Abstract

The successful of pregnancy in humans and rodents occur between the interaction maternal and fetal interface, specially involving the participation of uNK cells. This interaction involved neo angiogenesis, placentation and presence of mediators like nitric oxide. During the pregnancy the administration of LPS in the dams can results in necrosis, preterm birth, IUGR, miscarriage or neurological problem. Once the uNK cells are activated, they can produce vasodilators, like NO. So, the main purpose of this study was to evaluate if LPS cause alteration in the uNK cells in pregnant mice and if the same behaviour can be detected by NO in the blood. Also we evaluated the effect of LPS to cause neurological injuries. To do that we used pregnant mice on gd 10th and those was treated with LPS for different times. Uterine samples were collected at 0.5,1,2 and 6hr after LPS treated and processed for paraffin embedding and tissue homogenate. The samples designated for paraffin embedding was performed the Dolichos biflorus (DBA) lectin cytochemistry and anti-iNOS immunocytochemistry. The samples designated to tissue homogenates were processed for SDS-PAGE and Western-blot using anti-iNOS and evaluate of NO concentration. We found after 2h LPS exposure the mice showed fever and low capacity to explore different environment. At the same time, we found increase in the nitrate/nitrito ratio in a dose dependent manner in the uterus after 2h LPS exposure. The uNK cells were the main cell that was staining for iNOS isoform. Also, we found that wall:lumen ratio is very higher in treated mice than the control mice. The LPS is able to induce the activation of uNK cells and this action is involved by releasing NO in higher amount. So, it is possible to consider the uNK cells as a potential element of maternal-fetal interface in the production of NO and knowing that the isoforms is reduced in these cells, a model of NOS inhibition could be considered to elucidate the participation of uNK cells as a possible cause of effectors loss or interruption of pregnancy [1-7].

Keywords:LPS; uNK cells; Pregnancy; NO concentration