Effect of diethylhexyl phthalate on proliferation of ED1-testicular macrophages in rats

Bis(2-ethylhexyl) phthalate (DEHP) is a commonly used plasticizer in many toys, consumer products and medical devices. The aim of the present immunohistochemical work was to study the effect of DEHP on macrophage proliferation in the testis of pubertal rats. Twenty-day old rats (Rattus norvegicus) were gavaged with DEHP (200 mg/kg) or the corn oil vehicle (control) for 10, 20, and 30 days. Using the specific antibody ED1 we have determined the number of macrophages (per mm^2 in paraffin sections) after the DEHP treatment. The treatment of animals with DEHP significantly increased the macrophage numbers in the testis compared to control. This is true for all three durations of treatment. The macrophages were quantified according to the location in the testis: (1) peritubular, (2) Leydig cell vicinity, (3) perivascular. The data showed that the highest number of macrophages was of peritubular location. To conclude, the significant increase of the macrophage number in the testis of DEHP-treated rats can be interpreted as an expression of the inflammatory and/or apoptotic processes.