Effects of pre- and post- natal exposure to flutamide on connexin 43 expression in testes and ovaries of prepubertal pigs

The aim of this study was to show whether connexin43 (C×43) expression in gonads is affected by an anti-androgen action. To perform this test, pigs were prenatally (on gestational days 20–28 and 80–88; GD20, GD80) and postnatally (on days 2–10 after birth; PD2) exposed to flutamide, which was given in five doses every second day and its effect was observed in prepubertal gilts and boars. Morphology and expression of C×43 was investigated in testes and ovaries by means of routine histology, immunohistochemistry, Western blotting, and RT-PCR. In boars exposed to flutamide varying degrees of seminiferous tubule abnormality, including reduced number of Sertoli cells, tubules with severely dilated lumina and multinucleated germ cells were observed, whereas in gilts, the administration of flutamide at GD20 resulted in delayed folliculogenesis. Only follicles at the preantral stage were observed. Qualitative analysis of immunohistochemical staining for C×43 was confirmed by quantitative image analysis, where the staining intensity was expressed as relative optical density of diaminobenzidine deposits. After flutamide exposure, statistically significant increase in C×43 signal intensity was observed between interstitial tissue of GD20 and control pigs (**P<0.01), between seminiferous tubules of PD2 and control boars (**P<0.01) and between theca cells of GD80, of PD2 and control gilts (**P<0.01). In contrast, statistically significant decrease in C×43 signal intensity was found between granulosa cells of GD20, of PD2 and control gilts (**P<0.01 and *P<0.05, respectively) and between theca cells of GD20 and control gilts (**P<0.01). Since we demonstrated changes in gonad morphology and in the expression of C×43 at the level of protein of prepubertal boars and gilts, it seems possible that flutamide, through blocking androgen action, causes delayed gonadal maturation in later postnatal life and, among other factors, may be involved in the regulation of C×43 gene expression in pig gonads

Connexin 43 expression in human and mouse testes with impaired spermatogenesis

Connexin 43 (Cx43) belongs to a family of proteins that form gap junction channels. The aim of this study was to examine the expression of Cx43 in the testis of a patient with Klinefelter’s syndrome and of mice with the mosaic mutation and a partial deletion in the long arm of the Y chromosome. These genetic disorders are characterized by the presence of numerous degenerated seminiferous tubules and impaired spermatogenesis. In mouse testes, the expression and presence of Cx43 were detected by means of immunohistochemistry and Western blot analysis, respectively. In testes of Klinefelter’s patient only immunoexpression of Cx43 was detected. Regardless of the species Cx43 protein was ubiquitously distributed in testes of reproductively normal males, whereas in those with testicular disorders either a weak intensity of staining or no staining within the seminiferous tubules was observed. Moderate to strong or very strong staining was confined to the interstitial tissue. In an immunoblot analysis of testicular homogenates Cx43 appeared as one major band of approximately 43 kDa. Our study adds three more examples of pathological gonads in which the absence or apparent decrease of Cx43 expression within the seminiferous tubules was found. A positive correlation between severe spermatogenic impairment and loss of Cx43 immunoreactivity observed in this study supports previous data that gap junctions play a crucial role in spermatogenesis. Strong Cx43 expression detected mostly in the interstitial tissue of the Klinefelter’s patient may presumably be of importance in sustaining Leydig cell metabolic activity. However, the role of gap junction communication in the control of Leydig cell function seems to be more complex than originally thought

Dose-and photoperiod-dependent effects of 17 BETA-estradiol and the anti-estrogen ICI 182,780 on testicular structure, acceleration of spermatogenesis, and aromatase immunoexpresion in immature bank voles

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