| Background and ObjectivePeritoneal dialysis (PD) is one of the effective ways for end-stage renal disease patients, who need accept renal replacement therapy to survive. Because peritoneal dialysis has its own advantages, such as a simple and convenient operation, no need to the establish vascular access, a small hemodynamic effect, a lower hepatitis C infection rate, better residual renal function protecting effect, etc., it has become the preferred alternative treatment for many ESRD patients. However, there was appeared peritoneal angiogenesis and increased permeability for a long-term PD patients. The reduction of ultrafiltration volume was reduced by peritoneal angiogenesis. Eventually ultrafiltration failure (UFF) would be occured. UFF was a major complication of long-term peritoneal dialysis. UFF has already become the major cause that PD patients dropped out. It also contributed to the death of PD patients. With the development of pathogenesis study on peritoneal dialysis ultrafiltration failure it was considered that peritoneal angiogenesis plays an important role in the mechanism of ultrafiltration failure. The main reason of UFF was peritoneal angiogenesis. Peritoneal histopathologic examination was done. Peritoneal angiogenesis was found on the peritoneum of PD patients who lost their ultrafiltration capacity. On the mechanism of angiogenesis, Hanahan proposed a popular hypothesis. It was the balance of the angiogenesis switch. It was considered that in the process of angiogenesis the proliferation and migration of vascular endothelial cells accepted a double regulating from inducers and inhibitors. Under normal circumstances the inducer and inhibitor of angiogenesis were in equilibrium. Once the balance was broken up, the quantity of inducers more than inhibitors', endothelial cells would be activated to promote neoangiogenesis. On the contrary, if the quantity of the inhibitors was more than inducers', then the growth of endothelial cells would be inhibited and the microvessels would be degradation. Basic fibroblast growth factor (bFGF) is one member of the fibroblast growth factor family. It received extensive attention. Because bFGF had wide distribution and strong capacity in promoting angiogenesis. bFGF was the most effective inducer of promoting angiogenesis in vivo. It was reported that, addition to its own capacity, bFGF and VEGF have cooperation in the process of promoting angiogenesis. Endostatin (ES) was a fragment of collagenâ…©â…§. ES was the strongest angiogenesis inhibitor and played the most specific role in inhibiting the course of blood vessel proliferation and migration. It showed that ES can specificly inhibite the proliferation of endothelial cells and thereby block the blood supply and nutrit to tumor cells. ES could supress the growth tumor and achieve the purpose of treatment. But whether it had the ability of inhibiting peritoneal angiogenesis was not clearly. CD34 and microvessel density were the ideal indicators to reflect the change of neoangiogenesis.On the basis of pre-theoretical and experimental study, we did the intervention study through the establishment of 5/6 nephrectomy uremic rats animal model. Then we established peritoneal dialysis rats model to imitat the peritoneal dialysis procedure of human. We selected bFGF and microvessel density detection as detection indexes. The treatment group rats were given recombinant human endostatin. By observing the expressions of bFGF and microvessel density in rats' peritoneum, we wanted to see the effect of recombinant human endostatin and look for the effective way to inhibite peritoneal angiogenesis. We preliminarily explored the potential mechanism of recombinant human endostatin inhibiting peritoneal angiogenesis. The aim was to maintain long-term and effective peritoneal dialysis for PD patients, prevent and treat peritoneal ultrafiltration failure, provide experimental basis for clinical treatment.Methods43 male SD rats of clean grade weighing 180-200g were used in the study. The uremia rats model was established by 5/6 nephrectomy and then from these uremia rats, we randomly established the peritoneal dialysis (PD) rats model. At last, there were 5 groups in this study: A:normal group (control group:n= 8), B:uremia group (5/6 nephrectomy group:n=8), C:uremia peritoneal dialysis group (4.25% dialysized group:n=8), D1:the first treatment group with recombinant human endostatin (10mg/kg treatment group:n=8), D2:the second treatment group with recombinant human endostatin (40mg/kg treatment group:n=8). The rats from C,D1,D2 groups were given regular peritoneal dialysis. The catheters implanted in dialysis rats were tunneled subcutaneously to the neck and exchanged PD solutions per rat were kept in the abdominal cavity for 2 hours per day without anesthesia. The rats from D1, D2 groups accepted subcutaneous injection of recombinant human endostatin during peritoneal dialysis period every other days, total administration 14 times. After regularly peritoneal dialysis for 28 days, tissue immunohistochemistry methods and reverse transcript polymerase chain reaction (RT-PCR) were applied to detect the mRNA and protein expressions of bFGF in rats'peritoneal tissues of each group. Microvessel density (MVD) of peritoneal tissue was assessed using immunohistochemistry with CD34 monoclonal antibody. Statistical analysis was performed to compare with their expressions and co relationship in each group. Significance was defined as a=0.05.Results1. Compared with the normal group, the mRNA and protein expression of bFGF were significantly up-regulated in uremia group and uremia peritoneal dialysis group(P<0.05). Compared with uremia peritoneal dialysis group, the mRNA and protein expression of bFGF were significantly down-regulated in the first and second treatment groups with recombinant human endostatin (P<0.05). Compared with the first treatment group with recombinant human endostatin, the mRNA and protein expression of bFGF were significantly down-regulated in the second treatment group with recombinant human endostatin (P<0.05).2. Compared with the normal group, MVD was up-regulated in uremia group and uremia peritoneal dialysis group (P<0.05). Compared with uremia peritoneal dialysis group, MVD was significantly down-regulated in the first and second treatment groups with recombinant human endostatin (P<0.05). Compared with the first treatment group with recombinant human endostatin, MVD was significantly down-regulated in the second treatment group with recombinant human endostatin (P<0.05).3. There was a positive correlation between bFGF and MVD in protein level.Conclusions1. The mRNA and protein level expression of bFGF might be up-regulated by uremic circumstance, high glucose and bioincompatible peritoneal dialysis liquid.2. The up-regulating of bFGF in peritoneal dialysis rats and patients peritoneum might participate in the increasement of the peritoneum neoangiogensis and then cause the incidence of ultrafiltration.3. Recombinant human endostatin can effectively inhibit peritoneum neoangiogensis inducing by peritoneal dialysis.4. Recombinant human endostatin can inhibit peritoneum neoangiogensis by down-regulating the expression of bFGF in peritoneam. |
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