Cytokine signalling in rat pulp interstitial fluid and transcapillary fluid exchange during lipopolysaccharide-induced acute inflammation
Cytokine signalling in rat pulp interstitial fluid and transcapillary fluid exchange during lipopolysaccharide-induced acute inflammation
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DOI：
10.1113/jphysiol.2006.104711
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发表时间：
2006-05-15
影响因子：
5.5
通讯作者：
Wiig, Helge
中科院分区：
文献类型：
--
作者：
Bletsa, Athanasia;Berggreen, Ellen;Wiig, Helge
牙髓由包裹在坚硬的牙本质壁中的疏松结缔组织组成。由于其地形，组织具有低的间质顺应性和有限的能力，以扩大在流体体积变化。由于组织间液获取的局限性，对该器官缺乏经毛细血管液体转运参数的基本知识。该项目的范围是双重的：首先，我们旨在建立一种方法，用于分离牙髓间质液（IF），其次，我们应用该方法在大鼠脂多糖（LPS）诱导的内毒素血症。目的是测量急性炎症期间牙髓IF中的胶体渗透压（COP）和促炎细胞因子。测量液体体积和牙髓血流量（PBF），以获得更多关于在该牙髓炎模型中发生的微循环变化的信息。通过在239 g下离心切牙牙髓，我们能够提取代表IF的流体。牙髓IF具有相对高的对照COP（类似于血浆COP的83%），并且在LPS攻击后3小时类似于血浆COP。果肉表现出高含量的IF（0.60 +/-0.03ml（g湿重）（-1））和0.03 +/-0.01ml（g w.w.）(-1)LPS暴露1.5和3 h后，未观察到液体体积分布差异。注射LPS后PBF和体循环血压显著下降。PBF仍然很低，而全身血压在3小时内重新建立，这意味着器官功能障碍。牙髓IF和血清中细胞因子表达的模式不同，局部产生的细胞因子如IL-1 α、IL-1 β和TNF-α，而全身产生的其他细胞因子如IFN-γ和IL-6可能在LPS暴露后溢出到牙髓IF。我们的研究结果表明，纸浆IF可以通过离心分离，这种方法是有用的，当研究流体平衡和细胞外信号机制在正常和病理条件下的牙髓。
The dental pulp consists of loose connective tissue encased in rigid dentinal walls. Because of its topography the tissue has low interstitial compliance and limited capacity to expand during fluid volume changes. Due to limitations regarding access to interstitial fluid, basic knowledge on transcapillary fluid transport parameters is lacking for this organ. The scope of this project was dual: first we aimed at establishing a method for isolation of pulp interstitial fluid (IF), and second we applied the method in rats subjected to lipopolysaccharide (LPS)-induced endotoxaemia. The aim was to measure colloid osmotic pressure (COP) and pro-inflammatory cytokines in the pulp IF during acute inflammation. Fluid volumes and pulpal blood flow (PBF) were measured to obtain more information about microcirculatory changes that take place in this pulpitis model. By centrifugation of incisor pulp at 239 g we were able to extract fluid representative for IF. Pulp IF had a relative high control COP (similar to 83% of plasma COP) and was similar to plasma COP 3 h after LPS challenge. The pulp exhibited a high content of IF (0.60 +/- 0.03 ml (g wet weight)(-1)) and a vascular volume of 0.03 +/- 0.01 ml (g w.w.)(-1) No differences were observed in the distribution of fluid volumes after 1.5 and 3 h LPS exposure. PBF and systemic blood pressure dropped significantly after LPS administration. PBF remained low whereas systemic blood pressure was re-established during the 3-h period, implying organ dysfunction. There was a differential pattern of cytokine expression in pulp IF and serum with cytokines such as IL-1 alpha, IL-1 beta and TNF-alpha locally produced, whereas others such as IFN-gamma and IL-6 were produced systemically and probably spilled over to the pulp IF after LPS exposure. Our findings show that pulp IF can be isolated by centrifugation and that this method is useful when studying fluid balance and extracellular signalling mechanisms in the dental pulp in normal and pathological conditions.