The Toxicity Of BPAF On Prepubertal Male Rat Testis

Bisphenol analogues are a kind of industrial chemicals, which have been widely used in the industry as well as in our daily life. Due to their characteristics of being difficult to degrade and easy to enrich, they have the potential harm to the environment. At the same time, as bisphenol analogues are endocrine disrupting compounds (EDCs), their potential toxicity effects have drawn more and more attention. With the restrictions on the use of Bisphenol A (BPA), Bisphenol AF (BPAF) was widely used in many fields, including fluorinated rubber, food packaging, and pharmaceutical intermediates, instead. Recent research implicated that BPAF has stronger activity of endocrine disruption like BPA. Previous study indicated that BPAF has estrogenic activity and anti-androgenic activity. But for prepubertal young rats, due to their immature hypothalamus-pituitary-gonadal axis, they have low sexual hormone levels and probably be more sensitive to exogenous endocrine disrupters. Up to now, toxicity effects of BPAF exposure through uterine and milk have not been investigated.In this research, female SD rats were exposed with BPAF using cross fostering model to preliminary study the BPAF toxicity effects on prepubertal male rats’testes through uterine exposure and milk exposure. Mother rats were orally dosed for 17 days in each period with BPAF 100mg/kg/d during gestation and lactation.The main results are as follows:1. Body weight of treatment group of mother rats was significantly lower than that of control group. Moreover, body weight of prepubertal male rats which exposed BPAF through milk was lower than control group.2. For prepubertal male rats, BPAF exposure via both uterine and milk led to significant increase of testosterone in serum, and significant up regulation of many genes that related to cholesterol transport and testosterone synthesis, including SR-B1, StAR,3β-HSD, CYP17a,17β-HSD. These results showed that BPAF might stimulate testosterone synthesis by influencing the expression of related genes. At the same time, the increase of AMH level and inhibin B level indicated that BPAF might interfere with development and sperm production functions of testis.3. BPAF exposure via uterine and milk resulted in increase of triglyceride level in prepubertal male rats’serum. Genes related to lipid transport, catabolism and synthesis up regulated in testis demonstrated that BPAF might interfere with lipid metabolism in testis. Many of these genes are downstream genes of Peroxisome proliferator activated receptor (PPARs), implied a pivotal role of PPARs in the process of BPAF interfering lipid metabolism.4. Uterine exposure of BPAF caused increasing level of thyroxine and triiodothyronine of prepubertal male rats, which showed a potential thyroid toxicity of BPAF.