The effect of Escherichia coli lipopolysaccharide and tumour necrosis factor alpha on ovarian function

Problem
Pelvic inflammatory disease and metritis are important causes of infertility in humans and domestic animals. Uterine infection with Escherichia coli in cattle is associated with reduced ovarian follicle growth and decreased estradiol secretion. We hypothesized that this effect could be mediated by the bacterial lipopolysaccharide (LPS) or cytokines such as tumour necrosis factor alpha (TNFα).

Method of study
In vitro, bovine ovarian theca and granulosa cells were treated with LPS or TNFα and steroid secretion measured. In vivo, the effect of LPS or TNFα intrauterine infusion was determined by ovarian ultrasonography and measurement of hormones in cattle.

Results
Lipopolysaccharide reduced granulosa cell estradiol secretion, whilst TNFα decreased theca and granulosa cell androstenedione and estradiol production, respectively. In vivo, fewer animals ovulated following intrauterine infusion with LPS or TNFα.

Conclusion
Lipopolysaccharide and TNFα suppress ovarian cell function, supporting the concept that pelvic inflammatory disease and metritis are detrimental for bovine ovarian health.