THE EFFECT OF HIGH DOSE TESTOSTERONE ENANTHATE ADMINISTRATION ON HISTOMORPHOLOGY OF THYROID GLAND IN RATS

Testosterone enanthate (TE), due to its anabolic effects, is widely used by athletes as a stimulating drug for the muscle strength. Previous studies showed that high doses of TE may have some effects on the secretion of metabolic hormones. In this study we evaluated the effect (s) of high doses of TE administration on histomorphology of the thyroid gland. For this purpose, forty male Charles River rats (210-220g) were divided into five groups of 8: group I, non-treated control group, group II rats were gonadectomized and received TE (5mg/100g b.w, i.p, weekly), group III was sham- operated non-gonadectomized rats receiving the same dose of TE as group II. Group IV was gonadectomized rats, which received vehicle (olive oil), and group V was sham-operated non-gonadectomized rats receiving vehicle. In each group, blood samples were taken from rats after 60 days and the thyroid glands were removed and prepared for histomorphological studies. The serum levels of testosterone were measured by ELISA technique. The results show that diameter of thyroid gland follicles of the groups that received a high dose of TE, was increased significantly (P<0.05) compared to those of the control group. These results suggest that testosterone, at high concentration, stimulates proliferation of follicular cells of thyroid gland, however, it also attenuates their functional activities.