Immunoexpressions of embryonic and nonembryonic stem cell markers (Nanog, Thy-1, c-kit) and cellular connections (connexin 43 and occludin) on testicular tissue in thyrotoxicosis rat model

In this study, possible thyrotoxicosis-related histological changes in testicular tissues of rats with experimentally induced thyrotoxicosis model were evaluated on cellular connections and stem cell markers. Two experimental groups, thyrotoxicosis and control, each consisting of eight animals were used. Rats in the thyrotoxicosis group were injected intraperitoneally with 3,3',5-triiodo-l-thyronine (50 µg/100 g body weight/day) for 10 days. At the end of the study, animals in both groups were anesthetized, and blood samples were collected for biochemical analyses. Their testes were dissected out and histological procedure was conducted to perform further histochemical, immunohistochemical analyses and tissue expression analysis by real-time polymerase chain reaction. Expression of the stem cell markers such as c-kit and Thy-1 significantly decreased in the testes of the thyrotoxicosis group compared with the control group; however, Nanog expression was not detected in any of the groups. Similarly, connexin 43 and occludin expressions were also found to be significantly lower in the thyrotoxicosis group. These results on cellular connections are supported with the tissue expression analysis. Our findings are indicative of supporting microenvironmental tissue decay rather than parenchyma damage, which has been actually ignored in the literature. In conclusion, experimental thyrotoxicosis model may have adverse effects on the cell junctional complexes, cell-cell interactions, and pluripotency capacity.