In utero exposure of high-dose di- n-butyl phthalate resulted in opposite effects on testicular cell apoptosis in late embryonic and pubertal male rat offspring.

OBJECTIVE

To investigate the effects of in utero exposure to high-dose di- n-butyl phthalate (DBP) on testicular cell apoptosis in late embryonic and pubertal male rat offspring.

METHODS

Twenty pregnant Sprague-Dawley (SD) rats were divided into two groups. During gestation day (GD) 12 to GD 19, control group was given 1 ml day of olive oil and experimental group was given DBP 500 mg kg day by gavage. On GD 19.5 and postnatal day (PND) 45, the testes were removed. Morphological analysis of the testes was observed by transmission electron microscopy and hematoxylin and eosin (H&E) staining. Testicular cell apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). The expression of Bcl-2, Bax, and p53 was presented by immunohistochemistry (IHC) and western blot. Data of the two groups was compared using independent samples t-test and Mann-Whitney test by SPSS 20.0.

RESULTS

H&E staining showed that spermatogenetic cells were significantly decreased in DBP exposed pubertal rat testis. The apoptosis index of testes in DBP-treated group was significantly lower on GD 19.5 but higher on PND 45 than that of the controls ( p < 0.01). IHC and western blot revealed significantly increased expression of Bcl-2 in GD 19.5 rat testis and Bax and p53 in PND 45 rat testis after DBP exposure, compared with the control ( p < 0.05).

CONCLUSION

In utero exposure of high-dose DBP resulted in opposite effects on testicular cell apoptosis in late embryonic and pubertal rat offspring. The overexpression of Bcl-2, Bax, and p53 might be related to the occurrence of abnormal apoptosis and finally produce male infertility.