Intraluminal thrombus enhances proteolysis in abdominal aortic aneurysms

This study examined whether intraluminal thrombus in abdominal aortic aneurysms (AAAs) is a source of fibrinolytic activity and proteolysis that could weaken the aneurysm wall. Plasmin, tissue plasminogen activator (tPA), and urokinase plasminogen activator (uPA) activity, plasminogen activator inhibitor 1 (PAI-1), and alpha2-antiplasmin (alpha2AP) antigen were measured in the AAA wall and juxtamural and luminal aspects of intraluminal thrombus in 18 patients. The aneurysm wall contained 100-fold higher tPA activity (1.06 +/- 0.34 [standard error of measurement] U/mg soluble protein) compared with juxtamural thrombus (JMT) (0.011 +/- 0.001 ) and luminal thrombus (LT) (0.01 +/- 0.001) (p < .00001) and over 6-fold higher uPA activity (29.3 +/- 3.4 IU/mg compared with the JMT (4.3 +/- 2.4, p = .00024) and LT (7.9 +/- 1.76, p = .0005). The LT had significantly lower levels of PAI-1 (1.26 +/- 0.34 ng/mg) than the AAA wall (2.08 +/- 0.51, p = .04) and the JMT (3.94 +/- 0.85, p = .007). The levels of alpha2AP in the wall (19.4 +/- 3.1 ng/mg) were lower than in the JMT or LT (43.0 +/- 7.9 ng/mg, p = .013, and 47.6 +/- 6.0 ng/mg, p = .002, respectively). There was no significant difference, however, in plasmin activity among the AAA wall, JMT, and LT. There were significant amounts of latent gelatinase B (matrix metalloproteinase [MMP]-9) in the AAA, JMT, and LT. Mean levels of activated MMP-9 activity were similar in the AAA, JMT, and LT. Plasmin activation of MMPs at the interface between intraluminal thrombus and the aneurysm wall may enhance proteolysis and accelerate aneurysm expansion.     

The role of the plasminogen system in bone resorption in vitro.

The plasminogen/plasmin proteolytic cascade plays an important role in extracellular matrix remodeling. The presence of the two plasminogen activators (PAs), tissue-type plasminogen activator (tPA), and urokinase-type plasminogen activator (uPA), and their inhibitor type 1 (PAI-1) in bone cells, suggests a role in one or more aspects of bone resorption such as osteoclast formation, mineral dissolution, and degradation of the organic matrix. These different processes were assayed in vitro using cells derived from mice with either tPA (tPA-/-), uPA (uPA-/-), PAI-1 (PAI-1-/-) inactivation or with a combined inactivation (tPA-/-:uPA-/-) and compared with wild-type mice (WT). First, osteoclast formation, assessed by investigating the number and characteristics of tartrate-resistant acid phosphatase-positive multinucleated cells formed in cocultures of primary osteoblasts and bone marrow cells treated with 1alpha,25-dihydroxyvitamin D3, was not different between the different cell types. Second, dentine resorption, an assay for osteoclast activity, was not affected by the combined deficiency of both tPA and uPA. Finally, the ability to degrade nonmineralized bone-like matrix was however, significantly reduced in tPA-/-:uPA-/- cells compared with WT cells (28.1 +/- 0.6%, n = 6 vs. 56.4 +/- 3.1%, n = 6, respectively, p < 0.0001). Surprisingly, collagen proteolysis by bone cells was not dependent on the presence of plasmin as suggested by degradation assays performed on type I 3H-collagen films. Taken together, these data suggest that the plasminogen activator/plasmin system is not required for osteoclast formation, nor for the resorption of the mineral phase, but is involved in the removal of noncollagenous proteins present in the nonmineralized bone matrix.     

Matrix metalloproteinase expressions in arteriosclerotic aneurysmal disease

Medial degeneration of extracellular matrix (ECM) proteins in the wall of abdominal aortas results in smooth muscle cell destruction, a loss of architectural integrity, and abdominal aortic aneurysm (AAA) formation. It has been theorized that an imbalance between proteinases and their naturally occurring inhibitors is the cause of these observed histologic abnormalities. Therefore, the purpose of this investigation was to determine if differences in the matrix metalloproteinase (MMP) -2 and -9, tissue inhibitor of metalloproteinase-1 (TIMP-1), tissue-type plasminogen activator (tPA), and urokinase-type plasminogen activator (uPA) protein and activity levels existed between infrarenal AAA and normal abdominal aortic tissue specimens. Between November 1995 and January 1997, 10 patients undergoing elective infrarenal AAA repair had a portion of their aneurysm walls snap frozen in liquid nitrogen and processed for subsequent western blot or zymographic analysis. Tissue specimens from 6 normal abdominal aortas obtained from fresh cadaver specimens were similarly processed and served as controls. Protein levels for MMP-2, MMP-9, TIMP-1, uPA, and tPA were analyzed by western blotting. The degree of MMP-2 and MMP-9 gelatinolytic activity was analyzed by zymography. Detection and immunolocalization for MMP-2, MMP-9 and CD68 was performed on tissue sections of AAA and normal infrarenal abdominal aortas fixed in 10% formalin. MMP-9 and tPA protein levels were increased in AAAs compared to controls by western blotting. However, uPA levels were slightly increased in controls. No differences in TIMP-1 protein levels were identified. Similarly, zymography demonstrated increased MMP-2 and MMP-9 gelatinolytic activity in AAAs compared to controls (p < or = 0.05). CD68-positive cells (macrophages) in the adventitia and media demonstrated immunoreactivity to MMP-9. This investigation demonstrated increased MMP-9 proteinase activity and tPA protein levels in the walls of AAAs, as well as inflammatory leukocyte invasion of the adventitia and media compared to controls. These data suggest that leukocyte-derived MMP-9 is associated with aortic wall degeneration and aneurysm formation. Furthermore, activation of MMP-9 may be caused by increased tPA levels in the walls of AAAs.     

Cellular localization of matrix metalloproteinases in the abdominal aortic aneurysm wall

Purpose: This study explores the source(s) of the matrix-degrading proteinases, matrix metalloproteinase 1 (MMP-1; interstitial collagenase), matrix metalloproteinase 3 (MMP-3; stromelysin 1), and matrix metalloproteinase 9 (MMP-9; gelatinase B), previously implicated in abdominal aortic aneurysm (AAA) development. The possible involvement of the plasmin cascade in the activation of these proteinases was also explored by examining the presence of the urokinase-type plasminogen activator (uPA) in aneurysm wall.Methods: Immunohistochemical techniques were used to detect the presence of MMP-1, MMP-3 and MMP-9 proteins and uPA in fixed, paraffin-embedded tissue sections from AAA (n = 10) and control (n = 2) aortas.Results: The MMP-9 protein was localized to mononuclear cells in the AAA wall. Dual-labeling techniques confirmed the identity of these cells as macrophages. The MMP-3 protein and uPA were also detected primarily in the macrophage-like mononuclear cells infiltrating the aneurysmal aorta. Immunoreactive material to MMP-1 was demonstrated in mesenchymal cells of the AAA wall suggesting alternative expression and delivery of this enzyme in AAA.Conclusions: This work establishes the role of macrophages in the delivery, expression, and possible activation of matrix destructive proteinases during AAA pathogenesis and suggests a role for the activation of MMPs in the progression of the disease. (J VASC SURG 1994;20:814-20.)     

Increased bone formation in mice lacking plasminogen activators.

Plasminogen activators tPA and uPA are involved in tissue remodeling, but their role in bone growth is undefined. Mice lacking tPA and uPA show increased bone formation and bone mass. The noncollagenous components of bone matrix are also increased, probably from defective degradation. This study underlines the importance of controlled bone matrix remodeling for normal endochondral ossification. INTRODUCTION: Proteolytic pathways are suggested to play a role in endochondral ossification. To elucidate the involvement of the plasminogen activators tPA and uPA in this process, we characterized the long bone phenotype in mice deficient in both tPA and uPA (tPA-/-:uPA-/-). MATERIALS AND METHODS: Bones of 2- to 7-day-old tPA-/-:uPA-/- and wild-type (WT) mice were studied using bone histomorphometry, electron microscopy analysis, and biochemical assessment of bone matrix components. Cell-mediated degradation of metabolically labeled bone matrix, osteoblast proliferation, and osteoblast differentiation, both at the gene and protein level, were studied in vitro using cells derived from both genotypes. RESULTS: Deficiency of the plasminogen activators led to elongation of the bones and to increased bone mass (25% more trabecular bone in the proximal tibial metaphysis), without altering the morphology of the growth plate. In addition, the composition of bone matrix was modified in plasminogen activator deficient mice, because an increased amount of proteoglycans (2x), osteocalcin (+45%), and fibronectin (+36%) was detected. Matrix degradation assays showed that plasminogen activators, by generating plasmin, participate in osteoblast-mediated degradation of the noncollagenous components of bone matrix. In addition, proliferation of primary osteoblasts derived from plasminogen activator-deficient mice was increased by 35%. Finally, osteoblast differentiation and formation of a mineralized bone matrix were enhanced in osteoblast cultures derived from tPA-/-:uPA-/- mice. CONCLUSIONS: The data presented indicate the importance of the plasminogen system in degradation of the noncollagenous components of bone matrix and suggest that the accumulation of these proteins in bone matrix--as occurs during plasminogen activator deficiency--may in turn stimulate osteoblast function, resulting in increased bone formation.     

Elevated tissue plasminogen activator in patients with screening-detected abdominal aortic aneurysm

OBJECTIVE: A population-based case-control study with historical and current data was conducted in a population with a high prevalence of disease to explore the hypothesis that the fibrinolytic system may be involved in the early pathogenesis of abdominal aortic aneurysm (AAA). METHODS: Forty-two patients found to have AAA at population-based screening were compared with 100 controls matched for age and sex. Mass concentration of tissue plasminogen activator (tPA mass) and tissue plasminogen activator/plasminogen activator inhibitor-1 complex (tPA/PAI-1 complex mass) were analyzed in blood samples obtained at the screening (current), and in blood samples obtained from a study conducted 12 years previously on the same population (historical). RESULTS: Current tPA mass levels were significantly higher in AAA patients compared with controls (13.6 vs 11.4 microg/L, P=.016). A similar trend was observed in historical tPA mass levels (9.8 vs 8.2 microg/L, P=.062). Current and historical mass concentrations of tPA/PAI complex in AAA patients were similar to those in controls. Current tPA mass levels retained the associations with AAA in a logistic regression model after adjustment for history of atherosclerosis (odds ratio [OR], 1.1 per microg/L, P=.039) and current smoking (OR 1.1 per microg/L, P=.039). When family history of AAA was added in a logistic regression model, the OR for current tPA mass was 1.1 per microg/L (P=.056) and 1.1 per microg/L (P=.070) when treated hypertension was added. CONCLUSION: The finding of elevated tPA mass, in contrast to tPA/PAI-1 complex, in plasma among patients with screening-detected AAA supports the hypothesis that the fibrinolytic system may be important in the early pathogenesis of AAA.     

Response of visceral peritoneum to abdominal surgery

BACKGROUND: Postoperative adhesion formation has been associated with a reduced capacity to degrade fibrin within the peritoneal cavity. Peritoneal fibrinolytic capacity has been shown to decrease during the course of a surgical operation. The aim of this study was to investigate whether tissue-type plasminogen activator (tPA), a key fibrinolytic enzyme, is released into the peritoneal cavity during operation. METHODS: Fluid released from the serosal surface of the small bowel was collected in a plastic bag from 16 patients undergoing surgery. Intraoperative blood samples were also taken from seven patients. Concentrations of the fibrinolytic components tPA and urokinase plasminogen activator (uPA), tPA activity and plasminogen activator inhibitor type 1 (PAI-1) concentration were measured by enzyme-linked immunoabsorbent assay. RESULTS: Intraoperative tPA concentrations were significantly raised in the peritoneal fluid collected compared with peripheral blood levels (P = 0.008). This resulted in a significantly higher tPA activity in the fluid compared with blood (P = 0.001). However, neither uPA (P = 0.29) nor PAI-1 (P = 0.84) concentrations differed significantly in fluid compared with blood. CONCLUSION: These data suggest that tPA is rapidly released by the visceral peritoneum during abdominal surgery. The different concentrations in peripheral blood and peritoneum suggest that tPA is released from the peritoneum by an active process, and does not solely derive from leakage of plasma.     

Effects of seprafilm on peritoneal fibrinolytic system

BACKGROUND: There is a high incidence of adhesions after ventral hernia repair with polypropylene mesh. The purpose of the present study was to evaluate the efficacy of Seprafilm in the prevention of adhesion formation and effect on peritoneal fibrinolytic activity. METHODS: An incisional hernia model was created in rats. In the experimental group Seprafilm was placed between polypropylene mesh and abdominal organs. On the 14th day adhesions were evaluated and tissue plasminogen activator (tPA), urokinase plasminogen activator (uPA), plasminogen activator inhibitor (PAI) type 1 and 2 were measured in peritoneal biopsy specimens. Results: Adhesions were significantly reduced in the Seprafilm group (P = 0.002). Nevertheless, there were no difference between the two groups in levels of tPA, PAI-1 and PAI-2. However, the levels of uPA were significantly decreased in the Seprafilm group. CONCLUSIONS: The adhesion preventive effect of Seprafilm is not directly related in peritoneal fibrinolytic activity. Instead, the physical properties (barrier, hydroflotation and sliconizing effect) of the membrane are primarily responsible for adhesion prevention.     

Peritoneal fibrinolytic activity in peritonitis

BACKGROUND: Peritonitis may cause a reduction in abdominal fibrinolytic activity. The reduced local fibrinolysis seems to be an important process in the subsequent development of adhesion formation. The aim of the study was to evaluate peritoneal fibrinolytic capacity in inflamed and normal peritoneum. METHODS: Peritoneal biopsy specimens were taken at the beginning of operation from 15 patients with peritonitis and 10 patients who underwent elective operation. Levels of tissue-type plasminogen activator (tPA), urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor (PAI) type 1 (PAI-1) and type 2 (PAI-2), and tPA/PAI complex in tissue extracts were determinated by commercially available enzyme-linked immunosorbent assay kits. RESULTS: tPA was significantly reduced in peritonitis compared with normal peritoneum (P <0.001), whereas it was found that the levels of PAI-1, PAI-2, uPA, and tPA/PAI complex in peritonitis were significantly higher than those in normal controls. CONCLUSIONS: Plasminogen activator activity was significantly reduced in peritoneal biopsy samples from patients with peritonitis compared with those from patients without peritonitis.     

Plasma levels of plasmin-antiplasmin-complexes are predictive for small abdominal aortic aneurysms expanding to operation-recommendable sizes.

OBJECTIVE: Three proteolytic systems seem involved in the aneurysmal degradation of the aortic wall. Plasmin is a common activator of the systems and could thus be predictive for the progression of abdominal aortic aneurysms (AAAs). METHODS AND MATERIALS: In 1994, 112 of 141 male patients with AAA diagnosed through population screening (defined as 3 cm or more) were interviewed and examined and had blood samples taken. One hundred twelve cases were scanned annually for 1 to 5 years (mean, 2.5 years) and referred for surgery if the AAA exceeded 5 cm in diameter. A random sample of 70 of the 112 cases had P-plasmin-antiplasmin-complexes (PAPs), P-plasminogen, and S-elastin-peptides (SEPs). RESULTS: PAP was positively correlated with annual expansion rate (r = 0.39, 0.16-0.56), persisting after adjustment for initial AAA size, SEP, age, and smoking. However, PAP levels did not correlate with the initial AAA size or SEP. Furthermore, PAP levels were significantly predictive for cases expanding to operation-recommendable AAA sizes. Combined with the initial AAA size, both optimal sensitivity and specificity were 82%, increasing to 95% and 96%, respectively, excluding those lost to follow-up and accepting 2 mm of interobserver variation. CONCLUSION: The progression of AAA is correlated with the PAP level, which seems to have a predictive value similar to the best serologic predictor known, serum-elastin-peptides.     

7/8肾切除大鼠凝血纤溶系统的变化及干预治疗的影响

目的：探讨肾小球硬化及小管间质纤维化过程中肾组织纤溶酶原激活物（PA）和PA抑制物（PAI）－1蛋白表达及干预治疗的影响。方法：7／8肾切除肾功能衰竭大鼠为实验动物模型,随机分为未治疗组和治疗组,观察12周后各组大鼠血尿各项生化指标、尿PA活性及残肾组织常规病理和用免疫组织化学染色定性定量评价残肾组织型PA（tPA)、尿激酶型（uPA)、PAI－1蛋白表达。结果：未治疗组大鼠肾功能进行性丧失,尿PA活性下降,肾组织PAI－1表达增高,而tPA、uPA表达下降,残肾组织出现肾小球硬化和间质纤维化。治疗组大鼠残肾组织tPA、uPA蛋白表达增加,PAI－1表达下降。尿PA活性增加,肾功能改善。结论：水蛭治疗组、苯那普利治疗组及联合治疗组都可以通过改善7／8肾切除大鼠PA／PAI－1系统的紊乱而延缓肾小球硬化和间质纤维化病变的进展。     

Plasminogen activator levels are influenced by location and varicosity in greater saphenous vein

Purpose: The plasminogen system, which includes tissue type plasminogen activator (tPA), urokinase type plasminogen activator (uPA), and their main inhibitor, plasminogen activator inhibitor type 1 (PAI-1), plays a major role in both fibrinolysis and tissue remodeling. This study compares the levels of tPA, uPA, and PAI-1 at the groin and ankle in normal and varicose greater saphenous vein (GSV).Methods: GSV was collected from patients undergoing varicose vein (VV) removal and from normal vein (NV) from arterial bypass procedures. Portions of the GSV at the groin and the ankle were minced and placed in serum-free media for 48 hours. Assays of the supernatants were obtained for tPA, uPA, and PAI-1 protein by enzyme-linked immunosorbent assay. Cyclohexamide and actinomycin D were also added to the media of the VV tissue explant supernatants to inhibit protein and RNA synthesis, respectively.Results: Levels of tPA were significantly higher at the groin (11 ± 2) than the ankle (5 ± 1) in the VV ( p < 0.005), and this trend was also seen in the NV (groin 10 ± 2 and ankle 7 ± 3). Levels of uPA were significantly higher in the groin VV (14 ± 4.3) than in NV (3.0 ± 0.8, p < 0.05). This difference, although not statistically significant, applied to the ankle as well (VV 14.5 ± 6.3 and NV 5.3 ± 2.7). No significant difference was seen between NV and VV for PAI-1 (NV, groin 155 ± 73 and ankle 113 ± 53, VV, groin 161 ± 20 and ankle 142 ± 38) or tPA. Inhibitor studies revealed no significant difference among control, cyclohexamide, and actinomycin D supernatants for tPA, suggesting release of protein rather than active synthesis. In contrast, inhibitor supernatants were significantly lower for uPA and PAI-1 than control supernatants ( p < 0.05), suggesting that uPA and PAI-1 were actively synthesized.Conclusions: In the tissue explant supernatant model uPA and PAI-1 are actively synthesized, but tPA is not. Levels of PAI-1 were comparable in all four groups. Levels of uPA in the varicose GSV were higher than in NV, suggesting a role for uPA in the pathologic makeup of VV. Levels of tPA were higher at the groin versus the ankle position, potentially explaining the previously described increased fibrinolytic activity seen at the groin. (J Vasc Surg 1996;24:719-24.)     

Cyclooxygenase-2 alters transforming growth factor-beta 1 response during intestinal tumorigenesis.

BACKGROUND: Recent investigation suggests that cyclooxygenase-2 plays an important role in colorectal carcinogenesis. Transforming growth factor-beta1 (TGF-beta 1) is one of the most potent stimulators of cyclooxygenase-2 expression. A key step in intestinal tumorigenesis involves alteration of the normal cellular response to TGF-beta 1. We have hypothesized that overexpression of cyclooxygenase-2 alters intestinal epithelial response to TGF-beta 1. METHODS: RIE-1 cells were stably transfected with rat cyclooxygenase-2 complementary DNA in either the sense (RIE-S) or antisense (RIE-AS) orientation. Tumor cell invasion was assessed with a modified Boyden collagen type I invasion assay in the presence of TGF-beta 1, antibody to urokinase plasminogen activator (uPA), or the selective cyclooxygenase-2 inhibitor SC-58125. Expression of uPA, uPA receptor, and plasminogen activator inhibitor-1 were determined by Western blot and enzyme-linked immunosorbent assay. RESULTS: RIE-1 and RIE-AS did not invade although RIE-S cells were minimally invasive at baseline. TGF-beta 1 had no effect on RIE-1 or RIE-AS invasion; however, TGF-beta 1 significantly upregulated RIE-S cell invasion. All 3 RIE cell lines produce minimal uPA under basal conditions. TGF-beta 1 upregulated uPA production only in the RIE-S cells. Both antibody to uPA and SC-58125 reversed TGF-beta-mediated RIE-S cell invasion. SC-58125 inhibited TGF-beta-mediated RIE-S uPA production. CONCLUSIONS: These results demonstrate that overexpression of cyclooxygenase-2 alters intestinal epithelial response to TGF-beta 1, which may be a mechanism by which cyclooxygenase-2 promotes colon carcinogenesis.     

Effect of shear stress on the expression of coagulation and fibrinolytic factors in both smooth muscle and endothelial cells in a co-culture model

Blood vessels are subjected to forces due to the flow. Endothelial cells (EC) are recipients, cross-talk with smooth muscle cells (SMC), and regulate physiology. It was hypothesized that both EC and SMC respond to shear stress, which alters the expression of factors in coagulation and fibrinolysis. METHODS: A co-culture of human saphenous vein EC (HSVEC) and human saphenous vein SMC (HSVSMC) was exposed to shear, following which the cells were separated. Gene expression of tissue factor, thrombomodulin (TM), plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (tPA) and urokinase plasminogen activator (uPA) were analyzed with real-time RT-PCR. Protein expression was studied with ELISA. In HSVEC, the expression of PAI-1 (x2.1), tPA (x1.8), uPA (x1.6), tissue factor (x2.5) and TM (x1.9) was upregulated after 4 h of shear compared to controls. After 24 h of shear, expression was still upregulated in tPA (x2.3) and TM (x1.6). In HSVSMC, change in expression of PAI-1 (x2.1) was present after 4 h and in uPA (x2.1), and TM (x0.4) after 24 h. Both HSVEC and HSVSMC responded to shear, which led to altered expression of coagulation and fibrinolytic factors. This indicates that SMC, and interactions between EC and SMC, are more important in the regulation of vascular wall hemostasis than earlier studies have reported.     

Abdominal aortic aneurysm and aortic occlusive disease: a comparison of risk factors and inflammatory response.

OBJECTIVE: to compare patients with abdominal aortic aneurysm (AAA) and aortic occlusive disease (AOD) with regard to risk factors for atherosclerosis, co-morbid conditions and inflammatory activity. PATIENTS AND METHODS: a total of 155 patients undergoing abdominal aortic surgery between January 1993 and October 1997: 82 (53%) had aneurysmal disease and 73 (47%) had occlusive disease. Principal risk factors were compared: age; gender; smoking; hypertension; hyperlipidaemia; diabetes mellitus; severe peripheral vascular disease (PVD) and ischaemic heart disease. Aortic wall tissue samples were obtained during surgery. A prospective blind analysis was performed for the presence of inflammatory cytokines TNF-alpha, IL-1 beta, IL-6 and TGF-beta. RESULTS: the average age of AAA patients was 74 years (50-88), while that of AOD patients was 61 years (43-82) (p<0.0001). Diabetes mellitus was found to be much more prevalent in the AOD group (p<0.001), while hypertension and severe PVD were more prevalent in the AAA group (p<0.001). No differences were found concerning any of the risk factors. Inflammatory cytokine activity: AAA tissue samples contained significantly higher mean TNF-alpha and IL-6 levels compared to the AOD samples (5.6+/-2.7 x 10 E-4 vs. 4.4+/-2.7 x 10 E-5 atmoles/microl (p=0. 01), and 0.6+/-0.4 vs. 0.01+/-0.006 atmoles/microl (p=0.02) respectively). No differences were found related to IL-1 beta and TGF-beta. CONCLUSIONS: (1) Patients with AAA have fewer atherosclerotic risk factors than do patients with AOD. (2) Patients with AAA and AOD have significantly different inflammatory activity. (3) The data supports the hypothesis that AAA and AOD are probably two different pathological entities.     

Prevention of intraperitoneal adhesions and abscesses by polysaccharides isolated from Phellinus spp in a rat peritonitis model

OBJECTIVE: To assess whether polysaccharides isolated from fungi, Phellinus spp, could reduce the adhesion and abscess formation in a rat peritonitis model. SUMMARY BACKGROUND DATA: Although polysaccharides from Phellinus spp is a well-known material with antiinflammatory properties, little is known regarding its ability to prevent intraperitoneal adhesions. We have assessed the adhesion- and abscess-reducing effect of polysaccharides from Phellinus gilvus (PG) and Phellinus linteus (PL) in a rat peritonitis model. METHODS: In 60 SD rats, experimental peritonitis was induced using the cecal ligation and puncture model (CLP). Animals were randomly assigned to 5 groups; ringer lactate solution (RL group), polysaccharides from PG and PL (PG and PL group), hyaluronic acid (HA group), and carboxymethylcellulose (CMC group). Intraperitoneal adhesions and abscesses were noted at 7 day after CLP. RT-PCR assay for urokinase-type plasminogen activator (uPA), its cellular receptor (uPAR), tissue-type plasminogen activator (tPA), plasminogen activator inhibitor type 1 (PAI-1), and tumor necrosis factor (TNF)- alpha was performed to assess the cecal tissue. RESULTS: Adhesion formation was significantly reduced in PG, PL, CMC, and HA groups (P < 0.001) compared with that in RL group. The incidence of abscesses was also significantly reduced in PG and PL groups (P < 0.05) compared with that in the RL group. The level of uPA, uPAR, tPA, and TNF-alpha was highly expressed in PG and PL group, as compared with the RL group. CONCLUSIONS: We concluded that PG and PL had significant adhesion- and abscess-reducing effects and may act by modulating fibrinolytic capacity of uPA and/or tPA produced from macrophages in a rat peritonitis model.     

纤维蛋白对肾小球内皮细胞表达纤溶酶原激活物及纤溶酶原激活物抑制物的作用

目的：观察体外培养人肾小球内皮细胞（GEC）表面原位形成的纤维蛋白对GEC表达纤溶酶原激活物及纤溶酶原激活物抑制物（PA／PAI）的影响。方法：应用逆转录聚合酶链反应（RT－PCR）,酶谱分析法与反向酶谱法分别在基因转录水平与蛋白质活性水平上检测纤维蛋白对GEC表达tPA,uPA gn PAI-1r 作用,纤维蛋白平板法检测纤维蛋白对GEC PA／PAI系统的综合效应,结果：纤维蛋白能够明显促进tPA,uPA与PAI－1的mRNA表达上调,无血清RPMI 1640培养下的GEC几乎检测不到PAI知性,但可检测到PAI－1的活性。纤维蛋白能够浓度依赖性刺激GEC tPA与uPA活性增加以及PAI01的活性增加,呈浓度依赖性与时间依赖性,相同剂量的纤维蛋白原与纤维蛋白的作用相似,放线菌酮与放线菌素D均可抑制纤维蛋白上调GEC表达tPA,uPA与PAI的作用,纤维蛋白平板法显示,纤维蛋白对GEC PA／PAI系统的综合效应是以升高PA活性为主,其活性能够被抑肽酶完全阻断。结论：肾脏局部毛细血[管内沉积的纤维蛋白可能通过对GEC PA／PAI系统的调节发挥其病理作用。