the impact of intermittent umbilical cord occlusions on the inflammatory response in pre-term fetal sheep断断续续的脐带遮挡的影响在炎症反应和早产胎羊.pdf

The Impact of Intermittent Umbilical Cord Occlusions on the Inflammatory Response in Pre-Term Fetal Sheep 1,2 1 2 3 1 Andrew P. Prout , Martin G. Frasch , Ruud Veldhuizen , Rob Hammond , Brad Matushewski , Bryan S. Richardson1,2* 1 Department of Obstetrics and Gynaecology, The University of Western Ontario, London, Ontario, Canada, 2 Department of Physiology and Pharmacology, The University of Western Ontario, London, Ontario, Canada, 3 Department of Pathology, The University of Western Ontario, London, Ontario, Canda Abstract Fetal hypoxic episodes may occur antepartum with the potential to induce systemic and cerebral inflammatory responses thereby contributing to brain injury. We hypothesized that intermittent umbilical cord occlusions (UCOs) of sufficient severity but without cumulative acidosis will lead to a fetal inflammatory response. Thirty-one chronically instrumented fetal sheep at ,0.85 of gestation underwent four consecutive days of hourly UCOs from one to three minutes duration for six hours each day. Maternal and fetal blood samples were taken for blood gases/pH and plasma interleukin (IL)-1b and IL-6 levels. Animals were euthanized at the end of experimental study with brain tissue processed for subsequent counting of microglia and mast cells. Intermittent UCOs resulted in transitory fetal hypoxemia with associated acidemia which progressively worsened the longer umbilical blood flow was occluded, but with no cumulative blood gas or pH changes over the four days of study. Fetal arterial IL-1b and IL-6 values showed no significant change regardless of the severity of the UCOs, nor was there any evident impact on the microglia and mast cell counts for any of