Premature labour is defined as uterine contractions with sufficient intensity, duration and frequency to produce progressive cervical effacement and dilatation before 37 weeks of gestation (Carson, 2004). It is one of the leading complications in obstetrics. There is evidence to suggest that hydrogen sulphide is involved in pregnancy and labour. Research has previously shown that H2S can be produced by homogenates of rat and human placenta, fetal membranes and pregnant uterus and that H2S donors, L-cysteine and sodium hydrosulfide, relax pregnant rat uterine smooth muscle in vitro. The aim of the present study was to investigate the production of H2S by isolated cells of the rat placenta, fetal membranes and pregnant myometrium in culture. Cell culture techniques were performed to disperse Chorio-decidual cells from placenta, amnion/chorion/decidual cells from fetal membranes and myometrial smooth muscle. Cells were exposed to 1 mM L-cysteine for 48 hours and evolved H2S was trapped in 1% zinc acetate solution. The resulting sulphide was measured using a standard methylene blue assay and expressed as nM H2S produced per min per 105 cells (mean ± SD). The effect of exposing the cultured cells from the fetal membranes to 1 μg/ml lipopolysaccharide (LPS) on the production of H2S was also investigated. Data were analysed using ANOVA or independent samples T test, as appropriate. Rat myometrial smooth muscle cells have a H2S mean production rate of 3.63±1.21nM/min/105 cells (n=5), Chorio-decidual cells from the placenta have a H2S mean production rate of 45.53± 12.61nM/min/105 cells (n=6) and cells from the fetal membranes have a H2S mean production rate of 1.79±0.62nM/min/105cells (n=5). Chorio-decidual cells from the placenta had a significantly (P<0.001) higher mean production rate of H2S, in comparison to myometrial smooth muscle cells and cells from the fetal membranes. The results show that rat chorion, decidual, amnion and myometrial smooth muscle cells can produce H2S in culture. Chorio-decidual cells from the placenta had the highest production rate of H2S, which could be involved in vasodilation of placental blood vessels or maintaining myometrial quiescence. H2S production from cultured fetal membrane cells did not increase with the addition of LPS suggesting that H2S probably does not act as an inflammatory mediator in this model of intrauterine infection. The H2S system requires further research and could be a future target for intervention in pregnancy and labour.
|Date of Award||2010|