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The protein kinase C (PKC) superfamily comprises proteins that are activated in response to various pathogenic stimuli in the diabetic state. Hyperglycaemia is the predominant stimulus that induces the activation of distinct PKC isoforms within a cell, each mediating specific functions, probably through differential subcellular localisation. The contribution of individual PKC isoforms can be directly addressed in vivo using innovative PKC-isoform-specific knockout (KO) mouse models, which are providing key insights into the physiological function of PKC isoform diversity in the development of diabetic nephropathy. Such studies can be a valuable complementary approach to more commonly used pharmacological analyses using agents such as ruboxistaurin mesylate (Arxxant, LY333531), which is claimed to specifically inhibit the PKC-beta-isoform. As expected given the multiple and specific properties of the isoforms in vitro, deletion of different PKC isoform signalling pathways leads to distinct phenotypes in mice. Notably, KOs of the individual PKCs assigned specific non-redundant biological functions to each isoform, which were not compensated for by the others. Thus, PKC isoform specificity and cellular diversity seem to be responsible for the divergent outcomes leading to albuminuria and/or renal fibrosis according to studies on the streptozotocin-induced mouse model of diabetes. This review discusses the role of individual PKC isoforms in diabetic nephropathy and their potential therapeutic implications. Defining and targeting mediators of increased intracellular activation in the diabetic microvasculature will have important clinical and therapeutic benefits and help in the design of novel effective therapies in the near future.

Complement activation plays a key role in mediating apoptosis, inflammation, and transplant rejection. In this study, the role of the complement 5a receptor (C5aR) was examined in human renal allografts and in an allogenic mouse model of renal transplant rejection. In human kidney transplants with acute rejection, C5aR expression was increased in renal tissue and in cells infiltrating the tubulointerstitium. Similar findings were observed in mice. When recipient mice were treated once daily with a C5aR antagonist before transplantation, long-term renal allograft survival was markedly improved compared with vehicle-treatment (75 versus 0%), and apoptosis was reduced. Furthermore, treatment with a C5aR antagonist significantly attenuated monocyte/macrophage infiltration, perhaps a result of reduced levels of monocyte chemoattractant protein 1 and the intercellular adhesion molecule 1. In vitro, C5aR antagonism inhibited intercellular adhesion molecule 1 upregulation in primary mouse aortic endothelial cells and reduced adhesion of peripheral blood mononuclear cells. Furthermore, C5aR blockade markedly reduced alloreactive T cell priming. These results demonstrate that C5aR plays an important role in mediating acute kidney allograft rejection, suggesting that pharmaceutical targeting of C5aR may have potential in transplantation medicine.

Objective: Erythropoietin (EPO) has cytoprotective effects apart from its hematopoietic effects. We studied the effects of different EPO molecules on podocyte signaling in vitro and on podocyte survival in an experimental model of diabetic kidney injury (db/db mouse)., Methods: We elucidated intracellular signaling by epoetin-beta, darbepoetin-alpha, and the continuous erythropoietin receptor activator (CERA) in immortalized murine podocyte cultures. Moreover, we treated db/db mice with placebo or with CERA in a chronic (14-week) randomized controlled study. We also studied non-diabetic db/m mice as controls., Results: We could clearly demonstrate phosphorylation of the JAK/PI3K pathway and Akt signaling in podocytes by epoetin-beta, darbepoetin-alpha and CERA. In the long-term animal study we found significantly reduced podocyte numbers in placebo-treated db/db mice compared to db/m control mice (7.4 +/- 0.2 vs. 10.2 +/- 0.9 per glomerular field; p < 0.05). Chronic CERA treatment ameliorated podocyte loss in kidneys of diabetic animals (8.5 +/- 0.5 per glomerular field; p < 0.05 vs. placebo-treated db/db mice)., Conclusion: EPO activates pro-survival intracellular pathways in podocytes in vitro, and ameliorates diabetes-induced podocyte loss in vivo. Chronic EPO administration may be a feasible way to protect podocyte from diabetic injury., (Copyright 2008 S. Karger AG, Basel.)

This study explored the tissue-protective properties of the continuous erythropoietin receptor activator (CERA) in an experimental model of (nonischemic) diabetic kidney injury (i.e., the db/db mouse). Mice were randomly treated with placebo (n = 25), low-dosage CERA (n = 25), and high-dosage CERA (n = 25). Also studied were 25 nondiabetic db/m mice. Hematocrit was comparable in placebo and low-dosage CERA-treated mice but increased significantly with high-dosage CERA (P < 0.01 versus both). Significantly reduced expression of TGF-beta, vascular endothelial growth factor, and collagen IV was found in glomeruli and the tubulointerstitial area with CERA treatment, and these beneficial molecular effects were clearly dosage dependent (both P < 0.05 versus placebo). Similarly, CERA treatment caused a dosage-dependent increase in p-Akt, nephrin, and perlecan tissue expression (all P < 0.05 versus placebo). However, the accelerated mesangial expansion that was observed in placebo-treated db/db mice (versus db/m controls) was significantly reduced only in low-dosage CERA-treated mice (P < 0.01). Moreover, albuminuria was significantly reduced in low- but not high-dosage CERA-treated mice compared with placebo treatment (P < 0.05). In an ancillary study, phlebotomy was performed in high-dosage CERA-treated db/db mice to keep hematocrit within normal (baseline) levels. This procedure resulted in significantly (P < 0.05) less albuminuria as compared with high-dosage CERA-treated mice without phlebotomy, thus preserving the tissue-protective potential of CERA. Long-term CERA treatment has beneficial dosage-dependent effects on molecular pathways of diabetic kidney damage. Low-dosage CERA does not affect hematocrit and therefore may be a feasible method of tissue protection in this setting.

Protein kinase C (PKC), a family of 12 distinct serine-threonine kinases, is an important intracellular signaling pathway involved in various cellular functions, such as proliferation, hypertrophy, apoptosis, and adhesion. PKC-epsilon, a novel PKC isoform that is activated in the diabetic kidney, has been demonstrated to have a central role in the underlying signaling infrastructure of myocardial ischemia and hypertrophy. The renal phenotype of PKC-epsilon(-/-) mice was studied with regard to renal hypertrophy and fibrosis. PKC-epsilon(-/-) deficient knockout mice were generated and then killed after 6, 16, and 26 wk of life. Kidney/body weight ratio did not show any significant group difference compared with appropriate wild-type controls. Urinary albumin/creatinine ratio remained normal in wild-type mice, whereas PKC-epsilon(-/-) mice after 6 and 16 wk showed elevated albuminuria. Masson-Goldner staining revealed that tubulointerstitial fibrosis and mesangial expansion were significantly increased in PKC-epsilon(-/-) mice. However, this profibrotic phenotype was not observed in other organs, such as liver and lung. Immunohistochemistry of the kidneys from PKC-epsilon(-/-) mice showed increased renal fibronectin and collagen IV expression that was further aggravated in the streptozotocin-induced diabetic stress model. Furthermore, TGF-beta(1), phospho-Smad2, and phospho-p38 mitogen-activate protein kinase expression was increased in PKC-epsilon(-/-) mice, suggesting a regulatory role of PKC-epsilon in TGF-beta(1) and its signaling pathway in the kidney. These results indicate that deletion of PKC-epsilon mediates renal fibrosis and that TGF-beta1 and its signaling pathway might be involved. Furthermore, these data suggest that activation of PKC-epsilon in the diabetic state may rather represent a protective response to injury than be a mediator of renal injury.

Albuminuria in diabetic nephropathy is due to endothelial dysfunction, a loss of negative charges in the basement membrane, and changes a of the slit-membrane diaphragm composition. We have recently shown that protein kinase C alpha (PKCalpha)-deficient mice are protected against the development of albuminuria under diabetic conditions. We here tested the hypothesis that PKCalpha mediates the hyperglycemia-induced downregulation of the slit-diaphragm protein nephrin. After 8 weeks of streptozotocin (STZ)-induced hyperglycemia the expression of glomerular nephrin was significantly reduced. In contrast, other slit-diaphragm proteins such as podocin and CD2AP were unaltered in diabetic state. In PKCalpha-/- mice, hyperglycemia-induced downregulation of nephrin was prevented. Podocin and CD2AP remained unchanged. In addition, the nephrin messenger RNA expression was also reduced in hyperglycemic wild-type mice but remained unaltered in PKCalpha-/- mice. We postulate that the underlying mechanism of the hyperglycemia-induced regulation of various proteins of the glomerular filtration barrier is a PKCalpha-dependent regulation of the Wilms' Tumor Suppressor (WT1) which previously has been shown to act as a direct transcription factor on the nephrin promoter. Our data suggest that PKCalpha activation may be an important intracellular signaling pathway in the regulation of nephrin expression and glomerular albumin permeability in the diabetic state.

The regulation of blood pressure is a complex process, involving several organs. The kidney plays a major role and is involved in the initiation and maintenance of hypertension. Mechanisms involved are: (1) the sympathetic nerveous system, (2) the renin-angiotensin system, (3) the regulation of sodium and water balance, (4) the production of vasoactive substances such as endothelin, adenosine or nitric oxide (NO), and (5) structural alterations such as a reduced number of glomeruli and nephrons. Several therapeutic intervention strategies affecting these mechanisms have already proven to be effective antihypertensive drugs.

Long-acting third-generation dihydropyridine calcium channel blockers (CCBs) improve endothelial dysfunction and prevent cardiovascular events in humans, but their cellular and molecular mechanisms of tissue protection are not elucidated in detail. We assessed organ (renal) protection by the highly lipophilic CCB lercanidipine in a double-transgenic rat (dTGR) model with overexpression of human renin and angiotensinogen genes. We randomly treated dTGR with lercanidipine (2.5 mg/kg/day; n=20) or vehicle (n=20) for 3 wk. Furthermore, we explored the influence of lercanidipine on protein kinase C (PKC) signaling in vivo and in vitro using endothelial and vascular smooth muscle cell cultures. Cumulative mortality was 60% in untreated dTGR, whereas none of the lercanidipine-treated animals died (P<0.001). We found significantly less albuminuria and improved renal function in lercanidipine-treated dTGR (both P<0.05). Lercanidipine treatment also significantly (P<0.05) reduced blood levels of the endogenous NOS inhibitor asymmetric dimethylarginine. On histological examination, we observed significantly less tissue inflammation and fibrosis in lercanidipine-treated animals (both P<0.05). Lercanidipine significantly inhibited angiotensin (ANG) I-mediated PKC-alpha and -delta activation in vivo and in vitro, partly due to reduced intracellular calcium flux. As a result, lercanidipine improved endothelial cell permeability in vitro. Lercanidipine prevents tissue injury and improves survival in a model of progressive organ damage. These effects may result, at least in part, from inhibition of tissue inflammation as well as improved NO bioavailability. Modulation of PKC activity may be an important underlying intracellular mechanism.

We report three patients with massive eosinophilia of different etiology who developed bronchoconstriction, hypotension, and shock shortly after dialysis or leukapheresis had been begun. In two cases, ethylene oxide-free materials had been used ruling out an allergic reaction related to this compound. Degranulation of eosinophils with release of eosinophil peroxidase may have caused the observed adverse reactions, as suggested by in vitro experiments with blood from the three patients. Our observations draw attention to the fact that extracorporeal therapies may initiate life-threatening complications in patients with severe eosinophilia.

Immune complex (IC) deposition induces an acute inflammatory response with tissue injury. IC-induced inflammation is mediated by inflammatory cell infiltration, a process highly regulated by the cell surface-specific receptor (uPAR), a binding partner for the urokinase-type plasminogen activator (uPA). We assessed the role of the uPA/uPAR system in IC-induced inflammation using the pulmonary reverse passive Arthus reaction in mice lacking uPA and uPAR compared with their corresponding wild-type controls. Both uPA-deficient C57BL/6J (uPA(-/-)) and uPAR-deficient mice on a mixed C57BL/6J (75%) x 129 (25%) background (uPAR(-/-)) demonstrated a marked reduction of the inflammatory response due to decreased production of proinflammatory mediators TNF-alpha and Glu-Leu-Arg (ELR)-CXC chemokine MIP-2. In uPAR(-/-) animals, the reduction of inflammatory response was more pronounced because of decreased migratory capacity of polymorphonuclear leukocytes. We show that the uPA/uPAR system is activated in lung of wild-type mice, particularly in resident alveolar macrophages (AM), early in IC-induced alveolitis. This activation is necessary for an adequate C5a anaphylatoxin receptor signaling on AM that, in turn, modulates the functional balance of the activating/inhibitory IgG FcgammaRs responsible for proinflammatory mediator release. These data provide the first evidence that the uPA/uPAR plays an important immunoregulatory role in the initiation of the reverse passive Arthus reaction in the lung by setting the threshold for C5a anaphylatoxin receptor/FcgammaR activation on AM. The findings indicate an important link between the uPA/uPAR system and the two main components involved in the IC inflammation, namely, complement and FcgammaRs.

Background: Circulating bone marrow-derived endothelial progenitor cells (EPCs) promote vascular repair, and their number correlates with endothelial function and cardiovascular risk in humans. In uremic patients, the number of functionally active EPCs is reduced. Thus, we assessed EPCs in stable patients 6 months or more after renal transplantation., Methods: We analyzed circulating CD34+ hematopoietic progenitor cells (HPCs) using flow cytometry and EPCs (in vitro assay) in 74 renal transplant patients (51.6+/-11.5 years; 46 males), 74 age-matched healthy subjects, and 29 patients with preterminal renal failure., Results: EPC numbers were similar in renal transplant recipients and controls (232+/-92 vs. 250+/-103/high power field; n.s.), but were significantly higher than in uremic patients (160+/-97/high power field; P=0.004). In addition, transplant recipients had more HPCs than controls (2.71+/-1.65 vs. 1.99+/-1.12 /microl; P=0.004) and uremic patients (1.64+/-0.96/microl; P=0.001). EPCs in renal transplant recipients correlated significantly with graft function(that is, Cockcroft-Gault clearance [r=0.294; P=0.012]), but not with age or HPCs. Moreover, in the multiple regression analysis, graft function (r=0.332; P=0.01) and diastolic blood pressure (r=-0.278; P=0.03) were independent predictors of EPCs. In vitro, sera from renal transplant recipients with poor graft function significantly inhibited EPC differentiation compared with sera from patients with a clearance above 50 mL/min (151+/-54 vs. 274+/-94 EPCs/high power field; P=0.02)., Conclusions: EPC numbers in stable renal transplant recipients are comparable to those found in healthy subjects. In addition, graft function is a significant determinant of EPCs. Prospective studies should explore whether improvement of EPCs influences cardiovascular risk in renal transplant recipients.

Background: The hematopoietic cytokine erythropoietin has cytoprotective effects in endothelial cells in vitro that are mediated through direct activation of the pro-survival Akt tyrosine kinase signaling pathway. We tested the hypothesis that low-dose therapy with the long-acting recombinant human erythropoietin analogue darbepoetin alpha protects vascular endothelium in vivo in a classic remnant kidney rat model characterized by severe endothelial damage, progressive vascular sclerosis, and ischemia-induced tissue fibrosis., Methods and Results: Using a parallel group study design, we randomly assigned animals after 5/6 nephrectomy to treatment with either saline (n=36) or 0.1 microg/kg body wt darbepoetin (n=24) subcutaneously once weekly. We monitored hematocrit, blood pressure, and serum creatinine regularly and obtained renal tissue 6 weeks after nephrectomy for morphological and immunohistochemical analysis. Darbepoetin-treated animals had significantly improved survival compared with saline-treated controls (63% versus 33%; P<0.05), although hematocrit levels were similar in both groups. Darbepoetin treatment ameliorated endothelial damage; attenuated the composite tissue injury score (saline 1.9+/-0.4; darbepoetin 0.4+/-0.2; P<0.001), which included vascular sclerosis, glomerulosclerosis, and tubulointerstitial damage; and preserved renal function. We found persistent activation of the pro-survival Akt signaling pathway in endothelial and epithelial glomerular cells in darbepoetin-treated animals, accompanied by a significant reduction of apoptotic cell death in renal tissue., Conclusions: Low-dose darbepoetin treatment confers vascular and tissue protection that is associated with persistent stimulation of the pro-survival Akt signaling pathway. The use of recombinant human erythropoietin or analogues may have utility in preventing ischemia-related progressive vascular injury and organ failure.

Activation of protein kinase C (PKC) isoforms has been implicated in the pathogenesis of diabetic nephropathy. We showed earlier that PKC-alpha is activated in the kidneys of hyperglycemic animals. We now used PKC-alpha(-/-) mice to test the hypothesis that this PKC isoform mediates streptozotocin-induced diabetic nephropathy. We observed that renal and glomerular hypertrophy was similar in diabetic wild-type and PKC-alpha(-/-) mice. However, the development of albuminuria was almost absent in the diabetic PKC-alpha(-/-) mice. The hyperglycemia-induced downregulation of the negatively charged basement membrane heparan sulfate proteoglycan perlecan was completely prevented in the PKC-alpha(-/-) mice, compared with controls. We then asked whether transforming growth factor-beta1 (TGF-beta1) and/or vascular endothelial growth factor (VEGF) is implicated in the PKC-alpha-mediated changes in the basement membrane. The hyperglycemia-induced expression of VEGF165 and its receptor VEGF receptor II (flk-1) was ameliorated in PKC-alpha(-/-) mice, whereas expression of TGF-beta1 was not affected by the lack of PKC-alpha. Our findings indicate that two important features of diabetic nephropathy-glomerular hypertrophy and albuminuria-are differentially regulated. The glucose-induced albuminuria seems to be mediated by PKC-alpha via downregulation of proteoglycans in the basement membrane and regulation of VEGF expression. Therefore, PKC-alpha is a possible therapeutic target for the prevention of diabetic albuminuria.

Background: Circulating bone marrow-derived endothelial progenitor cells (EPCs) promote vascular repair. Their number in peripheral blood correlates with endothelial function and cardiovascular risk in humans. We explored whether uremia influences the number of EPCs., Methods: We assessed circulating CD34+ hematopoietic progenitor cells in whole blood using flow cytometry and EPCs (in vitro assay) in 46 patients with advanced renal failure and in 46 age- and gender-matched healthy subjects. Further, the effect of uremia on EPC differentiation was studied in vitro and in vivo., Results: Both in renal patients (r= 0.34, P < 0.02) and in healthy subjects (r= 0.32, P= 0.04) the number of EPCs was significantly correlated to the absolute number of CD34+ hematopoietic progenitor cells. Renal patients had significantly fewer EPCs than healthy subjects, however (167 +/- 15 cells/high power field vs. 235 +/- 17 cells/high power field; P < 0.05). Uremic serum significantly (P < 0.05) inhibited EPC differentiation and functional activity in vitro. Amelioration of uremia after institution of renal replacement therapy in patients with terminal renal failure also significantly (P < 0.05) increased the number of EPCs., Conclusion: Uremia inhibits differentiation of EPCs. This may impair cardiovascular repair mechanisms in patients with renal failure.

Circulating bone marrow-derived endothelial progenitor cells (EPCs) promote vascular reparative processes and neoangiogenesis, and their number in peripheral blood correlates with endothelial function and cardiovascular risk. We tested the hypothesis that the cytokine erythropoietin (EPO) stimulates EPCs in humans. We studied 11 patients with renal anemia and 4 healthy subjects who received standard doses of recombinant human EPO (rhEPO). Treatment with rhEPO caused a significant mobilization of CD34(+)/CD45(+) circulating progenitor cells in peripheral blood (measured by flow cytometry), and increased the number of functionally active EPCs (measured by in vitro assay) in patients (week 2, 312% +/- 31%; week 8, 308% +/- 40%; both P <.01 versus baseline) as well as in healthy subjects (week 8, 194% +/- 15%; P <.05 versus baseline). The effect on EPCs was already observed with an rhEPO dose of about 30 IU/kg per week. Administration of rhEPO increased the number of functionally active EPCs by differentiation in vitro in a dose-dependent manner, assessed in cell culture and by tube formation assay. Furthermore, rhEPO activates the Akt protein kinase pathway in EPCs. Erythropoietin increases the number of functionally active EPCs in humans. Administration of rhEPO or EPO analogs may open new therapeutic strategies in regenerative cardiovascular medicine.

Sclerosis and increased matrix expression in diabetes are mediated by glucose-induced transforming growth factor (TGF)-beta1 expression. The intracellular effects of high glucose occur at least in part by way of protein kinase C (PKC). We previously described a role for PKC-alpha in glucose-induced permeability. We now investigated the hypothesis that glucose-induced expression of TGF-beta1 and its receptors (TGF-beta-R1 and -R2) are mediated by activation of this PKC isoform. TGF-beta1 and TGF-beta-R expressions were determined in vascular smooth muscle cells (VSMCs) by immunocytochemistry and Western blotting. PKC isoforms were assessed by confocal microscopy. PKC isoforms were inhibited with antisense oligodeoxynucleotides. PKC-alpha was upregulated by overexpression or microinjection. High glucose (20 mmol/L) increased VSMC TGF-beta1 and TGF-beta-R1 expression but not TGF-beta-R2 expression. PKC inhibitors and specific PKC-alpha downregulation by antisense treatment prevented this effect, whereas antisense treatment against PKC-beta, -epsilon, and -zeta had no influence. PKC-alpha overexpression increased TGF-beta1 and TGF-beta-R1 expression but not TGF-beta-R2 expression. PKC-alpha microinjection into individual VSMCs also increased TGF-beta1 and TGF-beta-R immunofluorescence. Last, VSMCs from PKC-alpha-deficient mice did not respond to high glucose compared with VSMCs from wild-type mice. We propose that high glucose-induced TGF-beta1 and TGF-beta-R1 expression is mediated by PKC-alpha. Our findings suggest an autocrine feedback mechanism and a possible role for PKC-alpha in diabetic vascular disease.

Postischemic acute renal failure (ARF) is common and often fatal. Cellular mechanisms include cell adhesion, cell infiltration and generation of oxygen free radicals, and inflammatory cytokine production. Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors ("statins") directly influence inflammatory mechanisms. The hypothesis that ischemia-induced ARF could be ameliorated with statin treatment was investigated and possible molecular mechanisms were analyzed in a uninephrectomized rat model. Male Sprague-Dawley rats were pretreated with cerivastatin (0.5 mg/kg) or vehicle for 3 d. Ischemic ARF was induced by left renal artery clipping for 45 min, while the right kidney was being removed. After 24 h of ARF, serum creatinine levels were increased 7.5-fold in vehicle-treated control animals with ARF, compared with sham-operated animals (P < 0.005). Statin treatment reduced the creatinine level elevation by 40% (P < 0.005). Simultaneously, ischemia-induced severe decreases in GFR were significantly ameliorated by statin treatment (sham operation, 0.95 +/- 0.09 ml/min, n = 13; ischemia without treatment, 0.06 +/- 0.02 ml/min, n = 9; ischemia with statin pretreatment, 0.21 +/- 0.03 ml/min, n = 11; P < 0.001). Furthermore, statin pretreatment prevented the occurrence of tubular necrosis, with marked loss of the brush border, tubular epithelial cell detachment, and tubular obstruction in the S3 segment of the outer medullary stripe. In addition, monocyte and macrophage infiltration was almost completely prevented, intercellular adhesion molecule-1 upregulation was greatly decreased, and inducible nitric oxide synthase expression was reduced. Fibronectin and collagen IV expression was reduced, approaching levels observed in sham-operated animals. In vehicle-treated rats with ARF, mitogen-activated protein kinase extracellular activated kinase-1/2 activity was increased and the transcription factors nuclear factor-kappaB and activator protein-1 were activated. Statin treatment reduced this activation toward levels observed in sham-operated rats. The data suggest that hydroxy-3-methylglutaryl coenzyme A reductase inhibition protects renal tissue from the effects of ischemia-reperfusion injury and thus reduces the severity of ARF. The chain of events may involve anti-inflammatory effects, with inhibition of mitogen-activated protein kinase activation and the redox-sensitive transcription factors nuclear factor-kappaB and activator protein-1.

Caveolae are plasma membrane invaginations that may play an important role in numerous cellular processes including transport, signaling, and tumor suppression. By targeted disruption of caveolin-1, the main protein component of caveolae, we generated mice that lacked caveolae. The absence of this organelle impaired nitric oxide and calcium signaling in the cardiovascular system, causing aberrations in endothelium-dependent relaxation, contractility, and maintenance of myogenic tone. In addition, the lungs of knockout animals displayed thickening of alveolar septa caused by uncontrolled endothelial cell proliferation and fibrosis, resulting in severe physical limitations in caveolin-1-disrupted mice. Thus, caveolin-1 and caveolae play a fundamental role in organizing multiple signaling pathways in the cell.

Unlabelled: The ACE D- and the ecNOS a-allele have been associated with an adverse prognosis in patients with glomerulonephritis (GN). Using genomic DNA we investigated by RT-PCR whether the two polymorphisms are useful prognostic markers in GN patients. In patients with primary GN (IgA-GN n = 70, membranous GN n = 23, FSGS n = 17, MPGN n = 6) neither the whole group nor disease-specific subgroups exhibited any alterations from the normal ACE genotype distribution. No significant associations were detected between the ACE genotype and the development of hypertension, antihypertensive therapy required, progression rate of the disease, age of diagnosis and the antiproteinuric response to ACE-inhibition. In 40 IgA-GN patients with ESRD no increased prevalence of the D-allele was noted. The distribution of the ecNOS-alleles in the above patients (a-allele 22%, b-allele 78%) was comparable to that of the normal controls. No association with any of the parameters mentioned above were detected in the case of the ecNOS-alleles., Conclusions: In our Caucasian patients neither the determination of the ACE nor the ecNOS genotype offered any diagnostic or prognostic help.