Multidirectional approach to study peritoneal dialysis fluid biocompatibility in a chronic peritoneal dialysis model in the rat.

BACKGROUND: Peritoneal dialysis causes the functional and morphological changes in the peritoneum that result from the bioincompatibility of dialysis solutions. We present a model of chronic peritoneal dialysis in the rat that can be used for testing the biocompatibility of dialysis fluids. Methods and Results. Long-term exposure of the peritoneum to dialysis solutions can be performed in rats with implanted peritoneal catheters. Sampling of the dialysate allows the evaluation of intraperitoneal inflammation by examining cell differential and dialysate cytokine levels. Peritoneal permeability can be evaluated at designed time intervals with the peritoneal equilibration test (PET). At the end of dialysis, peritoneal histology is studied with light and electron microscopy. CONCLUSIONS: Such a multidirectional approach is an effective way to test biocompatibility of dialysis solutions.     

Inhibition of Rho-kinase alleviates peritoneal fibrosis and angiogenesis in a rat model of peritoneal dialysis

Abstract

Background/Aims: The present study investigated whether Rho-kinase inhibition had a therapeutic role on the pathogenesis of peritoneal fibrosis and angiogenesis. Methods: A rat model of peritoneal dialysis was induced by a daily intraperitoneal infusion of 4.25% Dianeal. Those rats were treated with Rho-kinase inhibitor, fasudil. Immunofluorescence, Western blot and RT-PCR were used to detect the expression of TGF-β1, Collagen I, αSMA and VEGF in each group. Microvessel density (MVD) was measured by immunohistochemistry. Rho-kinase activity was determined by western immunoblotting. Results: Rho-kinase was activated in the peritoneum of the PD group, which was inhibited by fasudil. Compared with PD group, the mRNA and protein expressions of TGF-β1, αSMA and Collagen I were significantly downregulated in fasudil treatment groups in a dose-dependent manner, and the expression of VEGF and peritoneal MVD was also significantly downregulated in fasudil treatment groups in a dose-dependent manner. Conclusion: The Rho-kinase was activated in the peritoneum of the peritoneal dialysis rats, and the inhibition of Rho-kinase by fasudil can remarkably decrease peritoneal fibrosis and angiogenesis.     

Immunopathological changes in a uraemic rat model for peritoneal dialysis.

BACKGROUND: Peritoneal dialysis (PD) is a treatment modality for patients with renal failure. Both the uraemic state of these patients and chronic exposure to PD fluid are associated with the development of functional and structural alterations of the peritoneal membrane. In a well-established chronic PD rat model, we compared rats with normal renal function with subtotal nephrectomized rats that developed uraemia. METHODS: Uraemic and control rats received daily 10 ml conventional glucose containing PD fluid, via peritoneal catheters during a 6 week period. Uraemic and control rats receiving no PD fluid served as controls. Parameters relevant for peritoneal defence and serosal healing responses were analyzed. RESULTS: Uraemic animals were characterized by 2-3-fold increased serum urea and creatinine levels, accompanied by a significantly reduced haematocrit. Uraemia (without PD fluid exposure) induced new blood vessels in different peritoneal tissues, accompanied by increased accumulation of advanced glycation end products (AGEs) and elevated levels of angiogenic factors such as vascular endothelial growth factor and monocyte chemoattractant protein-1 (MCP-1) in peritoneal lavage fluid. A much stronger peritoneal response was observed upon PD fluid exposure in non-uraemic rats. This included the induction of angiogenesis and fibrosis in various peritoneal tissues, accumulation of AGEs, immunological activation of the omentum, damage to the mesothelial cell layer, focal formation of granulation tissues and increased MCP-1 and hyaluronan levels in peritoneal lavage fluid. Finally, chronic PD fluid instillation in uraemic rats did not induce an additional peritoneal response compared to PD fluid exposure in non-uraemic rats, except for the degree of AGE accumulation. CONCLUSIONS: Both uraemia and PD fluid exposure result in pathological alterations of the peritoneum. However, uraemia did not induce major additive effects to PD fluid-induced injury. These results substantially contribute to the understanding of the pathobiology of the peritoneum under PD conditions.     

Cellular response to peritonitis among peritoneal dialysis patients

White blood cell counts and differential cell counts were performed on 249 peritoneal dialysis effluents from 48 patients using chronic peritoneal dialysis. The finding of more than 50% polymorphonuclear leukocytes in the dialysate was a more sensitive indicator of peritonitis than was an absolute cell count of 100 cells/microL. This finding was true for patients using intermittent peritoneal dialysis, continuous ambulatory peritoneal dialysis, and continuous cycling peritoneal dialysis.     

Role of rosiglitazone in lipopolysaccharide-induced peritonitis: A rat peritoneal dialysis model

Aim: The aim of this study was to demonstrate the efficacy of the peroxisome proliferator‐activated receptor (PPAR)‐γ agonist, rosiglitazone, in the amelioration or prevention of inflammation including peritoneal fibrosis secondary to the peritonitis in a peritoneal dialysis (PD) model of non‐uraemic rats. Methods: Thirty male Sprague–Dawley rats were assigned to six groups according to treatment. A 90 min peritoneal equilibrium test, dialysate cellular components, peritoneal thickness and cellularity were assessed on day 21. Additionally, immunohistochemical stains of peritoneal membrane, such as PPAR‐γ, vascular endothelial growth factor (VEGF), transforming growth factor (TGF)‐β1, collagen‐1 and monocyte chemoattractant protein‐1 were performed Results: The dialysate neutrophil count and peritoneal thickness in the high‐dose rosiglitazone group was significantly decreased compared to the lipopolysaccharide (LPS)‐only group. The peritoneal membrane from the LPS‐only group showed marked cellular proliferation in the area of the submesothelial compact zone compared with the PD‐only group, the rosiglitazone‐only group, and the high‐dose rosiglitazone group. The 90 min peritoneal equilibrium test (PET) results showed no statistical difference among the six groups excluding dialysate‐to‐plasma urea ratio. The number of PPAR‐γ expressing cells and the expression of TGF‐β1 were decreased in the high‐dose rosiglitazone group compared to the LPS‐only group. There were no differences in the expression of VEGF and collagen‐1 among the six groups. Interestingly, the number of PPAR‐γ‐positive cells was correlated with expression of VEGF, TGF‐β1, collagen‐1 and monocyte chemoattractant protein‐1 irrespective of the study group. Conclusion: The results of this study showed that rosiglitazone ameliorated peritoneal inflammation induced by LPS and reduced the TGF‐β1 expression in the peritoneal membranes.     

地塞米松在防治腹膜通透性增高中的作用

目的探讨腹膜透析过程中地塞米松对腹膜表面层、间皮细胞形态和腹膜功能的影响.方法24只SD雄性大鼠随机分为4组.第1组大鼠不接受任何注射即行腹膜动力学实验;第2组以4.25%的高糖透析液透析;第3组(地米1组)腹腔内注射4.25%的透析液并加入地塞米松(剂量为0.1 mg/kg),每天1次,连续7d;第4组(地米2组)腹腔内连续注射透析液2周,第1周为普通4.25%透析液,第2周始用上述剂量地塞米松的透析液继续透析1周.以上各组在停止透析48 h后行腹膜动力学实验.然后取前腹壁组织行光镜及电镜检查.结果腹腔注射4.25%的透析液7 d后,腹膜功能呈高通透性,腹膜表面层明显变薄及疏松,腹膜组织呈明显慢性纤维化改变.使用了加入地塞米松透析液的两组动物其腹膜表面层、间皮细胞形态和腹膜功能与对照组比较无显著差异.结论腹腔注射地塞米松对腹膜表面层、间皮细胞形态有很好的保护作用,明显改善大鼠高通透腹膜的转运功能.     

腹膜透析对急性重症胰腺炎大鼠胰腺微循环的影响

目的：探讨腹膜透析（PD）对急性重症胰腺炎（ASP）大鼠胰腺微循环的影响。方法：SD大鼠72只随机分为对照组（24只）、ASP组（24只）和ASP加PD组（24只）；观察各组血清血栓素A2／前列腺素（TXA2／6-K．PGF1a）和内皮素（ET—1）水平，以及胰腺血流波幅和胰腺病理变化。结果：ASP组和PD组血清ET-1水平较对照组明显升高；在同时段病例中，ASP组与加PD组比较，后者的水平明显降低；ASP组和加PD组血清TXA2／6-K—PGF1a水平较对照组明显升高：同时段ASP组与加PD组比较，后者的水平明显降低。ASP组胰腺血流波幅明显降低，加PD治疗后波幅有显著提高。加PD组大鼠的胰腺病理损害较ASP组明显减轻。结论：微循环障碍是ASP的重要病理生理基础．早期行PD治疗能有效地改善ASP所致之血微循环障碍，对胰腺有保护作用。     

Pharmacological inhibition of heparin-binding EGF-like growth factor promotes peritoneal angiogenesis in a peritoneal dialysis rat model

Background

Molecular mechanisms of peritoneal dialysis (PD) ultrafiltration failure, peritoneal neo-angiogenesis, and fibrosis remain to be determined. We aimed to determine the role of heparin-binding EGF-like growth factor (HB-EGF) inhibition on angiogenesis of peritoneal membrane in a PD rat model.

Methods

32 male Wistar rats were assigned into (1) control group; (2) uremic non-PD group: subtotal nephrectomy-induced uremic rats without PD; (3) uremic rats subjected to PD: uremic rats that were dialyzed with Dianeal^® for 4 weeks; (4) CRM 197 group: dialyzed uremic rats were supplemented with CRM197, a specific HB-EGF inhibitor. Peritoneal transport function was examined by peritoneal equilibration test. Expression of HB-EGF and EGFR in peritoneal samples were examined by real-time PCR, immunohistochemical staining, and western blot.

Results

Progressive angiogenesis and fibrosis were observed in uremic PD rats, and there were associated with decreased net ultrafiltration (nUF), increased permeability of peritoneal membrane, and reduced expression of HB-EGF and EGFR protein and mRNA in uremic PD rats compared to uremic non-PD or control groups (both p < 0.05). CRM197 significantly induced peritoneal membrane permeability, decreased nUF, increased higher vessel density, and reduced pericyte count compared to that of uremic PD rats. The levels of HB-EGF and EGFR expression negatively correlated with vessel density in peritoneal membrane (both p < 0.001).

Conclusion

PD therapy was associated with peritoneal angiogenesis, functional deterioration, and downregulation of HB-EGF/EGFR. Pharmacological inhibition of HB-EGF promoted PD-induced peritoneal angiogenesis and fibrosis and ultrafiltration decline, suggesting that HB-EGF downregulation contributes to peritoneal functional deterioration in the uremic PD rat model.

     

MiR-200a ameliorates peritoneal fibrosis and functional deterioration in a rat model of peritoneal dialysis

International Urology and Nephrology - Peritoneal fibrosis is recognised as the main cause of the technical failure of peritoneal dialysis (PD), and currently, there are no specific and effective...     

Peritoneal infection in acute intermittent peritoneal dialysis

A prospective study was done to evaluate the incidence and microbiological trend of peritoneal infection in patients undergoing acute intermittent peritoneal dialysis (PD). Complete sterile procedure was ensured and at the completion of the procedure PD fluid was sent for bacteriological culture, sensitivity, and total and differential cell count. During the period September 2000 to February 2001 a total of 100 patients were evaluated. Male female ratio was 72:28. Mean age was 43.17 +/- 17.2 years. In 26 patients cyclers were used. Bacterial culture was positive in total of 30 cases (30%). Gram positive, Gram negative and mixed infection was found in 10%, 15%, and 5% respectively. Number of exchanges (31.61 +/- 7.7 vs. 31.3 +/- 6, p = 0.8) were similar and number of repositioning was significantly more in the infected group (23.3% vs. 11.4%, p < 0.01). Total cell count was significantly higher in infected group (274.3 +/- 502 vs. 31.25 +/- 79.34, p < 0.01). Among Gram +ve organisms Staphylococcus was found in 7, Enterococcus faecalis in 4 and Coryne bacterium sps. in 2 cases. Among Gram -ve organisms, E. coli was found in 4, Enterobacter in 3, Klebsiella 1, Pseudomonas 1, Acinetobacter arinatus 5, Acinetobacter baumani 3, and Citrobacter freundii 3. Mixed flora comprised of Enterococcus faecalis 3, Enterobacter 1, Staphlococcus 1, E. coli 3, Citrobacter 1, Acinobacter baumani 1. Although with the cyclers using collapsible bags, staphylococcus was not isolated, the total incidence of infection (11/26 cases) was not decreased with the use of cyclers. We conclude that in acute intermittent peritoneal dialysis the incidence of bacterial infection is 30% with preponderance of Gram -ve over Gram +ve organisms and organism of fecal origin being commoner than those of skin origin. Use of cycler-assisted over manual PD do not improve the incidence of infection. Repositioning of the stiff catheter significantly increases the incidence of infection.     

Ultrafiltration and effective peritoneal blood flow during peritoneal dialysis in the rat

The dependence between maximum net ultrafiltration rate (nUFR) created by 15% dextrose dialysis solution and effective peritoneal capillary blood flow (EPBF) estimated by the diffusive mass transport coefficient (KBD) and peritoneal clearance (Cp) of CO2 gas was evaluated during 30 minute, 15 ml peritoneal dialysis exchanges in anesthetized rats (N = 18). The values of KBD for CO2 suggested a mean EPBF of 1.9 +/- 0.1 (SEM) ml/min for isosmotic exchanges and 2.7 +/- 0.2 ml/min for hyperosmotic ones with a mean maximum nUFR of 0.43 +/- 0.01 ml/min. Cp of CO2 measured after the first five minutes of dwell underestimated EPBF. In normally hydrated rats, maximum nUFR was achieved when the peritoneal filtration fraction was 32 +/- 2%. This value is similar to the glomerular filtration fraction in rats of 30%. Thus, our results indicate the following relationships: EPBF = (approximately 3 x maximum nUFR)/(1 - hematocrit). EPBF was about six times greater than maximum nUFR and exceeded about 57 times nUFR obtained under isosmotic conditions. These differences between EPBF and nUFR suggest normal EPBF is not a major limiting factor for maximum ultrafiltration achieved during peritoneal dialysis.     

腹膜透析对重症急性胰腺炎大鼠肾损害的保护作用

目的探讨腹膜透析(PD)对重症急性胰腺炎(SAP)大鼠肾损害的保护作用并探讨可能的机制。方法SD大鼠72只随机分为对照组(24只)、SAP组(24只)和PD组(24只),观察各组血清前列腺素(TXA2/6-K-PGF1a)及内皮素(ET-1)水平和肾脏病理变化。结果SAP组和PD组血清ET-1水平较对照组明显升高,同时段SAP组与PD组比较,PD组水平明显降低;SAP组和PD组血清TXA2/6-K-PGF1a水平较对照组明显升高,同时段SAP组与PD组比较,PD组水平明显降低。PD组大鼠肾病理损害较SAP组明显减轻。结论血液流变异常参与SAP肾损害的发生,早期进行PD治疗对SAP大鼠肾有保护作用,其可能的机制是改善微循环、清除炎症介质等。     

腹膜透析对水通道蛋白3在大鼠腹膜组织表达的影响

腹膜超滤衰竭(UFF)是长期腹膜透析的主要并发症,腹膜水转运特性发生改变将会导致超滤衰竭的发生.有报道称水通道蛋白家族成员之一AQP3不仅选择性通透水,而且高通透甘油和尿素,在腹膜溶质转运方面发挥着重要的作用.     

腹膜透析在急性肾损伤中的应用

急性肾损伤(AKI)是临床常见急危重症之一。肾脏替代治疗是挽救AKI患者生命的重要救治措施。腹膜透析具有简单易行、无需特殊设备、无需抗凝、对血流动力学影响小等优势。腹膜透析已被国际腹膜透析学会(ISPD)指南推荐作为AKI治疗理想的肾脏替代方式之一。     

Video-assisted thoracoscopic talc pleurodesis is effective for maintenance of peritoneal dialysis in acute hydrothorax complicating peritoneal dialysis.

BACKGROUND: Acute, massive, unilateral hydrothorax is an uncommon but well-recognized complication of peritoneal dialysis. Its clinical course and treatment outcome after a recently advocated technique of video-assisted thoracoscopic (VATS) talc pleurodesis remains unclear. METHODS AND RESULTS: Between July 1998 and March 2002, among 475 CAPD patients in two regional hospitals in Hong Kong, nine patients (three men, six women, mean age 53+/-12 years) developed acute hydrothorax due to pleuroperitoneal communication (R=8, L=1) within 5.8+/-4.2 months (median, 5.2 m; range, 2 days to 11.6 months) of commencing peritoneal dialysis. Analysis of simultaneously obtained peritoneal and pleural fluid in all subjects only showed concordance in protein content (consistently<4 g/l), while fluid glucose and lactate dehydrogenase levels were not comparable. The methylene blue test was negative (n=4). Radionuclide scan (n=6) and contrast CT peritoneography (CTP, n=3) detected pleuroperitoneal communication in half and one-third of the patients, respectively. All patients underwent pleurodesis achieved by talc insufflation into the pleural cavity under VATS guidance. All patients were successfully returned to peritoneal dialysis. After a mean follow-up of 18.8+/-12.5 months, hydrothorax recurred in one patient (at 7 months after pleurodesis), who was successfully treated by repeating the procedure. CONCLUSIONS: Hydrothorax complicating CAPD is more commonly right-sided, and tends to occur within the first year of starting peritoneal dialysis. Isotope scan and CTP are insensitive in diagnosing pleuroperitoneal communication. A low pleural fluid protein content is the most consistent biochemical finding. VATS talc pleurodesis is a safe and reliable treatment of choice that allows sustained continuation of CAPD with low recurrence rate.     

胃穿孔引发腹膜透析患者急性腹膜炎

患者,男,80岁,腹膜透析4年.1周前患者无诱因腹痛,腹透引流液浑浊,腹透液常规白细胞总数1500/mm3,多核细胞0.85,诊断为腹膜炎,予头孢唑啉及头孢他啶各1 g/d入腹透液治疗.     

Evaluation of peritoneal dialysis solutions with amino acids and glycerol in a rat model.

In this study a simple rat model for evaluating the ultrafiltration by peritoneal dialysis solutions is described. Anaesthetised male Sprague-Dawley rats were injected intraperitoneally with dialysis solutions. Zero, 1, 3, or 6 h later, the dialysate volume was determined directly: the abdomen was carefully opened, the intraperitoneal liquid was withdrawn with a syringe and its volume was measured. Good recovery of dialysate, highly reproducible results, and the similarity between the ultrafiltration profiles in rats and published profiles in CAPD patients for control solutions, indicate that the model is valid. The model was then used to evaluate peritoneal dialysis solutions containing a mixture of glycerol and amino acids. Both osmotic agents are chemically compatible and these mixtures provide amino acids and carbohydrates in a single solution. For three mixtures, intraperitoneal dialysate volume were determined as a function of dwell time and the formulation with the desired ultrafiltration could be selected.