Interleukin-6 Is Neither Necessary Nor Sufficient for Preterm Labor in a Murine Infection Model

Abstract

Objective: The aim of this study was to investigate the role of interleukin 6 (IL-6) in a murine model of bacterially induced preterm delivery.

Methods: On day 14.5 of a 19-20-day gestation, female mice underwent one of two interventions. In experiment 1, pregnant right uterine horns were injected at laparotomy with 0.5-20 μg of recombinant human IL-6 (rhIL-6). In experiment 2, IL-6-deficient (IL-6^-/-) and wild-type control (IL-6^+/+) mice underwent intrauterine inoculation with 10⁵ to 10⁸ heat-killed Excherichia coli organisms. Preterm delivery and maternal survival rates were recorded.

Results: In experiment 1, doses as high as 20 μg of IL-6 per mouse resulted in up-regulation of acute phase reactants but did not cause preterm delivery or other adverse maternal or fetal effects. In experiment 2, in bacterially inoculated mice, the absence of matrnal and fetal IL-6 had no effect on preterm delivery rates.

Conclusion: IL-6 was neither sufficient nor necessary for preterm delivery in these murine models.

Keywords

Interleukin 6 mouse model preterm delivery intrauterine infection parturition

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