Effects of di(2-ethylhexyl)phtalate on gap and tight junction protein expression in the testis of prepubertal rats

SOBARZO C.; LUSTIG L; PONZIO R; DENDUCHIS B

Barcelona

Congreso; 9 Congreso Internacional de Andrología; 2009

Sociedad Internacional de Andrología

  It has been suggested that Sertoli cells are one of the primary cellular targets for di-(2-ethylhexyl) phthalate (DEHP) induced testicular toxicity. The aim of this study was to analyze whether DEHP is able to induce changes in the expression of gap and tight junction proteins in the testes of prepubertal rats. DEHP (1g/kg body weight) was administered for 2 days by gavage to male rats (experimental group). Control rats were treated with corn-oil vehicle. Animals were killed 24 h after the last treatment. Testes were processed for light and electron microscopy, immunofluorescence (IF) and Western blot (Wb). Testes of experimental rats showed alterations of seminiferous tubules characterized by different degrees of germ cell sloughing.  No changes were observed in the permeability of the blood testis barrier analized by electron microscopy using lanthanum. A lower expression of connexin 43 (Cx 43) in the adluminal compartment of seminiferous tubules from rats treated with DEHP compared to controls was observed by IF.  Occludin and zonula occludens-1 (ZO-1) were detected by IF in the basal compartment of seminiferous tubules, with a different pattern for ZO-1: discontinuous for experimental rats and continuous for control rats.  By Wb, a significant decrease in Cx43 and ZO-1 expression was observed in the testis lysates of experimental rats compared to control rats while no changes in occludin expression were detected. In conclusion, DEHP induces germ cell sloughing and down regulation of Cx43 and ZO-1 expression suggesting alterations in the intercellular communications of the seminiferous tubules.