PO-15 - Antiangiogenic small molecule ligands of FGF2 derived from the endogenous inhibitor thrombospondin-1.

INTRODUCTION: Platelet thrombospondin-1 (TSP-1) is a major endogenous regulator of growth factor activity in physiological and pathological processes, including tumor onset, progression and angiogenesis. We previously demonstrated that TSP-1 binds to FGF-2, sequestering the growth factor and inhibiting its angiogenic activity. We also identified a non-peptidic antiangiogenic compound (SM27) that retains the structural and functional properties of the FGF2-binding sequence of TSP-1. AIM: To identify new small molecule inhibitors of FGF2 that recapitulate the structure and functional properties of the FGF-2-binding site of TSP-1, by investigating the chemical space around SM27. MATERIALS AND METHODS: A similarity-based screening of small molecule libraries has been used to identify candidates, followed by docking calculations, and evaluation of the activity of the resulting compounds in biochemical and biophysical assays, to assess interaction with FGF2, and in experimental models of angiogenesis, to assess biological activity. RESULTS: The used integrated approach allowed selecting 7 bi-naphthalenic compounds that bound FGF2 inhibiting FGF2 binding to both heparan sulfate proteoglycans and FGFR1. The compounds inhibited FGF2-induced endothelial cell proliferation, vessel sprouting from aortic rings and angiogenesis in the chorioallantoic membrane assay, with improved potency over SM27. CONCLUSIONS: We have identified new compounds that are valuable as FGF inhibitors for potential therapeutic purposes. Moreover, these compounds are useful chemical tools to identify the minimal stereochemical requirements for FGF2 binding and activity to improve the design of new agents for antineoplastic therapy. ACKNOWLEDGEMENT: Supported by AIRC (Associazione Italiana per la Ricerca sul Cancro).

Cellfood™ improves respiratory metabolism of endothelial cells and inhibits hypoxia-induced reactive oxygen species (ros) generation.

Endothelial mitochondria, the major site of ATP generation, modulate the intracellular dynamics of reactive oxygen species (ROS), which, in turn, control endothelial function. Adequate oxygen (O(2)) supply is required by endothelial cells (EC). Both hypoxia and hyperoxia may favor the overproduction of ROS leading to oxidative stress, mitochondrial damage and endothelial dysfunction. We investigated the capability and mechanisms of Cellfood™ (CF), an antioxidant compound, to modulate O(2) availability and mitochondrial respiratory metabolism and to regulate ROS generated by hypoxia in EC in vitro. Human umbilical vein endothelial cells (HUVEC) and ECV-304 were evaluated for the O(2) consumption using a Clark's electrode. The O(2) consumption rate rose, during the first minutes after CF addition and was associated with increase in mitochondrial oxidative capacity and good cell viability. Similar behaviours were observed when EC were exposed to CF for up to 8 days. The O(2) consumption increased and was accompanied by both intracellular rise of ATP and maintainment of LDH concentration. Hypoxia-induced ROS generation was significantly inhibited by CF, through the up-regulated expression of MnSOD, an anti-oxidant responsible for mitochondrial function preservation. The EC hypoxic response is mediated by the hypoxia master regulator HIF-1alpha whose activation was attenuated by CF, in concomitance with MnSOD up-regulation. Our results suggest a role for CF in improoving respiratory metabolism and in activating anti-oxidant mechanisms in EC, thus preserving endothelial function.

In situ split liver transplantation for adult and pediatric recipients: an answer to organ shortage.

BACKGROUND: We report our initial experience with in situ split liver transplantation (SLT) for adult and pediatric patients. PATIENTS AND METHODS: From June 2003 to August 2005, 177 liver transplantations in 165 patients, 133 adults (81%) and 32 children (19%), were performed at our institution. Over this period, 45 liver transplantations (25%) were performed with an in situ split liver technique in 44 patients: 17 (39%) were adults and 27 (61%) children. All of the adult split liver recipients were transplanted with an extended right graft (ERG; segments I + IV-VIII), while pediatric recipients received in 23 cases a left lateral segment (LLS; segments II-III) and in 4 cases an ERG from a pediatric donor. The 45 split liver grafts (21 ERGs and 24 LLSs) were generated from 35 donors. In 10 cases we used both grafts generated with an in situ split procedure to transplant our patients, while in 25 cases the procurement procedure was performed in collaboration with other transplant centers. RESULTS: After a median follow-up of 9 months (range, 1-27 months), the overall patient survival rate was 88% for adult patients and 82% for pediatric patients. Graft survivals were 88% and 79%, respectively. Two adult patients (12%) died from sepsis in the early postoperative period. Five children (18%) died after their transplantations. Only one pediatric recipient (2%) of primary SLT underwent retransplantation. Vascular complications were absent in adult recipients, whereas 4 arterial (14%) and 4 venous (14%) complications developed in the pediatric population. The incidence of biliary complications was 23% in adult and 18% in pediatric recipients. CONCLUSIONS: The use of in situ SLT for adult and pediatric populations allowed us to expand the cadaveric donor pool, significantly eliminating pediatric waiting list mortality without penalizing the adult population.

Corticosteroid-free immunosuppression in pediatric liver transplantation: safety and efficacy after a short-term follow-up.

BACKGROUND: We report our results with the use of corticosteroid-free immunosuppression after pediatric liver transplantation, evaluating the efficiency and safety of this protocol in the early posttransplantation period. PATIENTS AND METHODS: From July 2003 to October 2005, 34 liver transplantations were performed in 32 pediatric patients (19 boys, 13 girls) at our institution. Recipient median age was 5 years (range, 0.2-14 years), and median body weight was 10 kg (range, 4-49 kg). Twenty-seven patients received a graft from in situ split liver transplantation, 5 a whole graft. Twenty-nine children (90%) received an immunosuppressive therapy based on methylprednisolone IV bolus at reperfusion (10 mg/kg) plus tacrolimus given at an initial dose of 0.08 mg/kg/d and then adjusted to obtain whole blood trough levels of 10 to 15 ng/mL during the first 3 months and 5 to 10 ng/mL after the 3rd month; basiliximab was given on postoperative days 0 and 4. Biopsy-proven acute rejection episodes were treated by methylprednisone IV boluses. RESULTS: After a median follow-up of 9 months (range, 1-27 months), the overall patient survival rate was 84% and graft survival rate was 79%. Three children (9%) died after their transplantations. Three (9%) experienced episodes of biopsy-proven acute rejection, always treated with IV steroid boluses. Mean RAI score was 4. One patient experienced PTLD that resolved with temporary reduction of immunosuppression. Cytomegalovirus infection rate was 14%. Sepsis occurred in 2 cases (6%). CONCLUSIONS: Initial results with a steroid-free immunosuppressive protocol are encouraging, with low rates of acute rejection and infectious complications as in steroid-based protocols.

Productive infection of HUVEC by HHV-8 is associated with changes compatible with angiogenic transformations.

Kaposi's Sarcoma (KS) is an angioproliferative disease associated with human herpesvirus 8 (HHV-8) infection. We have characterized the morphologic and phenotypic modifications of HUVEC in a model of productive HHV-8 infection. HHV-8 replication was associated with ultra-structural changes, flattened soma and a loss of marginal folds and intercellular contacts, and morphologic features, spindle cell conversion and cordon-like structures formation. Phenotypic changes observed on cordon-like structures included partial loss and redistribution of CD31/PECAM-1 and VE-cadherin, uPAR up-regulation and de novo expression of CD13/APN. Such changes demonstrate the induction, in HUVEC, of an angiogenic profile. Most of these findings are directly linked to HHV-8-encoded proteins expression, suggesting that HHV-8 itself may participate to the initial steps of the angiogenic transformation in KS.

Pediatric liver transplantation: preliminary results at Istituto Mediterraneo Trapianti e Terapie ad Alta Specializzazione.

Between July 2003 and November 2004 14 pediatric liver transplantations (LTx) have been performed in 12 children using cadaveric donors. The primary diseases were as follows biliary atresia in 9 cases, whereas the other 3 children were affected by cystic fibrosis, Langherans cells histiocytosis, and hepatoblastoma, respectively. Median patient waiting time was 103 days (range, 2-158); no patient died while on the waiting list. Patients who underwent transplantation included 7 boys and 5 girls, ranging in age from 6 months to 14 years (median age, 5 years). Recipient median weight was 16 kg (range, 6-38). Donor median age was 19 years (range, 3-47), whereas donor median weight was 74 kg (range, 15-90). All children who underwent primary LTx were United Network for Organ Sharing (UNOS) status 2B. Of the 12 transplanted patients, 9 received a left lateral segment (LLS) from an in situ split liver, whereas 3 received a whole graft. Two children developed an episode of acute cellular rejection on the seventh postoperative day, which was treated successfully with a course of intravenous steroids for 3 days. After a median follow-up of 245 days, 10 children are alive but 2 children died due to primary nonfunction (PNF) on the second postoperative day and septic shock on the fifth postoperative day after retransplantation for acute hepatic artery thrombosis, respectively. One child who underwent retransplantation for hepatic artery thrombosis on the 31st postoperative day after primary LTx is currently alive. Evaluation of our initial data suggests that the split liver technique has the potential to meet the needs of pediatric LTx allowing grafting early in the course of the original disease and reducing waiting time.

Changes in serum electrolytes during treatment of patients in liver failure with molecular adsorbent recirculating system.

PURPOSE: To study the effect of MARS on serum electrolytes during liver failure. DESIGN: Twenty-three patients admitted to a quaternary health care facility from September 2000 to May 2002, 22 adults and 1 child, 11 males (48%) and 12 females (52%), age 15-70 (median 53), treated with MARS for: 12 acute-on-chronic liver failure (52%); 4 fulminant hepatic failure (17%); 3 intractable pruritus (13%); 2 primary-non-function (9%); 2 following major liver resection (9%). PROCEDURES: Sodium, potassium, chloride, phosphorus, calcium, and magnesium were measured in the serum, ultrafiltrate and albumin circuit before and after MARS. STATISTICAL METHODS: A comparison of electrolyte concentrations, before and after MARS, was performed using a paired t test. MAIN FINDINGS: Serum electrolyte concentrations before and after MARS, while statistically significant in some cases, were very small, and of no clinical relevance. CONCLUSION: MARS exchanges potassium, chloride, calcium, and magnesium by ultrafiltration; sodium by the albumin dialysis.

Lactate levels in open interstitial thermal ablation for liver tumors.

Intraoperative radio frequency interstitial thermal ablation (RITA) may result in a reduction of the functional hepatic reserve. To assess this further, we evaluated perioperative lactate levels as a measure of hepatic dysfunction. Sixteen patients scheduled for open RITA (O-RITA) were enrolled in the study. Arterial lactate levels (mmol/L) were measured prior to tumor needle insertion (T0), after O-RITA completion (T1), after wound closure (T2) and 24 hrs after surgery (T3). Correlation between hemodynamic parameters including MAP, and CVP, at T0, T1, T2, T3 and the perioperative rate of lactate production were also analyzed. Total bilirubin, transaminases and international normalized ratio for prothrombin activity (INR) were measured preoperatively and postoperative at day 1, 2, 3 and 7. Data are expressed as mean +/- SD and analyzed with ANOVA. Additionally, the Duncan post hoc test was used for multiple comparisons of the differences in mean values. A p-value <0.05 was considered significant. Lactate levels did not increase significantly at time points specified above (P = NS). Similarly, hemodynamic parameters analyzed did not show any significant change at the different time points (P = NS). Total bilirubin and INR did not demonstrate statistically significant changes at the aforementioned time points. Serum transaminases peaked during the immediate postoperative period and normalized to preoperative values by one-week post surgery. These results demonstrate that O-RITA does not induce hyperlactatemia and does not reduce the functional residual liver parenchyma.

The hepatic artery in liver transplantation and surgery: vascular anomalies in 701 cases.

The purpose of this study is to report the variations in hepatic arterial supply of a mixed population of organ donors in which the anatomy was individually examined during the bench surgery, and patients who underwent a selective angiogram of the celiac axis and superior mesenteric artery. We reviewed the donor forms and/or angiograms of 701 patients. The donor forms were completed personally by one of the authors, while all the radiology images were obtained through studies performed by one single radiologist. The arterial anatomy was anomalous in 296 out of 701 cases with an overall incidence of hepatic artery anomalies of 42.22%. In this paper we describe previously unreported arterial anomalies of the hepatic artery, collecting the second largest series of hepatic artery anatomical variations of the English literature. This anatomical update can be useful for transplant and general surgeons, as well as vascular radiologists.

Malignant fibrous histiocytoma of the gallbladder: case report and review of the literature.

Malignant fibrous histiocytoma is a soft tissue sarcoma of mesenchymal origin. It can rarely present as a primary gallbladder tumor with only five cases having been reported to date in the English literature. Here we report the sixth documented case of malignant fibrous histiocytoma of the gallbladder, and we review all other cases reported. The outcome of the visceral sarcomas is poor when compared with tumors arising from the soft tissues. The treatment of primary malignant fibrous histiocytomas of the gallbladder is surgery. However, tumor recurrence is the norm even if wide clean margins are obtained. In contrast to tumors arising from the extremities the role of adjuvant radiotherapy and chemotherapy is less clear in the case of retroperitoneal and visceral sarcomas. Our patient is still alive and free of disease 46 weeks after surgery. The fact that this is the longest survival reported to date underscores the dismal prognosis of this disease.

Fluorescent dyes for cell viability: an application on prefixed conditions.

In recent years increasing attention has been given to apoptosis for its role in pathologic, organogenetic and homeostatic phenomena. Acridine orange (AO), Hoechst 33342 (HO) and propidium iodide (PI) are among the most used fluorescent dyes used to analyse cell culture viability. In fact, they respectively show specificity for living, apoptotic and late apoptosis/necrosis states. We explored whether HO, AO and PI can be used on prefixed monolayers of three commonly used cell lines. Here we mainly describe the metachromatic effects obtained by fluorescence microscopy with double and triple dye combinations. Furthermore, we propose an easy staining method in which a balanced sequential treatment with HO, AO and PI allows identification of different viability states onto fixed cells by using a long-pass FITC filter. This method extends the spectrum of suitable applications for these dyes in fluorescence viability detection onto previously fixed (prefixed) samples.

A new Chinese hamster ovary cell line expressing alpha2,6-sialyltransferase used as universal host for the production of human-like sialylated recombinant glycoproteins.

Chinese hamster ovary (CHO) cells are widely employed to produce glycosylated recombinant proteins. Our group as well as others have demonstrated that the sialylation defect of CHO cells can be corrected by transfecting the alpha2,6-sialyltransferase (alpha2,6-ST) cDNA. Glycoproteins produced by such CHO cells display both alpha2,6- and alpha2,3-linked terminal sialic acid residues, similar to human glycoproteins. Here, we have established a CHO cell line stably expressing alpha2,6-ST, providing a universal host for further transfections of human genes. Several relevant parameters of the universal host cell line were studied, demonstrating that the alpha2,6-ST transgene was stably integrated into the CHO cell genome, that transgene expression was stable in the absence of selective pressure, that the recombinant sialyltransferase was correctly localized in the Golgi and, finally, that the bioreactor growth parameters of the universal host were comparable to those of the parental cell line. A second step consisted in the stable transfection into the universal host of cDNAs for human glycoproteins of therapeutic interest, i.e. interferon-gamma and the tissue inhibitor of metalloproteinases-1. Interferon-gamma purified from the universal host carried 40.4% alpha2,6- and 59.6% alpha2,3-sialic acid residues and showed improved pharmacokinetics in clearance studies when compared to interferon-gamma produced by normal CHO cells.

Glomerular filtration is required for transfection of proximal tubular cells in the rat kidney following injection of DNA complexes into the renal artery.

Gene transfer to the kidney can be achieved with various DNA vectors, resulting in transgene expression in glomerular or tubular districts. Controlling transgene destination is desirable for targeting defined renal cells for specific therapeutic purposes. We previously showed that injection of polyplexes into the rat renal artery resulted in transfection of proximal tubular cells. To investigate whether this process involves glomerular filtration of the DNA-containing particles, fluorescent polyethylenimine polyplexes were prepared, containing fluoresceinated poly-L-lysine. This allowed visualization of the route of the particles into the kidney. Our polyplexes were filtered through the glomerulus, since fluorescent proximal tubuli were observed. Conversely, fluorescent lipopolyplexes containing the cationic lipid DOTAP were never observed in tubular cells. Size measurements by laser light scattering showed that the mean diameter of polyplexes (93 nm) was smaller than that of lipopolyplexes (160 nm). The size of the transfecting particles is therefore a key parameter in this process, as expected by the constraints imposed by the glomerular filtration barrier. This information is relevant, in view of modulating the physico-chemical properties of DNA complexes for optimal transgene expression in tubular cells. Gene Therapy (2000) 7, 279-285.

Development and characterization of pituitary GH3 cell clones stably transfected with a human proinsulin cDNA.

Successful beta-cell replacement therapy in insulin-dependent (type I) diabetes is hindered by the scarcity of human donor tissue and by the recurrence of autoimmune destruction of transplanted beta cells. Availability of non-beta cells, capable of releasing insulin and escaping autoimmune recognition, would therefore be important for diabetes cell therapy. We developed rat pituitary GH3 cells stably transfected with a furin-cleavable human proinsulin cDNA linked to the rat PRL promoter. Two clones (InsGH3/clone 1 and 7) were characterized in vitro with regard to basal and stimulated insulin release and proinsulin transgene expression. Mature insulin secretion was obtained in both clones, accounting for about 40% of total released (pro)insulin-like products. Immunocytochemistry of InsGH3 cells showed a cytoplasmic granular insulin staining that colocalized with secretogranin II (SGII) immunoreactivity. InsGH3 cells/clone 7 contained and released in vitro significantly more insulin than clone 1. Secretagogue-stimulated insulin secretion was observed in both InsGH3 clones either under static or dynamic conditions, indicating that insulin was targeted also to the regulated secretory pathway. Proinsulin mRNA levels were elevated in InsGH3 cells, being significantly higher than in betaTC3 cells. Moreover, proinsulin gene expression increased in response to various stimuli, thereby showing the regulation of the transfected gene at the transcriptional level. In conclusion, these data point to InsGH3 cells as a potential beta-cell surrogate even though additional engineering is required to instruct them to release insulin in response to physiologic stimulations.

Renal and systemic nitric oxide synthesis in rats with renal mass reduction.

In rats undergoing renal mass reduction (RMR) oral supplementation with the nitric oxide (NO) precursor L-arginine increases glomerular filtration rate and ameliorates signs of glomerular injury, suggesting that chronic renal failure in the rats is a condition of low NO formation in the kidney. On the contrary, data are available that in the systemic circulation of uremics, both rats and human beings, NO is formed in excessive amounts and may contribute to platelet dysfunction and bleeding tendency, well-known complications of uremia. The present study was designed to clarify the pathophysiology of renal and systemic NO synthesis in uremia. We showed that renal ex vivo NO generation, measured as the conversion of [3H] L-arginine to [3H] L-citrulline, was lower than normal in RMR rats, seven days after surgery, and progressively worsened with time in close correlation with signs of renal injury. Consistent with these results, urinary excretion of the stable NO metabolites, NO2-/NO3-, significantly decreased in rats with RMR. To go deeper into the cellular origin and biochemical nature of this abnormality we used two histochemical approaches that could locate either NO synthase (NOS) catalytic activity (NADPH-diaphorase) or NOS isoenzyme expression (immunoperoxidase). NADPH-diaphorase documented a progressive loss of renal NOS activity in RMR rats that co-localized with a strong progressive decrease of inducible NOS isoenzyme (iNOS) immunostaining. At variance with iNOS, endothelial cell NOS (ecNOS) staining was rather comparable in RMR and control kidneys. At variance to the kidney, in the systemic circulation of RMR rats the synthesis of NO increased as reflected by higher than normal plasma NO2-/NO3- concentrations. High systemic NO likely derives from vessels as documented by the increased NOS activity and higher expression of both iNOS and ecNOS in the aorta of RMR rats. Up-regulation of systemic NO synthesis might be an early defense mechanism against hypertension of uremia. On the other hand, more NO available to circulating cells may sustain the bleeding tendency, a well-known complication of uremia.

[Short bowel syndrome: etiologic, pathogenetic aspects and principles of treatment]. / La sindrome da intestino corto: considerazioni etio-patogenetiche e principi di trattamento.

A significant problem in surgery following massive intestinal resection is the short bowel syndrome characterized by severe fluid and electrolyte loss, watery diarrhoea and malnutrition. Total parenteral nutrition and enteral nutrition are essential in the clinical course of the syndrome; their use for prolonged periods results in the gradual intestinal adaptation and greater absorptive and reservoir capacities of the intestinal remnant. Adjunctive surgery can slow rapid intestinal transit and induce growth of neo-small-bowel mucosa but is not recommended for routine use. The early results of intestinal transplantation in the treatment of short bowel syndrome are encouraging. Furthermore chronic rejection and systemic sepsis with failure of the graft must be considered and indicate that at present this procedure cannot be offered to every patient but will be a potential form of therapy in future.

Passive Heymann nephritis: evidence that angiotensin-converting enzyme inhibition reduces proteinuria and retards renal structural injury.

In nonimmunological models of renal damage, abnormal traffic of proteins through the glomerular capillary is one of the possible causes of renal disease progression. Here we investigated whether in a model of immune-mediated glomerulonephritis long-lasting proteinuria resulted in renal structural damage and whether chronic treatment with perindopril, an angiotensin-converting enzyme (ACE) inhibitor, lowered proteinuria and retarded disease progression. Passive Heymann nephritis (PHN), a model of human membranous nephropathy, was induced with 0.5 ml/100 g of rabbit anti-Fx1 A antibody in 26 male Sprague-Dawley rats. Animals were then divided into two groups of 13 rats each, given daily vehicle or perindopril (1 mg/kg p.o). Treatment started at day 7 when proteinuria was already present and lasted 12 months. An additional group of normal rats was used as control. Renal biopsies were taken at months 8 and 12. Untreated PHN rats showed a significant increase in systolic blood pressure starting from month 8, that was normalized by perindopril administration. Urinary protein excretion progressively increased with time in untreated PHN rats that developed focal and segmental glomerulosclerosis and tubulointerstitial damage. Perindopril significantly reduced proteinuria and limited glomerular and tubulointerstitial injury. Urinary excretion of endothelin-1 (ET-1) and transforming growth factor-beta 1 (TGF-beta 1), two major mediators of renal damage in other models of glomerulonephritis, increased with time in PHN but only the former correlated with the degree of glomerulosclerosis. The effect of perindopril on proteinuria and renal structural damage was associated with a significant reduction in urinary ET-1 but not TGF-beta 1, suggesting that ET-1 may be an important determinant of disease progression in experimental membranous nephropathy.

[Familial adenomatous polyposis. Problems encountered with rectum preservation in surgical treatment and life expectancy]. / La poliposi adenomatosa familiare. Problemi offerti dalla conservazione del retto nel trattamento chirurgico ed aspettative di vita.

Familial adenomatous polyposis is a genetically inherited disease with very high risk of colorectal cancer and with a large expression of multiple extracolonic malignancies. In recent years two surgical options are available for the treatment of FAP: total colectomy with ileorectal anastomosis and restorative proctocolectomy with ileoanal reservoir. The preservation of the rectum offers good quality of life and good functional results, but needs an accurate surveillance of the rectal stump and screening for the development of cancer. Restorative proctocolectomy is reserved for patients with large or confluent polyps of the rectum, for older patients and for those who had already had an ileorectal anastomosis and who develops subsequently large adenomas at increased risk for rectal cancer. Prophylactic procedures of surveillance, screening and surgery have reduced in patients at risk the incidence of colorectal cancer. But recently an increased number of malignant extracolonic tumors (gastric cancer, duodenal and periampullary cancer, small intestinal cancer, adrenal and thyroid cancer) and abdominal desmoid tumors, that causes a significant mortality, has been documented. The knowledge of the extracolonic features of FAP suggests a careful follow-up of the patients and the prevention and treatment of upper gastrointestinal cancers and desmoid disease.

ACE inhibition prevents renal failure and death in uninephrectomized MWF/Ztm rats.

Many studies have consistently documented that angiotensin converting enzyme (ACE) inhibitors prevent proteinuria and glomerulosclerosis in progressive renal disease, but very few data are available on whether they also prevent renal failure and death. The mechanisms of the beneficial effect of ACE inhibition are only partially understood. Recent data suggest that angiotensin II modulates renal synthesis of endothelin-1, a vasoactive peptide implicated in the process of renal injury. Here we investigated in a long-term study whether ACE inhibition ameliorated renal function in uninephrectomized (UNx) male MWF/Ztm rats. Three groups of rats at nine weeks of age underwent UNx or sham-operation. Nephrectomized animals were left untreated or treated with the ACE inhibitor lisinopril in drinking water. In untreated UNx animals systolic blood pressure, serum creatinine, urinary protein and renal synthesis of endothelin-1, evaluated by its urinary excretion, were significantly increased, as compared with control animals with two kidneys. End-stage renal failure developed in all untreated UNx rats that died within 9 to 14 months from UNx. ACE inhibitor significantly reduced systolic blood pressure, completely prevented proteinuria and renal function deterioration, and reduced endothelin-1 excretion. All UNx rats treated with lisinopril were alive 14 months after UNx. These results show that ACE inhibition prevents end-stage renal failure induced by UNx in male MWF/Ztm, and that the beneficial effects of angiotensin II inhibition in this model are related to modulation of renal synthesis of endothelin-1.