Expression of interleukin 8 in mouse endometrium during early pregnancy and its effect on blastocyst implantation

Objective: To study the expression of interleukin-8 (IL-8) in mouse endometrium during early pregnancy and the effect of IL-8 on mouse blastocyst implantatioa Metheds: The localization and quantity of IL-8 expression in mouse endometrium on day 1-6 of pregnancy were studied by immunohistochemistry method and image analysis. The effect of IL-8 on the implantation was observed by injecting IL-8 antibodies into uterine horn of mouse. Results: In the luminal epithelium of endometrium, IL-8 was mainly located in the free surface. The expression of IL-8 was the weakest on day 1 and strongest on day 4, then decreased on day 5, increased again on day 6. In the glandular epithelium of endometrium, the expression of IL-8 was the weakest on day 4, and the strongest on day 5 and day 6. In endometrium stroma cells, the expression of IL-8 was reinforced gradually with the pregnant progress. IL-8 antibody uterine horn injection showed significant repressing effect on mouse blastocyst implantation. Conclusion: These results suggest that IL-8 is persistently expressed in mouse endometrium during the early pregnancy and participates in the regulation process of mouse blastocyst implantation.