Fusshoeller Andreas, Baehr Jessica, Grabensee Bernd, Plum Joerg
Department of Nephrology and Rheumatology, Heinrich-Heine University of Düsseldorf, Germany.
Perit Dial Int. 2005 Jul-Aug;25(4):387-93.
In peritoneal dialysis (PD), neutrally buffered PD fluids with lower concentrations of glucose degradation products (GDP) have tested superior to conventional fluids in terms of biocompatibility. However, conventional in vitro studies provoke debate because, due to the lack of subsequent equilibration with the blood, they do not resemble the true intraperitoneal situation of PD.
We established a double-chamber cell culture system with peritoneal mesothelial cells seeded on top of a permeable membrane, with a physiological buffer below. Thus adequately reflecting the in vivo equilibration pattern, we compared a conventional fluid with a neutral bicarbonate/lactate-buffered PD solution. Using an exchange pattern adapted from an 8-hour continuous ambulatory PD regimen, cell viability was assessed with an MTT assay, and cell function via constitutive and stimulated interleukin (IL)-6 release. As an indicator of potential induction of fibrosis and as a parameter of mesothelial cell integrity, respectively, transforming growth factor-beta 1 (TGF-beta1) generation and cancer antigen 125 (CA125) release were measured.
The conventional solution significantly compromised mesothelial cell viability and function in terms of mitochondrial activity (p < 0.05) and stimulated IL-6 release (p < 0.05). The bicarbonate/lactate fluid had no effect on cell viability or IL-6 release and turned out to be equivalent to the properties of the growth medium. Whereas lactate-incubated cells did not respond to IL-1beta stimulation, bicarbonate/lactate-treated cells adequately increased IL-6 release after stimulation (p < 0.0005). Release of TGF-beta1 and CA125 did not differ between the different fluids and the control.
Due to the sustained equilibration process, the double-chamber cell culture model allows a more realistic insight into mesothelial cell viability and function in terms of PD. As in classic in vitro studies, an adverse effect of conventional PD solutions on mesothelial cells was overt in the present cell culture system. The neutral bicarbonate/lactate-buffered fluid with low GDP content, however, did not interfere with mesothelial cell vitality or function, indicating superior biocompatibility.
在腹膜透析（PD）中，葡萄糖降解产物（GDP）浓度较低的中性缓冲腹膜透析液在生物相容性方面已被证明优于传统透析液。然而，传统的体外研究引发了争议，因为由于缺乏与血液的后续平衡，它们并不类似于PD的真实腹膜内情况。
我们建立了一个双室细胞培养系统，腹膜间皮细胞接种在可渗透膜上，下方是生理缓冲液。通过采用模拟8小时持续非卧床腹膜透析方案的交换模式，我们用MTT法评估细胞活力，并通过组成性和刺激后的白细胞介素（IL）-6释放来评估细胞功能。分别作为潜在纤维化诱导指标和间皮细胞完整性参数，测量转化生长因子-β1（TGF-β1）生成和癌抗原125（CA125）释放。
传统透析液在细胞线粒体活性（p<0.05）和刺激后的IL-6释放方面（p<0.05）显著损害间皮细胞活力和功能。碳酸氢盐/乳酸盐透析液对细胞活力或IL-6释放没有影响，结果显示其性质与生长培养基相当。乳酸孵育的细胞对IL-1β刺激无反应，而碳酸氢盐/乳酸盐处理的细胞在刺激后能充分增加IL-6释放（p<0.0005）。不同透析液与对照之间TGF-β1和CA125的释放没有差异。
由于持续的平衡过程，双室细胞培养模型能够更真实地洞察腹膜透析中间皮细胞的活力和功能。与经典体外研究一样，在本细胞培养系统中，传统腹膜透析液对间皮细胞的不良影响很明显。然而，低GDP含量的中性碳酸氢盐/乳酸盐缓冲液不会干扰间皮细胞活力或功能，表明其具有更好的生物相容性。
