Rogachev B, Hausmann M J, Yulzari R, Weiler M, Holmes C, Faict D, Chaimovitz C, Douvdevani A
Department of Nephrology, Soroka Medical Center and Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
Perit Dial Int. 1997 Nov-Dec;17(6):546-53.
To compare the effect of Dianeal and two newly-formulated bicarbonate-based peritoneal solutions on intracellular pH (pHi), tumor necrosis factor-alpha (TNFalpha) mRNA level, and TNFalpha secretion by peritoneal macrophages (PMphi).
Peritoneal macrophages were isolated from dialysates collected after overnight dwells in peritonitis-free continuous ambulatory peritoneal dialysis patients. Dialysis solutions contained 1.5% or 4.25% dextrose. HCO3 concentrations of bicarbonate-(TB) and bicarbonate/lactate-buffered (TBL) solution were 38 mM and 25 mM, respectively. TBL also contained lactate at a concentration of 15 mM. pCO2 levels were 78 mmHg and 51 mmHg, respectively. In all experiments pCO2 was carefully maintained at a stable level. The pHi was measured by spectrofluorometry in BCECF-loaded PMphi exposed to different dialysis solutions or Hank's balanced salt solution. TNFalpha levels were measured by ELISA in the supernatant of lipopolysaccharide- (LPS) stimulated PMphi after their incubation in different solutions for 15 and 30 minutes. TNFalpha mRNA was measured by reverse transcriptase polymerase chain reaction (RT-PCR) of total RNA extracted from LPS-stimulated PMphi after their incubation in different solutions for 30 minutes. beta-actin mRNA was used as the control.
Dianeal caused a profound drop in pHi to below 6.2. Following an initial drop, pHi stabilized after 4 minutes at levels of 6.96 and 6.8 after incubation in TB and TBL, respectively. In comparison to the control solution, a fall of 11% and 21% in TNFalpha secretion was seen after incubation in TB for 15 and 30 minutes, respectively, and 15% and 26% after incubation in TBL. Under identical conditions, Dianeal (Baxter, McGaw Park, IL, U.S.A.) caused 59% and >95% suppression of TNFalpha secretion. Accordingly, TNFalpha mRNA level in PMphi was severely depressed by Dianeal but no detectable inhibition was observed following incubation for 30 minutes in TB and TBL. When dextrose concentration in TB and TBL was increased from 1.5% to 4.25%, TNFalpha secretion by PMphi was not suppressed by more than 49%, even after 30 minutes incubation. Moreover, suppression of TNFalpha mRNA levels could not be detected with TB or TBL even at high dextrose concentrations.
In contrast to Dianeal, both bicarbonate-based solutions caused only a mild drop in pHi of PMphi. We postulate this effect to be responsible for the improved capacity of PMphi to secrete TNFalpha when incubated in bicarbonate-based solutions compared to Dianeal. Reflecting its known cytotoxicity, dextrose in high concentrations diminishes the protective effect of TB and TBL on immune function of PMphi. TBL is as effective as TB in preventing the deleterious effect of Dianeal on PMphi function.
比较腹透液（Dianeal）与两种新配制的碳酸氢盐基腹膜透析液对细胞内pH值（pHi）、肿瘤坏死因子-α（TNFα）mRNA水平以及腹膜巨噬细胞（PMphi）分泌TNFα的影响。
从无腹膜炎的持续性非卧床腹膜透析患者过夜留腹后的透析液中分离腹膜巨噬细胞。透析液含1.5%或4.25%葡萄糖。碳酸氢盐缓冲液（TB）和碳酸氢盐/乳酸盐缓冲液（TBL）的HCO₃浓度分别为38 mM和25 mM。TBL还含有浓度为15 mM的乳酸盐。pCO₂水平分别为78 mmHg和51 mmHg。在所有实验中，pCO₂均被小心维持在稳定水平。通过荧光分光光度法在暴露于不同透析液或汉克平衡盐溶液的用BCECF负载的PMphi中测量pHi。在不同溶液中孵育15分钟和30分钟后，通过ELISA法测量脂多糖（LPS）刺激的PMphi上清液中的TNFα水平。在不同溶液中孵育30分钟后，通过对从LPS刺激的PMphi中提取的总RNA进行逆转录聚合酶链反应（RT-PCR）来测量TNFα mRNA。β-肌动蛋白mRNA用作对照。
腹透液使pHi大幅下降至6.2以下。在最初下降后，在TB和TBL中孵育4分钟后pHi分别稳定在6.96和6.8的水平。与对照溶液相比，在TB中孵育15分钟和30分钟后，TNFα分泌分别下降了11%和21%，在TBL中孵育后分别下降了15%和26%。在相同条件下，腹透液（美国伊利诺伊州麦加公园市百特公司生产）导致TNFα分泌抑制59%和>95%。因此腹透液严重抑制了PMphi中的TNFα mRNA水平，但在TB和TBL中孵育30分钟后未观察到可检测到的抑制作用。当TB和TBL中的葡萄糖浓度从1.5%增加到4.25%时，即使孵育30分钟，PMphi分泌的TNFα也未被抑制超过49%。此外，即使在高葡萄糖浓度下，用TB或TBL也未检测到TNFα mRNA水平的抑制。
与腹透液相比，两种碳酸氢盐基溶液仅使PMphi的pHi轻度下降。我们推测这种作用是与腹透液相比，在碳酸氢盐基溶液中孵育时PMphi分泌TNFα能力提高的原因。高浓度葡萄糖反映出其已知的细胞毒性，削弱了TB和TBL对PMphi免疫功能的保护作用。TBL在预防腹透液对PMphi功能的有害作用方面与TB一样有效。
