Background: The most common disorders of the thyroid gland are hyperthyroidism and hypothyroidism. Both have been linked to cell damage.
Aim of Work: This study was designed to evaluate the effect of melatonin administration on the testis of both hyperthyroidic and hypothyroidic adult male albino rats models.
Materials and Methods: Fifty adult male albino rats were used in this study and divided into five groups; ten rats each. Control group (G1) was given distilled water. Hyperthyroidic group (G2) was given thyroxin (0.2 mg/kg b.w). Hyperthyroidic+melatonin group (G3) was given thyroxin (0.2 mg/kg b.w) and melatonin (2.5 mg / kg b.w). Hypothyroidic group (G4) was given carbimazole (1.35 mg/kg b.w). Hypothyroidic+melatonin group (G5) was given carbimazole (1.35 mg/kg b.w) and melatonin (2.5 mg / kg b.w). All the treatments were given orally for 15 days. At the end of the study, the animals of all groups were sacrificed and their testes were rapidly dissected out. The testicular mass was calculated. Testicular specimens of each group were processed for light and electron microscopic studies.
Results: The testicular mass was significantly decreased in both hyperthyroidic group (G2) and hypothyroidic group (G4) when compared with the control. Light and electron microscopy of the hyperthyroidic group (G2) and hypothyroidic group (G4) showed seminiferous tubular germ cells disorganization with increased intercellular spaces, necrosis and cellular damage. Melatonin supplementation to rats given Thyroxin (G3) improved the testicular mass and the cell damage. On the contrary, melatonin supplementation to rats given carbimazole (G5) did not show any improvement on both morphometrical and histological levels.
Conclusion: It was concluded that simultaneous melatonin administration effectively depresses the negative effects of hyperthyroidism but not hypothyroidism on the adult male rat testis.