Prenatal exposure to diesel exhaust impairs mouse spermatogenesis

The effect of prenatal exposure to diesel exhaust (DE) was investigated. Twenty pregnant ICR mice were exposed to DE at the particle concentration of 1.0 mg/m3, from d 2 until d 16 postcoitum. Male offspring were kept alive until 12 wk of age, and then male reproductive organ weight, daily sperm production (DSP), serum testosterone level, and mRNA expression of sex steroid hormone synthesis process-related factors were measured. Serum testosterone levels of the exposed group were reduced significantly at 3 wk, whereas they were elevated significantly at 12 wk. DSP was also markedly reduced at 5 and 12 wk. Histological examination showed multinucleated giant cells in the seminiferous tubules of the exposed group as well as partial vacuolation of the seminiferous tubules. Follicle-stimulating hormone receptor (FSHR) mRNA expression and steroidogenesis acute regulatory (StAR) protein were significantly increased at 5 wk and 12 wk, respectively. This study suggests that prenatal exposure to DE has detrimental effects on mouse spermatogenesis in offspring.