The effect of neonatal immune challenge on reproduction by altering intraovarian kisspeptin/GPR54 system in the rat

Abstract Immune challenge in early life has been observed to influence the long-term reproductive dysfunction. On PNDs 3 and 5, female offsprings were administered with LPS (50 μg/kg, i.p.) or saline. Vaginal opening was recorded, and oestrous cyclicity was monitored immediately post puberty and again at 56–70 days. At 10 weeks of age, the ovaries were removed for immunostaining and RNA analysis. Neonatal exposure to LPS resulted in a significant delay puberty onset as well as destroyed expression of ovulation related genes. At PND 42 and 70, a significant increase in Kiss1 mRNA and Kisspeptin expression was detected at proestrus and oestrus in neo-LPS treated rats compared with the counterparts. Therefore, neonatal LPS exposure had a long-term effect on reproductive function and the up-regulated expression of ovarian Kiss1 and kisspeptin during the ovulatory transition stage may contribute to ovulatory dysfunction induced by peripheral LPS administration in early life.