Objective: To assess the roles of interleukin-1β, interleukin-8, and fibroblasts in the lower uterine segment during parturition. Methods: Lower uterine segment biopsy specimens were obtained from 36 women undergoing cesarean delivery at various stages of cervical dilation (less than 2 cm, n = 8; 2 to less than 4 cm, n = 9; 4-6 cm, n = 10; more than 6 cm, n = 9). The concentrations of interleukin-1β and interleukin-8 in protein extracts prepared from the tissue samples were measured by enzyme immunoassays. The effect of incubation with interleukin-1β (30 U/mL) on interleukin-8 secretion by lower uterine segment fibroblasts in vitro also was determined. Results: The median interleukin-1β concentration in the specimens increased from 1.3 pg/mg of total protein at less than 2 cm of dilation to 22.2 pg/mg of total protein at 4-6 cm of dilation (P < .05). No further increase was detectable after 6 cm of dilation. The interleukin-8 concentration increased from 17.2 pg/mg of total protein at less than 2 cm of dilation to 2080.7 pg/mg of total protein at 4-6 cm of dilation (P < .05), thus paralleling the increase in interleukin-1β concentration. Interleukin-1β induced a significant increase in interleukin-8 secretion by fibroblasts in vitro, from 0.8 ng/106cells to 35.6 ng/106cells. Conclusion: The increase in interleukin-8 concentration in the lower uterine segment during parturition may be induced by interleukin-1β and fibroblasts may be one of the sources of this interleukin-8.
Winkler, M., Fischer, D. C., Hlubek, M., Van De Leur, E., Haubeck, H. D., & Rath, W. (1998). Interleukin-1beta and interleukin-8 concentrations in the lower uterine segment during parturition at term. Obstetrics and Gynecology, 91(6), 945–949. https://doi.org/10.1016/S0029-7844(98)00098-2