Liu L J, Schlesinger M
Department of Physics, University of Windsor, Windsor, Ontario, Canada N9B 3P4.
J Theor Biol. 2015 Sep 7;380:1-8. doi: 10.1016/j.jtbi.2015.05.012. Epub 2015 May 15.
A correct description of the hydraulic conductivity is essential for determining the actual tumor interstitial fluid pressure (TIFP) distribution. Traditionally, it has been assumed that the hydraulic conductivities both in a tumor and normal tissue are constant, and that a tumor has a much larger interstitial hydraulic conductivity than normal tissue. The abrupt transition of the hydraulic conductivity at the tumor surface leads to non-physical results (the hydraulic conductivity and the slope of the TIFP are not continuous at tumor surface). For the sake of simplicity and the need to represent reality, we focus our analysis on avascular or poorly vascularized tumors, which have a necrosis that is mostly in the center and vascularization that is mostly on the periphery. We suggest that there is an intermediary region between the tumor surface and normal tissue. Through this region, the interstitium (including the structure and composition of solid components and interstitial fluid) transitions from tumor to normal tissue. This process also causes the hydraulic conductivity to do the same. We introduce a continuous variation of the hydraulic conductivity, and show that the interstitial hydraulic conductivity in the intermediary region should be monotonically increasing up to the value of hydraulic conductivity in the normal tissue in order for the model to correspond to the actual TIFP distribution. The value of the hydraulic conductivity at the tumor surface should be the lowest in value.
正确描述水力传导率对于确定实际的肿瘤间质液压力（TIFP）分布至关重要。传统上，人们一直认为肿瘤组织和正常组织中的水力传导率都是恒定的，并且肿瘤的间质水力传导率比正常组织大得多。肿瘤表面水力传导率的突然转变会导致不符合实际的结果（肿瘤表面的水力传导率和TIFP的斜率不连续）。为了简单起见并出于反映实际情况的需要，我们将分析重点放在无血管或血管化不良的肿瘤上，这类肿瘤的坏死主要在中心，血管化主要在外围。我们认为在肿瘤表面和正常组织之间存在一个中间区域。通过这个区域，间质（包括固体成分和间质液的结构与组成）从肿瘤组织过渡到正常组织。这个过程也会使水力传导率发生同样的变化。我们引入了水力传导率的连续变化，并表明为了使模型与实际的TIFP分布相符，中间区域的间质水力传导率应单调增加直至达到正常组织中的水力传导率值。肿瘤表面的水力传导率值应该是最低的。
