In utero exposure to diethylstilboestrol or 4-n-nonylphenol in rats: number of sertoli cells, diameter and length of seminiferous tubules estimated by stereological methods.

The effects on testis weight and histopathology were studied in 11-day-old male Wistar rats after prenatal exposure to peanut oil (control), diethylstilboestrol 30 microg/kg b.wt./day, or 4-n-nonylphenol 75 mg/kg b.wt./day from gestational day 11 to 18. Additionally, the diameter and length of seminiferous tubules, and the number of Sertoli cells were investigated with stereological methods. Such unbiased methods have not previously been applied on testis diameter and length or on Sertoli cell number of 11-day-old rats. In the control group, the mean length of the seminiferous tubule was 3.0 m+/-0.6, the mean diameter of the seminiferous tubule was 83 microm+/-6, and the mean number of Sertoli cells was 26.1x10(6)+/-4.6. No differences in testis weight, histopathology, or length or diameter of the seminiferous tubules were observed in the diethylstilboestrol and nonylphenol exposed groups when compared to the control group. In the diethylstilboestrol-treated group, a statistically significant decrease in the number of Sertoli cells was observed (P<0.01) when compared to the control group, whereas nonylphenol had no effect. The result suggests that diethylstilboestrol decreases Sertoli cell proliferation in the foetal testis and furthermore indicate that oestrogens may pose a risk to the reproductive capacity in sensitive species, including man.