Hypothyroidism effects on the morpho-histometrical features of testes in adult rats

Background: Up until now, the effect of thyroid hormones on the male reproductive organ, after puberty, is not well understood. OBJECTIVES: In the present study, the morpho-histometrical effects of thyroid hormone deficiency on the adult-male rat reproductive organs were investigated. MATHODS: Thirty adult male rats were randomly divided into three groups (n=10): control, hypothyroid, and hypothyroid which receives Levothyroxine. After 4-months we examined the number of spermatogonia cells, primary spermatocytes, and Sertoli cells, as well as the seminiferous tubules epithelium thickness, area of seminiferous tubules, and the diameter and thickness of testis artery walls. RESULTS: No significant difference was observed between the hypothyroid and control rats in terms of the area of seminiferous tubules, the number of spermatogonia cells, primary spermatocytes, and Sertoli cells. Moreover, the epithelium thickness of seminiferous tubules and the diameter and thickness of artery walls were significantly decreased in hypothyroid group compared with the control rats. CONCLUSIONS: These observations are consistent with the hypothesis that hypothyroidism can affect the male fertility and declare that it may influence male reproduction by reducing the testis blood flow.