Histopathological changes in testicles and uterus of rats with hyperthyroidism and hypothyroidism

Abstract

PURPOSE: The aim of this article was to determine the features of pathomorphological changes in testicles and uterus of rats associated with thyroid hormone (TH) levels. MATERIAL AND METHODS: Experimental dysfunction of thyroid gland was induced in rats by daily administration of thyroxin in a dose of 50 μg/100 g (hyperthyroidism) and mercazolil in a dose of 5 μg/100g (hypothyroidism). Thyroid and sex hormone profiles were determined. Microscopy and morphometry of testicles in males and uterus in females were performed. The quantity of spermatids and spermatozoa as well as total number of spermatogenic cells was calculated. RESULTS: Hypothyroidism reduced TH concentrations in female rats and increased sex hormones while hyperthyroidism augmented TH and sex hormone levels. In hypothyroid male rats, a decreased TH and unchanged testosterone levels were found out while in hyperthyroid ones there were increased TH and decreased testosterone levels. There was a gender difference in terms of TH changes in hyperthyroidism, i.e. T3 and T4 elevation was more outlined in male than in female rats. The most significant histopathological changes were established in the uterus of hyperthyroid female rats and presented with signs of an acute vascular insufficiency, inflammation, hypertension and fibrosis. Hypothyroidism exerted a crucial effect on pathomorphological changes in rat testicles consisting in atrophy of spermatogenic epithelium, vascular insufficiency, hypertension and fibrosis as well. CONCLUSION: TH level significantly influences on the pathomorphological changes in the male and female reproductive system. Scripta Scientifica Medica 2013; 45(4): 77-83.