Serum and Urinary Fibrin/Fibrinogen Degradation Products in Glomerulonephritis

The serum and urine concentrations of fibrin/fibrinogen degradation products (F.D.P.) were estimated in 172 patients with glomerulonephritis. In each case the diagnosis was established on the basis of clinical, renal histological, and ultrastructural findings. Serum F.D.P. concentrations were often raised in all types of glomerulonephritis, though more consistently in active proliferative forms. The urinary concentration provided a reliable and sensitive index of activity, progression, and natural history in proliferative glomerulonephritis. In these forms the urinary F.D.P. content was thought to reflect predominantly lysis of intraglomerular fibrin deposits. In minimal lesion and membranous glomerulonephritis low but abnormal concentrations of urinary F.D.P. were consistently found. It is suggested that in these cases the products are derived from limited proteolysis of fibrinogen filtered through an abnormally permeable basement membrane.Daily measurement of urinary F.D.P. concentration is of potential value in the differential diagnosis of patients with glomerulonephritis and at the same time provides a sensitive assessment of the activity and natural history of proliferative disease.     

Origin of urinary fibrin/fibrinogen degradation products in glomerulonephritis.

To elucidate the origin of the fibrin/fibrinogen degradation products (F.D.P.) occurring in the urine in glomerulonephritis 28 patients with glomerulonephritis were examined for renal fibrinolytic activity, F.D.P. in urine and serum, and blood fibrinolytic activators and blood fibrinolytic activators and inhibitors. Unlike the glomerful of healthy kidneys, which were fibrinolyticly inactive, those of kidneys with glomerulonephritis constantly showed fibrinolytic activity. The presence or absence of fibrin in the glomeruli was almost always accompanied by, respectively, the presence or absence of urinary F.D.P., which suggested a renal origin of urinary F.D.P. in glomerulonephritis. The low fibrinolytic activity of the blood and the absence of F.D.P. in the serum of these patients make it unlikely that the urinary F.D.P. in glomerulonephritis result from glomerular filtration.     

Serial Estimation of Urinary Fibrin/Fibrinogen Degradation Products in Kidney Transplantation

The urinary excretion of fibrin/fibrinogen degradation products (F.D.P.) of 81 human cadaver kidney transplants has been measured serially by the techniques of tanned red cell haemagglutination inhibition immunoassay and immunonephelometry. Acute rejection episodes in functioning transplants have been associated with increased F.D.P. excretion which in 80% of cases has preceded clinical diagnosis by periods of one to seven days. Recovery from these episodes has been associated with a rapid fall of F.D.P. excretion to undetectable levels. The level of F.D.P. excretion during a rejection episode is a guide to its ultimate outcome. Irreversibly rejected kidneys excrete high levels of F.D.P. for long periods. Viable kidney transplants with prolonged oliguric phases can be distinguished, while still oliguric, from rejected kidneys by their low F.D.P. excretion. F.D.P. cannot usually be detected in the urine of well-functioning transplants. Episodes of raised F.D.P. excretion in the absence of acute clinical rejection, however, occur occasionally and may be associated with permanent impairment of renal function.     

Urinary Fibrinogen Derivative Excretion and Intraglomerular Fibrin Deposition in Glomerulonephritis

The relations between glomerular fibrin deposition, urinary excretion of fibrinogen derivatives (F.D.), and proteinuria were explored in 81 patients with glomerulonephritis. A positive correlation existed between proteinuria and F.D. excretion even when no fibrin could be detected in the glomerulus. In two patients with tubular proteinuria F.D. excretion was also raised, suggesting that tubular reabsorption or catabolism of F.D. or both normally occur.Disproportionately high titres of F.D. were observed when fibrin was deposited in an extracapillary site, but mesangial fibrin deposition was not accompanied by a higher excretion of F.D. than that observed in patients in whom intraglomerular fibrin was not detected. These observations suggest that the immunofluorescent findings on renal biopsies should be the major criteria on which a trial of anticoagulants in proliferative glomerulonephritis might be instituted and that measurement of urinary F.D. is likely to be of value in monitoring therapy in patients with extracapillary fibrin deposition.     

Modification by Drugs of Urinary Fibrin Fibrinogen Degradation Products in Glomerulonephritis

Treatment with indomethacin, aspirin, or prednisone has been shown to reduce urinary fibrin/fibrinogen degradation products (F.D.P.) in approximately two-thirds of patients with proliferative glomerulonephritis. This reduction which is dose-dependent for prednisone but not for indomethacin or aspirin in the range of doses used occurs within two to three days of beginning treatment and is thought to result from decreased intraglomerular fibrin deposition rather than alteration of glomerular permeability to F.D.P. In patients who responded in this manner treatment was associated with reductions in the degree of proteinuria and maintenance or improvement in renal function.     

Reduced urinary excretion of sulfated polysaccharides in diabetic rats

The aim of the present study was to further understand the changes in renal filtration that occur in the early stages of diabetes mellitus. Diabetes was induced in male Wistar rats by a single injection of streptozotocin. Glycemia, body weight, 24-h urine volume and urinary excretion of creatinine, protein and glycosaminoglycans were measured 10 and 30 days after diabetes induction. All the diabetic animals used in the present study were hyperglycemic, did not gain weight, and presented proteinuria and creatinine hyperfiltration. In contrast, the glycosaminoglycan excretion decreased. Dextran sulfates of different molecular weights (6.0 to 11.5 kDa) were administered to the diabetic rats, and to age-matched, sham-treated controls. Most of the dextran sulfate was excreted during the first 24 h, and the amounts excreted in the urine were inversely proportional to the dextran sulfate molecular weight for all groups. Nevertheless, diabetic rats excreted less and accumulated more dextran sulfate in kidney and liver, as compared to controls. These differences, which were observed only for the dextran sulfates of higher molecular weights (>7 kDa), increased with the duration of diabetes. Our findings suggest differential renal processing mechanisms for proteins and sulfated polysaccharides, with the possible involvement of kidney cells.     

Urinary Excretion of C3 Antigen in Glomerulonephritis

C3 and fibrin degradation products (F.D.P.) have been measured in early morning urine samples from 38 normal people and 123 patients with glomerulonephritis. Normal urine contained less than 0·3 μg of either antigen per ml. C3 and F.D.P. were both detected in the urine of many patients with glomerulonephritis. Levels above 1 μg/ml were exceptional in patients with “minimal change,” and the highest excretion of both antigens occurred in mesangiocapillary glomerulonephritis, membranous nephropathy, and focal glomerulosclerosis.Both C3 and F.D.P. excretion showed considerable variation with time, with parellel fluctuations in the two antigens. These fluctuations did not depend on the total protein leakage and suggest that the complement and clotting sequence are closely related in these glomerular disorders.     

A Preliminary Immunologic Study of Urinary Proteins: The Questionable Value of Protein Clearances in Kidney Disease

The clearances of seven different proteins were measured by a quantitative immunodiffusion technique in 15 patients with proteinuria. All urines were also studied by immunoelectrophoresis.The renal histology was evaluated in each case, and no correlation was found between histologic changes and the urinary protein excretion. This observation was confirmed by both immunodiffusion and immunoelectrophoretic techniques. No specific urinary protein excretion pattern was found in six patients with systemic lupus erythematosus.High-molecular-weight proteins were rarely found in urine, even when the glomerular basement membrane was definitely thickened. Low-molecular-weight proteins were often observed, but their clearances were variable. The results do not support the suggestion that protein clearances are valuable diagnostic and prognostic tools in renal diseases. They also do not support the view that glomerular filtration is the sole factor responsible for the final patterns of urinary proteins; tubular reabsorption is probably another important factor.     

Effect of indomethacin on proteinuria in rats with autologous immune complex nephropathy

Although non-steroidal anti-inflammatory agents have been used to reduce levels of urinary protein excretion in patients with the nephrotic syndrome, the general usefulness of these drugs in proteinuric states remains unclear. The present study was designed to confirm the efficacy and to investigate some of the mechanism/s of action of non-steroidal anti-inflammatory agents in animals with proteinuria as the result of a single form experimental renal disease. Autologous immune complex nephropathy was produced in groups of Lewis rats by the administration of autologous tubular F×1A antigen. After marked proteinuria developed, indomethacin (8 mg/kg/day) was administered orally to one group of animals for five days while a control group received only vehicle. The level of urinary protein excretion in the indomethacin treated animals was 420 ± 198 mg/day compared to a level of 1180 ± 306 seen in the untreated animals (p < 0.05). When the indomethacin-treated and control animals were compared, the reduction in proteinuria could not be found to be associated with a change in the glomerular filtration rate, urine electrolyte or osmolar excretion rates, electron microscopic appearance of the glomerular basement membrane, or a change in the glomerular permeability to neutral dextran. Treatment of animals with either sodium salicylate or lower doses of indomethacin (both of which resulted also in significant falls in urinary prostaglandin E excretion rates) failed to reduce the levels of proteinuria. Thus, indomethacin was capable of reducing the levels of protein excretion in rats with autologous immune complex nephropathy although the mechanism of action of this agent remains unclear.     

Effect of indomethacin on proteinuria in rats with autologous immune complex nephropathy

Although non-steroidal anti-inflammatory agents have been used to reduce levels of urinary protein excretion in patients with the nephrotic syndrome, the general usefulness of these drugs in proteinuric states remains unclear. The present study was designed to confirm the efficacy and to investigate some of the mechanism/s of action of non-steroidal anti-inflammatory agents in animals with proteinuria as the result of a single form experimental renal disease. Autologous immune complex nephropathy was produced in groups of Lewis rats by the administration of autologous tubular Fx1A antigen. After marked proteinuria developed, indomethacin (8 mg/kg/day) was administered orally to one group of animals for five days while a control group received only vehicle. The level of urinary protein excretion in the indomethacin treated animals was 420 +/- 198 mg/day compared to a level of 1180 +/- 306 seen in the untreated animals (p less than 0.05). When the indomethacin-treated and control animals were compared, the reduction in proteinuria could not be found to be associated with a change in the glomerular filtration rate, urine electrolyte or osmolar excretion rates, electron microscopic appearance of the glomerular basement membrane, or a change in the glomerular permeability to neutral dextran. Treatment of animals with either sodium salicylate or lower does of indomethacin (both of which resulted also in significant falls in urinary prostaglandin E excretion rates) failed to reduce the levels of proteinuria. Thus, indomethacin was capable of reducing the levels of protein excretion in rats with autologous immune complex nephropathy although the mechanism of action of this agent remains unclear.     

Urinary excretion of unconjugated and conjugated 3,5-diiodothyronine

A radioimmunoassay for the estimation of 3,5-diiodothyronine (3,5-T2) in human urine has been established. The urinary excretion of both glucuronide and sulfate conjugates of 3,5-T2 were estimated after enzymatic deconjugation. In 19 healthy controls the median excretion of unconjugated 3,5-T2 was 276 pmol/d, whereas the median excretion of glucuronidated and sulfated 3,5-T2 in 7 healthy subjects was 448 and 451 pmol/d, respectively. The median excretion of 154 pmol/d in 9 hypothyroid patients did not differ from that found in controls. In contrast 12 patients with hyperthyroidism had an enhanced excretion, 1312 pmol/d (P less than 0.01). Compared with previous data on the daily degradation of 3,5-T2, it is concluded that approximately one-sixth of degradated 3,5-T2 is excreted in the urine.     

Serum and Urine Fibrinogen-Fibrin-related Antigen (F.R.-Antigen) Levels in Renal Disease

The concentration of serum fibrinogen-fibrin-related antigen (F.R.-antigen) was measured in a group of 142 patients with various renal disorders, in 38 of whom urine F.R.-antigen was also estimated. Raised serum F.R.-antigen levels were present in 48% of the patients, with no particular preponderance in any diagnostic category apart from acute reversible intrinsic renal failure in which high levels were invariably present. Significantly-raised serum levels were also present in the patients with microangiopathic haemolytic anaemia and in those with the more severe degrees of renal impairment. Urine F.R.-antigen was increased in 34 of the 38 patients. The amount of F.R.-antigen in the urine correlated with the degree of proteinuria but not with the serum F.R.-antigen levels. The evidence relating to intravascular coagulation in renal disease is reviewed, and it is suggested that there is a high incidence of localized fibrinogen or fibrin degradation in the kidney, which is related more to factors such as the presence of uraemia and microangiopathic haemolytic anaemia rather than to the diagnostic category.     

Comparison of the urinary excretion time courses of pyrene-1,6-dione, pyrene-1,8-dione and 1-hydroxypyrene in rats intravenously exposed to pyrene.

The urinary excretion time courses of pyrene-1,6-dione (P16D), pyrene-1,8-dione (P18D) and 1-hydroxypyrene (1-OHP) were compared in Sprague-Dawley and Wistar rats. Groups of five male rats, of about 200 g of body weight, were injected intravenously with 0.05, 0.5, 5 and 50 micromol pyrene kg-1 of body weight. Urine was collected at 2, 4, 6, 8, 10, 12, 18, 24, 30, 42 and 48 h post-dosing. Pyrene metabolites were measured by high-performance liquid chromatography (HPLC)/fluorescence after enzymatic hydrolysis of the glucurono- and sulfo-conjugates, extraction on Sep-Pak C18 cartridges and, for the analysis of dione metabolites, derivatization to stable diacetoxypyrene molecules. Over the 48-h sampling period, on average 17.4-25.6% of the injected pyrene was excreted overall as P16D, 6.4-8.8% as P18D and 0.6-0.8% as 1-OHP in the urine of Sprague-Dawley rats. By comparison, on average 10.3-14.7% of the intravenous pyrene dose was recovered as P16D, 4.8-6.4% as P18D and 0.3-0.4% as 1-OHP in the urine of Wistar rats. In both strains of rats there was no clear effect of the dose on the 0-48-h cumulative urinary excretion of P18D and 1-OHP over the entire dose range, while the percentage of dose recovered overall as P16D in urine at the highest dose (50 micromol kg-1) was statistically lower than at the other doses. The 0-48-h cumulative percentage of pyrene dose excreted as metabolites in the urine of Sprague-Dawley rats was also significantly higher than in Wistar rats (p<0.01) exposed under identical conditions. As for the urinary excretion-time courses of the different metabolites, for a given dose and strain of rats, excretion curves of P16D, P18D and 1-OHP generally evolved in parallel. There was also no clear effect of the dose on the excretion rate, thus half-life, of pyrene metabolites, except for P16D in Sprague-Dawley rats at the highest dose where elimination tended to be slower compared with the other doses (p<0.01). The average first-order elimination half-life of P16D, P18D and 1-OHP was 4.0, 5.7 and 4.1 h, respectively, in Sprague-Dawley rats, and 5.1, 6.1 and 5.1 h, respectively, in Wistar rats (all doses combined but excluding the highest dose for P16D). This study showed the relative importance of metabolic pathways leading to diones compared with 1-OHP. These dioxygenated metabolites appear to be interesting biomarkers of pyrene exposure at environmentally and occupationally relevant doses. Their adequacy as biomarkers of human exposure has yet to be confirmed.     

Human glomerular basement membrane. Antigenic determinants in human urine

Antisera against particulate human glomerular basement membrane prepared from cadaver kidneys were raised in rabbits. It was shown that both normal individuals and patients with glomerular and tubular diseases excrete in their urine several antigens reactive with these antibodies. One antigen crossreacted immunologically with an antigen from human glomerular basement membrane while several others did not. One of the urinary antigens and the antigen crossreacting with the basement membrane were separated from the others by ion exchange chromatography and gel filtration, respectively.The pattern of antigen excretion differed depending on the underlying renal disease but the multitude of different antigens detected complicates the interpretation of the patterns of excretion in different diseases.     

Human glomerular basement membrane. Antigenic determinants in human urine.

Antisera against particulate human glomerular basement membrane prepared from cadaver kidneys were raised in rabbits. It was shown that both normal individuals and patients with glomerular and tubular diseases excrete in their urine several antigens reactive with these antibodies. One antigen crossreacted immunologically with an antigen from human glomerular basement membrane while several others did not. One of the urinary antigens and the antigen crossreacting with the basement membrane were separated from the others by ion exchange chromatography and gel filtration, respectively. The pattern of anttigen excretion differed depending on the underlying renal disease but the multitude of different antigens detected complicates the interpretation of the patterns of excretion in different diseases.     

Inhibitory effect of resveratrol on proteinuria, hypoalbuminemia and hyperlipidemia in nephritic rats.

The effect of resveratrol, a polyphenolic compound present in grapes and other plants, on proteinuria, hypoalbuminemia and hyperlipidemia was studied in rats with glomerulonephritis. The nephritis was induced by an intravenous injection of anti-rat kidney glomerular basement membrane rabbit antiserum. Nephritic rats were given oral intubation of resveratrol (5 mg/day/100 g body weight) for 14 days, while control nephritic rats as well as normal ones were similarly given vehicle alone. By resveratrol treatment, enlargement in liver and kidney due to nephritis induction was significantly reduced, together with partial restoration of nephritis-induced reduction in body weight gain. Both proteinuria and hypoalbuminemia, characteristic symptoms to nephrotic syndrome, were significantly remedied, that is, urinary protein excretion was suppressed and serum albumin concentration was increased by resveratrol treatment. Resveratrol also suppressed significantly hyperlipidemia incident to nephritis, the hypotriglyceridemic action being more prominent than the hypocholesterolemic one. From these results, resveratrol is suggested to be a potent anti-glomerulonephritic food factor capable of suppressing proteinuria, hypoalbuminemia and hyperlipidemia at the same time.     

阿霉素肾病大鼠尿液糖胺聚糖与尿液蛋白含量的相关性

目的探讨阿霉素肾病大鼠疾病进展过程中尿液糖胺聚糖含量的变化及其与尿蛋白的关系。方法采用一次性尾静脉注射阿霉素6mg/kg制作肾病综合征大鼠模型,第1、2、3、4、6周分别收集大鼠24h尿液测定尿糖胺聚糖和尿蛋白含量。43d后结束实验取血及肾脏,检测血生化,观察肾组织病理改变。结果第2、3、4、6周与正常对照组比较,阿霉素肾病大鼠24h尿蛋白排泄量呈进行性明显上升趋势;造模43d后模型组血清白蛋白含量显著下降,总胆固醇和甘油三酯含量显著升高,肾组织病理所见,模型组肾小球系膜区见中度至重度的系膜细胞增殖及基质增生。从第3周开始阿霉素肾病大鼠尿糖胺聚糖浓度显著高于正常组,且与24h尿蛋白排泄量呈正相关关系。第6周尿糖胺聚糖浓度与血清白蛋白浓度负相关,与甘油三酯浓度正相关。结论阿霉素肾病综合征大鼠尿液中糖胺聚糖浓度升高,并与24h尿蛋白排泄、血清白蛋白、甘油三酯浓度显著相关。     

Comparison of the urinary excretion time courses of pyrene-1,6-dione,pyrene-1,8-dione and 1-hydroxypyrene in rats intravenously exposed to pyrene

Abstract

The urinary excretion time courses of pyrene-1,6-dione (P16D), pyrene-1,8-dione (P18D) and 1-hydroxypyrene (1-OHP) were compared in Sprague–Dawley and Wistar rats. Groups of five male rats, of about 200 g of body weight, were injected intravenously with 0.05, 0.5, 5 and 50 µmol pyrene kg^?1 of body weight. Urine was collected at 2, 4, 6, 8, 10, 12, 18, 24, 30, 42 and 48 h post-dosing. Pyrene metabolites were measured by high-performance liquid chromatography (HPLC)/fluorescence after enzymatic hydrolysis of the glucurono- and sulfo-conjugates, extraction on Sep-Pak C18 cartridges and, for the analysis of dione metabolites, derivatization to stable diacetoxypyrene molecules. Over the 48-h sampling period, on average 17.4–25.6% of the injected pyrene was excreted overall as P16D, 6.4–8.8% as P18D and 0.6–0.8% as 1-OHP in the urine of Sprague–Dawley rats. By comparison, on average 10.3–14.7% of the intravenous pyrene dose was recovered as P16D, 4.8–6.4% as P18D and 0.3–0.4% as 1-OHP in the urine of Wistar rats. In both strains of rats there was no clear effect of the dose on the 0–48-h cumulative urinary excretion of P18D and 1-OHP over the entire dose range, while the percentage of dose recovered overall as P16D in urine at the highest dose (50 µmol kg^?1) was statistically lower than at the other doses. The 0–48-h cumulative percentage of pyrene dose excreted as metabolites in the urine of Sprague–Dawley rats was also significantly higher than in Wistar rats (p<0.01) exposed under identical conditions. As for the urinary excretion-time courses of the different metabolites, for a given dose and strain of rats, excretion curves of P16D, P18D and 1-OHP generally evolved in parallel. There was also no clear effect of the dose on the excretion rate, thus half-life, of pyrene metabolites, except for P16D in Sprague–Dawley rats at the highest dose where elimination tended to be slower compared with the other doses (p<0.01). The average first-order elimination half-life of P16D, P18D and 1-OHP was 4.0, 5.7 and 4.1 h, respectively, in Sprague–Dawley rats, and 5.1, 6.1 and 5.1 h, respectively, in Wistar rats (all doses combined but excluding the highest dose for P16D). This study showed the relative importance of metabolic pathways leading to diones compared with 1-OHP. These dioxygenated metabolites appear to be interesting biomarkers of pyrene exposure at environmentally and occupationally relevant doses. Their adequacy as biomarkers of human exposure has yet to be confirmed.     

Species-, sex-, and age-dependent urinary excretion of cauxin, a mammalian carboxylesterase

Domestic cats exhibit physiological proteinuria due to the excretion of cauxin, a carboxylesterase, into the urine. In the present report, we demonstrate that cauxin is excreted in a species-, sex-, and age-dependent manner. Although the cauxin gene is conserved in mammals, including human, mouse, and dog, urinary cauxin was found only in member of the genus Felis and lynx (bobcat, and lynx) and not in other Felidae (genus: Panthera and puma) tested. In mature cats, cauxin excretion was higher in intact males than in castrated males or in intact or spayed females. Daily cauxin excretion decreased immediately after castration. Immunohistochemistry confirmed that cauxin expression in the kidney proximal straight tubules was higher in intact males than in castrated males. Urinary cauxin was detectable by Western blotting in cats older than about 3 months, and its excretion increased with age. In a zymographic esterase assay, urine contained a major cauxin band; by contrast, kidney homogenates contained three major bands, comprising two carboxylesterases and an unidentified esterase, and one minor cauxin band. These results suggest that 1. cauxin excretion is regulated by sex hormones, such as testosterone, 2. cauxin functions as an esterase in the urine rather than in kidney cells, and 3. the decomposition products by cauxin are excreted in a species-, sex-, and age-dependent manner, as is cauxin itself.     

Increased urinary excretion of platelet activating factor in mice with lupus nephritis

Platelet activating factor (PAF) is present in urine from humans and experimental animals in normal conditions. Very little is known about changes in PAF urinary excretion under pathologic conditions and no data are available about the origin of PAF in the urine. In the present study we explored the possibility that immunologic renal disease is associated with an increase in PAF urinary excretion using gas chromatography-mass spectrometry technique. To clarify the renal or extrarenal origin of urinary PAF we evaluated whether exogenously administered PAF (1-[1', 2'-3H]alkyl) is filtered through the glomerulus and excreted in the urine. The results show that: 1) urine from mice with lupus nephritis in the early phase of the disease contained amounts of PAF comparable to those excreted in normal mouse urine, 2) PAF levels increased when animals started to develop high grade proteinuria, 3) after intravenous injection of [3H] PAF in nephritic mice, a negligible amount of [3H] ether lipid, corresponding to [3H]1-alkyl -2-acyl-3-phosphocholine (alkyl-2-acyl-GPC), was recovered from the 24 h urine extract.