Chronic Exposure to Perfluorohexane Sulfonate Leads to a Reproduction Deficit by Suppressing Hypothalamic Kisspeptin Expression in Mice

Abstract

BackgroundPerfluorohexane sulfonate (PFHxS) is a six-carbon perfluoroalkyl sulfonic acid found as an environmental contaminant. This study aims to investigate the effects of PFHxS exposure on female reproduction and the underlying mechanism in mice. MethodsEight-week-old ICR mice were divided randomly into four groups: corn oil (vehicle) and PFHxS at doses of 0.5, 5, and 50 mg/kg/day for 42 days by intragastric administration. Body weight, ovarian weight, estrous cycle, follicle counts, and serum sex hormone levels were evaluated. Expression of kisspeptin and gonadotropin releasing hormone (GnRH) in the hypothalamus was also detected. ResultsCompared to vehicle exposure, 5 mg/kg/day PFHxS prolonged the estrous cycle, especially the duration of diestrus, after 42 days of treatment. The numbers of antral follicles and corpus lutea were significantly reduced in PFHxS-treated mice. Moreover, compared with the control group, PFHxS-treated mice showed decreases in serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estrogen (E2), and reduced GnRH mRNA levels, along with the lack of an LH surge. Furthermore, PFHxS-treated mice had lower levels of kisspeptin immunoreactivity and kiss-1 mRNA in the arcuate nucleus (ARC) and anteroventral periventricular nucleus (AVPV). After intraventricular administration of kisspeptin-10, the numbers of antral follicles and corpus lutea recovered, along with the levels of GnRH mRNA, FSH, and LH in mice treated with 5 mg/kg/day PFHxS. ConclusionThese results indicate that chronic exposure of mice to 5 mg/kg/day PFHxS affects reproductive functions by inhibiting kisspeptin expression in the ARC and AVPV regions, leading to the deficit of follicular development and ovulation.