Xenoestrogens diethylstilbestrol and zearalenone negatively influence pubertal rat's testis.

Abstract

Abstract:The aim of this study was to assess the impact of xenoestrogens: diethylstilbestrol (DES) and zearalenone (ZEA) on rat's pubertal testis and to compare it with the effect of natural estrogen -17β-estradiol (E). Male Wistar rats were daily, subcutaneously injected at 5 th -15 th postnatal days (p.d.) with E (1.25 or 12.5 μg) or DES (1.25 or 12.5 μg) or ZEA (4 or 40 μg) or vehicle. At 16 th p.d. testes were dissected, weighted, and paraffin embedded. Following parameters were assessed: diameter and length of seminiferous tubule, numbers of spermatogonia A+intermediate+B (A/In/B), preleptotene spermatocytes (PL), leptotene+zygotene+pachytene spermatocytes (L/Z/PA) and Sertoli cells per testis. Testes weight, seminiferous tubule diameter and length were decreased by both doses of E, DES and ZEA. DES effect was the strongest, but its influence on testis weight and seminiferous tubule length, on the contrary to E and ZEA, was not dose-dependent. Similarly, DES in both doses had the most severe negative impact on the number of germ and Sertoli cells. The negative influence of E on germ cells was less pronounced. The negative effect of ZEA was seen only after administration of the higher dose on spermatogonia number, while DES and E decreased A/In/B number more evidently. Sertoli cell number were decreased after both doses of E. ZEA40 decreased Sertoli cell number while ZEA4 had no effect. Conclusion: exposure of prepubertal male rat to DES has the strongest detrimental effect on the developing testis in comparison to E and ZEA. Both, E and DES, decreased number of germ and Sertoli cells, diminished seminiferous tubule diameter, length and testis weight. ZEA had much more weaker effect than the potent estrogens.

Di(n-butyl) phthalate has no effect on the rat prepubertal testis despite its estrogenic activity in vitro

“…The autopsy was performed on the 16 th pd to observe the possible disturbances caused by DBP within a short time following treatment. Such rapid disruptive actions have previously been observed for different xenoestrogens [8] and hormones [20]. All the sacrificed animals were weighed.…”

“…Neither testis weight and morphology, nor testosterone, estradiol or FSH serum levels were affected. In the same study model, 17b-estradiol, diethylstilbestrol (DES) and zearalenone (ZEA) showed a negative impact on testicular development even when administered in lower doses [8]. The majority of reports on DBP's influence on the male reproductive tract describe treatment with doses of around 500 mg/kg b.w.…”

“…Estrogenic compounds are known to possess a similar biphasic effect. Although the high doses of estrogenic substances have a negative impact on testis development and initiation of spermatogenesis [8][9][10], lower doses have a stimulatory effect [10][11][12]. The stimulatory effect of estradiol on spermatogonia number/ /proliferation has been confirmed by recent studies [13,14].…”

“…Seminiferous tubule examinations were performed as described previously to assess the diameter, length and number of germ and Sertoli cells per testis [8]. The percentage of seminiferous tubules containing gonocytes (G) or spermatocytes in the pachytene stage of first meiotic division (ScPa) or lumen was obtained by counting 100 randomly-selected round seminiferous tubules.…”

Of Oestrogens and Sperm: A Review of the Roles of Oestrogens and Oestrogen Receptors in Male Reproduction

“…The negative effect was observed even in men of the F2 generation whose fathers had been exposed to DES in utero [176]. The adverse effect of DES on male fertility was also proven in rats [177] and mice [178,179]. One possible mechanism was suggested in a study showing that the neonatal DES exposure induced alterations in the DNA methylation status of seminal vesicle secretory protein IV (Svs4) and lactoferrin (Ltf) genes in seminal vesicles of adult mice [180].…”