Abstract:

Objective　To investigate the effects of endotoxemia in neonatal rats on ovarian development.　Methods　A total of 60 neonatal Sprague-Dawley female rats were used in this study. The litters were randomly divided into either LPS-treated or saline control groups. These rats were administered 75 μg/kg LPS or an equivolume of non-pyrogenic saline via subcutaneous injection on alternate day from postnatal days 4 to 12. All the rats were then fed conventionally and their body weight, the day of vaginal opening (dVO), the day of first vaginal estrus and estrous (sexual) cycle were monitored dynamically. The rats were sacrificed on postnatal day(PND)14，dVO and PND77, respectively after the weight was measured. bilateral ovaries were harvested and weighted for calculation of organic coefficient. Histological changes of ovaries were observed by means of conventional paraffin sectioning.　Results 　① LPS-treated rats exhibited a decrease in the weight of body and ovary, and a significant delay in both the day of vaginal opening and the day of first vaginal estrus. ②LPS treatment could cause vasocongestion and angiectasis, interstitial edema in the ovaries of female rats in the immediate term，and contributed to a decrease in normal follicles, an increased in atretic follicles and prolonged estrous cycle in the late period.　Conclusion　Neonatal endotoxemia may affect the growth and development of female rats, and result in a delayed puberty, sexual cycle disorder and a decreased follicular reserve in female rats.

Key words: Ovary；　Neonatal period；　Lipopolysaccharide(LPS), 　Rats