Effect of di-(2-ethylhexyl) phthalate on N-cadherin and catenin protein expression in rat testis.

This study investigated the effect of DEHP exposure on N-cadherin and alpha-, beta- and p120-catenin immunoreactivities in the rat testis. DEHP was administered by daily gavage to 25-day-old male Sprague-Dawley rats at a dose of 2 g DEHP/5 ml corn oil/kg body weight for 2 days or 7 days. Control rats were treated with corn oil vehicle under the same conditions. Animals were killed at 24h after the last treatment. Another group of rats treated with DEHP or corn oil vehicle (control group) for 2 days were held for 30 days without treatment to observe recovery. Testes were analyzed for histopathology, TUNEL staining, immunofluorescence (IF) and Western blot analyses. Animals exposed to DEHP for 2 days or 7 days showed severe alterations of seminiferous tubules characterized by germ cell sloughing. Animals from the longer term recovery group treated with DEHP showed foci of delayed spermatogenesis. A linear and continuous pattern of N-cadherin was observed in the basal compartment of the seminiferous tubules. A similar pattern but with higher IF intensity was observed for N-cadherin in rats treated with DEHP for 2 days or 7 days, compared to control animals. The alpha-, beta- and p120-catenins were detected in the basal compartment of seminiferous tubules in similar localization and IF pattern for DEHP and control groups. A significant increase in testicular N-cadherin and alpha-catenin levels was detected by Western blot analysis in DEHP-exposed versus control rats. No variations in N-cadherin or catenin expression were detected in the recovery groups. These findings demonstrate that DEHP induces an up-regulation of N-cadherin and alpha-catenin expression and may perturb cell-cell adhesion phenomena in the seminiferous tubule.