['The potency of acute montelukast treatment, a leukotriene receptor antagonist, has been demonstrated as tocolytic on in vitro myometrial contractility. This study assessed the ability of a 48h montelukast treatment to modify in vitro contractions under inflammatory conditions in a pregnant rat model.', 'Pregnant Sprague-Dawley rats were injected intraperitoneally (gestational days 20-22) with lipopolysaccharides (LPS) 200μg/kg (4 treatments at 12h intervals) alone or combined with montelukast 10mg/kg/day or a saline solution for a 48h period. Uterine rings (n=72) were obtained by median laparotomy at day 22. Spontaneous contractile activities were compared using pharmacological compounds (oxytocin, nifedipine) along with assessment of contractile parameters. Myometrial subcellular fractions were also analyzed by Western blot to quantify oxytocin, cysteinyl leukotriene receptors and inflammation markers.', 'In in vitro experiments, the area under the curve, the amplitude and the duration of phasic contractions were significantly reduced following 48h of LPS+montelukast treatment comparatively to the LPS group. Moreover, in this same group, oxytocin (10'] Does antenatal montelukast treatment reduce uterine activity associated with inflammation in a pregnant rat model?