T4, and TSH levels. The thyroid gland was examined under light and electron microscopy. The results after 1 month of cordarone administration showed that there was decrease in the values of T3 & T4 and a non-significant increase in TSH values. Also there were minimal changes in the structures of the thyroid tissue. After 3 months of cordarone administration, there was a significant increase in the level of T3 & T4 and a significant decrease in TSH values. The changes in the structure of the thyroid tissue were marked at the end of this duration. After 5 months of cordarone administration, there was a highly significant increase in the values of T3 & T4 and a highly significant decrease in TSH values. There were many signs of apoptosis in the structures of the thyroid tissue as diminished apical microvilli, normal or distorted and indented nuclei, markedly dilated cisternae of rough endoplasmic reticulum (RER) distended follicles, follicular membrane disruption and damaged mitochondrial cisternae. In conclusion, cordarone produced histological and histochemical changes in the follicular cells of the thyroid gland. The changes were time related. The longer the period of drug administration the more the changes produced. Continuous monitoring of thyroid function must be done during administration of cordarone.