Neonatal exposure to T3 disrupts male reproductive functions by altering redox homeostasis in immature testis of rats

Efficacy of ozone versus mesenchymal stem cell-derived microvesicles in ameliorating testicular changes after hypothyroidism in adult albino rats: a histological and immunohistochemical study

This study was performed to: detect the histological, immunohistochemical, and biochemical alterations that may occur in the testes of adult rats in induced hypothyroidism. And to investigate which one, ozone or MSCs-MVs have better therapeutic effect on testicular changes after hypothyroidism. Eighty-four male adult rats were separated into: control group, hypothyroidism group: rats will be given carbimazole for 30 days, ozone group: rats treated as hypothyroidism group then will be injected with ozone intraperitoneal for 7 days. MSC-MVs group: rats treated as hypothyroidism group then will be injected with a single intravenous dose MSC-MVs. Specimens of testes were handled for light, electron microscope, and immunohistochemical of vimentin and S100. Biochemical analysis for; MDA and TNFα; serum testosterone, TSH, T3, and T4 was done, also, sperm count and morphology assay. Morphometric and statistical analysis were performed. Hypothyroidism group showed disorganized seminiferous tubules. A noticeable gap was between the basement membrane and the germinal epithelium. Wide interstitium had congested vessels and acidophilic homogenous material. Vacuolated germinal epithelium and few germ cells had dark nuclei with noticeable separation of between the basement membrane and the germinal epithelium. Ozone and MSCs-MVs induced improvement in all the previous parameters and restoration of spermatogenesis. In Conclusion MSCs-MVs has better ameliorative effect than ozone on hypothyroidism-exposed testes.

Selenium protects against nesfatin-1 modulation of the hypothalamic-pituitary-testicular axis during hypothyroidism in male rats

Normal gonadal function can be disrupted by hypothyroidism. Hypothyroidism disturbs testicular function directly and centrally by affecting the hypothalamic-pituitary-testicular axis with unclear mechanism. As nesfatin-1 neurons co-localized with TRH and GnRH neurons in the hypothalamus, it could play a role in centrally hypothyroidism induced testicular dysfunction. Selenium (Se), by affecting thyroid iodide supply, could relieve these disturbances. So, we aim to identify the role of nesfatin-1 as a link between testicular dysfunction and hypothyroidism through modulating the MAPK/ERK pathway while discussing the possible role of Se in alleviating hypothyroidism and associated testicular damage. Forty male rats were divided equally into: Control: distilled water, Se: Se orally, Propylthiouracil (PTU): PTU orally, PTU + Se: Se with PTU orally. Serum thyroid function, gonadal hormones, nesfatin-1, testicular redox status, sperm analysis, brain tissue GnRH, nucleobindin 2-derived polypeptide, pMAPK/ERK gene expression, histological changes and immunohistochemical expression of testicular proliferating cell antigen (PCNA) were done. PTU induced hypothyroidism and reduction of gonadal hormones which both were correlated with reduced nesfatin-1. There was testicular stress with reduced GnRH, NUCB2, pMAPK/ERK gene expression, and PCNA immunopositive cells. These parameters were reversed by Se. Nesfatin-1 could be the central link between hypothyroidism and disturbances of the hypothalamic pituitary testicular axis.

Impaired sperm quantity and motility in adult rats following gestational and lactational exposure to environmentally relevant levels of PBDE-47: A potential role of thyroid hormones disruption

Polybrominated diphenyl ethers (PBDEs) are flame retardants and the congener 2, 2', 4, 4'-tetrabromodiphenyl ether (PBDE-47) is capable of inducing thyroid endocrine disruption and developmental toxicity. However, little is known about whether developmental PBDE-47 exposure-elicited alterations in semen quality is associated with thyroid hormones (THs) perturbation. In this research, we sought to explore the impacts of gestational and lactational PBDE-47 exposure on adult sperm quantity and motility, and its link with THs levels. For this purpose, female Sprague-Dawley rats were administered environmentally relevant PBDE-47 levels (0.1, 1.0, 10 mg/kg/day) by oral gavage from prepregnancy through lactation cessation to achieve early-life exposure of offspring and to mimic the actual exposure. Sperm quantity and motility together with serum THs levels from male offspring were determined on postnatal day 88. In utero and lactational exposure to PBDE-47 boosted the weight gain while reduced the relative testis weight in adult male offspring. These were accompanied with the reductions in sperm counts (total and living sperm counts), the percentage of progressive sperm motility, sperm velocities (curvilinear velocity, straight-line velocity and average path velocity), motion path (beat cross frequency, linearity and wobble) and linear motile sperm parameters (count, motility and concentration). Further studies identified that the levels of serum triiodothyronine (T₃) were increased by PBDE-47 exposure and negatively associated with those differential semen parameters on quantity and motility. Collectively, our results indicate that exposure to low-level PBDE-47 during early-life development impairs semen quality in adult rats, which could be mediated partially by abnormal T₃ levels.