The Long-Term Study of Urinary Biomarkers of Renal Injury in Spontaneously Hypertensive Rats.

BACKGROUND: The age-related increase in blood pressure in spontaneously hypertensive rats (SHRs) is associated to cardiac hypertrophy, heart failure, and renal injury. Here, we investigated for the first time the urinary enzymatic activities of glutamil aminopeptidase (GluAp), alanyl aminopeptidase (AlaAp), dipeptidyl peptidase-4 (DPP4), and Klotho urinary levels, proteins that are strongly expressed in the kidney, as early biomarkers of renal injury in SHRs. METHODS: Male SHR and Wistar Kyoto (WKY) rats were studied from 2 to 8 months old. Systolic blood pressure (SBP), the heart rate (HR), metabolic variables, and urinary markers were measured monthly. At the end of the study, a histopathological evaluation of the kidney was performed. RESULTS: Kidneys of SHR did not develop signs of relevant histopathological changes, but showed increased glomerular area and cellularity. Plasma creatinine was decreased, and creatinine clearance was augmented in SHR at the end of the study. Urinary excretion of Klotho was higher in SHR at 5 and 8 months old, whereas plasma Klotho levels were similar to WKY. GluAp, AlaAp, and DPP4 urinary activities were increased in SHR throughout the time-course study. A positive correlation between glomerular area and cellularity with creatinine clearance was observed. Urinary GluAp, AlaAp, DPP4, and Klotho showed positive correlations with SBP. CONCLUSIONS: GluAp, AlaAp, DPP4, and Klotho in the urine are useful tools for the evaluation of renal damage at early stages, before the whole histopathological and biochemical manifestations of renal disease are established. Moreover, these observations may represent a novel and noninvasive diagnostic approach to assess the evolution of kidney function in hypertension and other chronic diseases.

Multiplex Optical Urinalysis for Early Detection of Drug-Induced Kidney Injury.

Drug-induced kidney injury (DIKI) is a significant contributor of both acute and chronic kidney injury and remains a major concern in drug development and clinical care. However, current clinical diagnostic methods often fail to accurately and timely detect nephrotoxicity. This study reports the development of activatable molecular urinary reporters (MURs) that are able to specifically detect urinary biomarkers including γ-glutamyl transferase (GGT), alanine aminopeptidase (AAP), and N-acetyl-ß-d-glucosaminidase (NAG). By virtue of their discrete absorption and emission properties, the mixture of MURs can serve as a cocktail sensor for multiplex optical urinalysis in the mouse models of drug-induced acute kidney injury (AKI) and chronic kidney disease (CKD). The MURs cocktail not only detects nephrotoxicity earlier than the tested clinical diagnostic methods in drug-induced AKI and CKD mice models, but also possesses a higher diagnostic accuracy. Therefore, MURs hold great promise for detection of kidney function in both preclinical drug screening and clinical settings.

BIOMARKERS OF RENAL INJURY RISK IN CHILDREN WITH PYELONEPHRITIS.

The most common cause of fever in case of anomalies of the urinary system is pyelonephritis (PN). Despite the fact that an intensive search for informative clinical and laboratory markers of PN in children is being conducted in recent years, this problem remains unresolved. Objective - to examine the content of organ-specific enzymes (neutral α-glucosidase (NAG), L-alanine aminopeptidase (AAP), γ-glutamyltranspeptidase (GGTP) in urine and galectin 3 (Gal -3), C-reactive protein (CPR) in blood serum. A prospective, comprehensive clinical and laboratory-instrumental examination was performed in 75 children under the age of 1. The activity of organ-specific enzymes (NAG, AAP, GGTP) in urine and CPR, Gal-3 in the serum of blood were estimated as markers of proximal tubules' damage. The majority (62.99 ± 5.33%) of hospitalized children with febrile temperature and urine changes were diagnosed with PN, which often arose with underlying congenital malformations of the urinary tract. Among children with PN underlaying with VUR, the II and III grades of activity were significantly more frequent. An increase of the level of the enzymes in the urine is observed in the active phase of PN, which correlated with the level of leukocyturia and the level of CRP. During the inactive phase of PN with VUR, the level of enzymes was also higher than the one in children with PN without VUR. High values of Gal-3 were detected in case of underlying VUR, which increased together with increased activity and duration of the inflammatory process in kidneys and correlated with the level of CRP. The Gal-3 can be used for an early diagnosis of fibrotic changes of the renal parenchyma in adolescent children with PN and underlying VUR.

Ultrasensitive Detection of Aminopeptidase N Activity in Urine and Cells with a Ratiometric Fluorescence Probe.

An ultrasensitive ratiometric fluorescent probe (CVN) has been designed and synthesized by incorporating alanine into the cresyl violet fluorophore. The probe shows ratiometric fluorescence response toward aminopeptidase N (APN) through the increase of fluorescent intensity ratio of 626/575 nm. The sensitivity of the probe is ultrahigh with a detection limit of 33 pg/mL, which can quantify the contents of APN in 500-fold diluted human urine samples. Furthermore, by using ratiometric fluorescence imaging, the probe reveals significantly higher contents of APN in HepG2 cells than those in LO2 cells, which has been further used to distinguish these two types of cells in mixed cocultures. The probe could be of great importance for the APN-related disease diagnosis and pathophysiology elucidation.

Urinary Lysosomal Enzyme Activities and Albuminuria in Ghanaian Patients with Type 2 Diabetes Mellitus.

Renal tubular lysosomal enzyme activities like alanine aminopeptidase (AAP) and N-acetyl-ß-D-glucosaminidase (NAG) have been shown to increase in patients developing diabetic nephropathy and nephrosclerosis. This study aimed to determine the activities of N-acetyl-ß-D-glucosaminidase and alanine aminopeptidase and albumin concentration in urine samples of patients with type 2 diabetes. One hundred and thirty (65 type 2 diabetic and 65 nondiabetic) subjects participated in this study. Blood samples were drawn for measurements of fasting blood glucose, albumin (Alb), lipids, and creatinine (Cr). Early morning spot urine samples were also collected for activities of alanine aminopeptidase (AAP), N-acetyl-ß-D-glucosaminidase (NAG), and concentration of albumin (U-Alb) and creatinine (U-Cr). Both NAG/Cr and AAP/Cr were significantly increased in diabetic subjects compared to controls (p < 0.001). There was positive correlation between NAG/Cr and Alb/Cr (r = 0.49, p < 0.001) and between NAG/Cr and serum creatinine (r = 0.441, p < 0.001). A negative correlation was found between NAG/Cr and eGFR (r = -0.432, p < 0.05). 9.3% and 12% of diabetics with normoalbuminuria had elevated levels of AAP/Cr and NAG/Cr, respectively. We conclude that measuring the urinary enzymes activities (NAG/Cr and AAP/Cr) could be useful as a biomarker of early renal involvement in diabetic complications.

Urinary excretion of brush-border enzymes of the proximal renal tubules in pregnant women with hypertensive disorders.

OBJECTIVES: The aim of our study was to evaluate urinary excretion of three brush border enzymes: gamma-glutamyl transferase, alanine aminopeptidase, and leucyl aminopeptidase in pregnant women with various types of hypertensive disorders. MATERIAL AND METHODS: The study included 120 pregnant women, further subdivided into four groups: 41 women at ≥ 20 weeks gestation with gestational hypertension, 28 women > 20 weeks of pregnancy with preeclampsia, 21 women with chronic hypertension identified > 20 weeks of pregnancy and 30 healthy pregnant controls. RESULTS: No significant differences in urinary levels of all three of the brush border enzymes were found between the groups. Also, there was no correlation between enzyme concentration in the urine and blood pressure values in any of the analyzed groups of pregnant women. CONCLUSIONS: The obtained results suggest no damage to the brush border of the proximal kidney tubules in the early stages of disorders associated with increased blood pressure during pregnancy.

Profilin 1 is a potential biomarker for bladder cancer aggressiveness.

Of the most important clinical needs for bladder cancer (BC) management is the identification of biomarkers for disease aggressiveness. Urine is a "gold mine" for biomarker discovery, nevertheless, with multiple proteins being in low amounts, urine proteomics becomes challenging. In the present study we applied a fractionation strategy of urinary proteins based on the use of immobilized metal affinity chromatography for the discovery of biomarkers for aggressive BC. Urine samples from patients with non invasive (two pools) and invasive (two pools) BC were subjected to immobilized metal affinity chromatography fractionation and eluted proteins analyzed by 1D-SDS-PAGE, band excision and liquid chromatography tandem MS. Among the identified proteins, multiple corresponded to proteins with affinity for metals and/or reported to be phosphorylated and included proteins with demonstrated association with BC such as MMP9, fibrinogen forms, and clusterin. In agreement to the immobilized metal affinity chromatography results, aminopeptidase N, profilin 1, and myeloblastin were further found to be differentially expressed in urine from patients with invasive compared with non invasive BC and benign controls, by Western blot or Elisa analysis, nevertheless exhibiting high interindividual variability. By tissue microarray analysis, profilin 1 was found to have a marked decrease of expression in the epithelial cells of the invasive (T2+) versus high risk non invasive (T1G3) tumors with occasional expression in stroma; importantly, this pattern strongly correlated with poor prognosis and increased mortality. The functional relevance of profilin 1 was investigated in the T24 BC cells where blockage of the protein by the use of antibodies resulted in decreased cell motility with concomitant decrease in actin polymerization. Collectively, our study involves the application of a fractionation method of urinary proteins and as one main result of this analysis reveals the association of profilin 1 with BC paving the way for its further investigation in BC stratification.

[Activity of alanine aminopeptidase in blood and in urine of smoking and non-smoking smelters]. / Aktywnosc alanyloaminopeptydazy we krwi i moczu palacych i niepalacych hutników.

The human body is constantly exposed to xenobiotics. This will include exogenous substances from environmental pollution such as heavy metals and lifestyle such as smoking, which may lead to impaired functioning of many organs. The liver and kidney are the critical organs in the case of a long-term occupational or environmental exposure to heavy metals and tobacco smoke. In diagnostics of liver and kidney damage useful are the methods which determine the activity of enzymes such as alanine aminopeptidase (AAP). AAP is a marker for early detection of acute kidney damage, and presence of AAP derive mainly from proximal tubular brush-border. Activity of AAP in urine allows to assess the damage resulting from the nephrotoxic exposure to heavy metals. In the serum AAP is mainly from hepatic. Activity of AAP may be useful to identify liver cancer. The investigation was shown, that AAP activity in the blood is used to detect hepatic cholestasis and congestive jaundice. The aim of present study was to assess the influence of occupational exposure of copper-foundry workers to heavy metals (arsenic, cadmium, lead) on activity of alanine aminopeptidase in blood and urine. The investigations were performed in blood and urine of 166 subjects: 101 male copper smelters and 65 non-exposed male subjects. The study protocol was approved by Local Bioethics Committee of Wroclaw Medical University (KB No: 469/2008). The data on smoking which had been obtained from a direct personal interview were verified by determination of serum cotinine concentrations. Biological material collected from the control group and smelters was divided into subgroups of nonsmokers and smokers. The concentrations of lead and cadmium were determined in whole blood, whilst the level of arsenic and cadmium were determined in urine using FAAS method (Flame Atomic Absorption Spectrometry) in the acetylate flame on the SOLAAR M6. The activity of AA was determined in blood and in urine. The results showed a 9-fold increase in the concentration of lead and 10-fold elevation of arsenic level in all groups of smelters in comparison to the control group. The highest cadmium, lead and arsenic concentrations were observed in blood and urine of smoking smelters. We have observed a significant increase in the concentrations of lead and cadmium in blood of smoking persons from control group in comparison to the non-smoking persons from this group, which suggest, that tobacco smoking increase the heavy metals concentrations in the organisms. Occupational exposure to heavy metals resulted in an increase of AAP activity in blood and urine of all groups of smelters in comparison to corresponding control groups. The highest value of AAP was observed in serum and urine of smoking smelters. Tobacco smoke also increases the AAP activity the blood and urine of smoking smelters and control group compared to the non-smoking smelters and nonsmoking control group, appropriate. The study was shown that occupational exposure to heavy metals and tobacco.

Potassium dichromate-induced changes on urinary-specific activities of gamma-glutamyl transpeptidase and alanine aminopeptidase enzymes.

It has been reported that potassium dichromate-induced nephrotoxicity is evidenced by diminution in creatinine clearance, increase in urinary protein, and structural damage to the proximal tubules. Damage to tissue often leads to the release of enzymes from the injured cells into the extracellular fluids. The aim of this study was to establish whether potassium dichromate induces changes in the urinary-specific activities of gamma-glutamyl transpeptidase and alanine aminopeptidase enzymes. Our results show that the administration of a single intraperitoneal dose of potassium dichromate decreased the activity of such enzymes in urine.

An automated assay of urinary alanine aminopeptidase activity.

BACKGROUND: Urinary enzymes, including the brush border enzyme alanine aminopeptidase (AAP), are reliable biomarkers of nephrotoxicity and represent early indicators of tubular damage. The aim of the present study was to develop and validate an automated urinary AAP activity assay. METHODS AND RESULTS: For this purpose, we adapted a photometric test using the substrate L-alanine-4-nitroanilide to a dedicated clinical chemistry analyser. Due to the unavailability of calibrators with established AAP activity, we assessed the AAP activity of a commercially available control material using the photometric test. This material was subsequently employed as a calibrator for the automated assay. Quality assurance was accomplished with independent control materials. A fast gel filtration step of urine samples using Sephadex G50 was demonstrated to be necessary before AAP analysis to avoid underestimation of enzyme activity due to ammonia and amino acids. We compared the automated assay with a manual photometric assay and obtained excellent correlation between both methods (r2=0.946, n=50). CONCLUSIONS: We conclude that the newly developed automated assay represents a user-friendly and analytical tool to determine urinary AAP activity in a medium- to high-throughput laboratory. Potential applications include clinical diagnostic work and toxicological studies.

Vancomycin-induced nephrotoxicity in rats: is enzyme elevation a consistent finding in tubular injury?

BACKGROUND: Measurement of urinary enzymes facilitates early detection of acute renal impairment. Since in the case of vancomycin-induced nephrotoxicity, there are different findings for the enzyme N-acetyl-beta-D-glucosaminidase (NAG) in various studies, we decided to measure 3 other important urinary enzymes -- gamma-glutamyl-transferase (GGT), alanine aminopeptidase (AAP) and lactate dehydrogenase (LDH) -- in nephrotoxic rats. METHODS: Male rats were given intraperitoneal injections of vancomycin (VAN) in doses of 50, 100, 200 and 400 mg/kg or normal saline every 12 hours for 7 days. After the 14th injection, the animals were placed in metabolic cages to collect urine samples. RESULTS: All animals receiving 400 mg/kg VAN died before completion of treatment course. The nephrotoxicity was completely dose-dependent according to pathologic findings. The major insults were in tubules, resembling acute tubular necrosis. GGT, AAP and LDH activity was measured in urine and corrected by dividing it by urinary creatinine (Cr) concentration. LDH activity showed a dose-dependent increase, while GGT and AAP activity decreased in the 200 mg/kg treated group, but only GGT showed a significant difference with controls. Serum urea and Cr and kidney weights were increased and animals' weights were decreased significantly in the 200 mg/kg VAN group compared with other groups. CONCLUSION: It seems that pathologic assessment remains the most accurate way to diagnose VAN nephrotoxicity. Changes in urinary enzymes could be not detected in minor tubular injuries; however, LDH appears to be the most sensitive factor. In multiple-dose studies, activity of AAP and GGT seems not to be a reliable index of nephrotoxicity.

Association of glomerular and tubular dysfunction with glycaemic control, lipid, lipoprotein, apolipoprotein and antioxidant status in type 2 diabetes mellitus.

INTRODUCTION: This study was conducted to investigate the relationship of glomerular and tubular dysfunctions with glycaemic control, lipid, lipoprotein, apolipoproteins and antioxidant status in 72 patients with type 2 diabetes mellitus. METHODS: Urine albumin concentration was measured by immunoturbidimetric and urine N-acetyl-beta-D-glucosaminidase (NAG) and alanine aminopeptidase (AAP) activities with colorimetric methods. Glycated haemoglobin was measured using affinity chromatography. Erythrocyte glutathione reductase and glutathione peroxidase activities and serum levels of malondialdehyde, lipids, lipoproteins and apolipoproteins were determined in patients with type 2 diabetes mellitus. RESULTS: In univariate regression, urinary albumin excretion, and activities of NAG and AAP were associated with glycaemic control. These glycaemic factors included serum glucose concentrations and glycated haemoglobin. Urinary albumin excretion was also inversely correlated with erythrocyte glutathione peroxidase activity, and positively correlated with erythrocyte glutathione reductase activity. No significant associations were found with serum levels of insulin, lipids, lipoproteins, apolipoproteins, malondialdehyde or blood pressure. In multivariate regression, glycated haemoglobin was the most significant predictor of urinary albumin concentration and with erythrocyte glutathione reductase, whereas only glycated haemoglobin was the independent predictor of tubular dysfunctions. Erythrocyte glutathione peroxidase was not an independent predictor of urinary albumin excretion, after adjusting for glycated haemoglobin, glutathione reductase, systolic blood pressure, diastolic blood pressure and apolipoprotein B. CONCLUSION: In type 2 diabetes mellitus, both glomerular and tubular dysfunctions are dependent on glycaemic control. Glomerular, but not tubular, dysfunction is also significantly associated with increased glutathione reductase activity.

Effects of aerobic exercise on microalbuminuria and enzymuria in type 2 diabetic patients.

Increased urinary albumin excretion is a strong predictor for the development of overt diabetic nephropathy and overall cardiovascular morbidity and mortality in patients with type 2 diabetes. In a previous study, regular aerobic physical activity in overweight/obese patients with type 2 diabetes mellitus was found to have significant beneficial effects on glycemic control, insulin resistance, cardiovascular risk factors, and oxidative stress. The aim of the present study was to investigate the effects of aerobic exercise in the same cohort of type 2 diabetic patients on urinary albumin excretion, serum levels and urinary excretion of enzymes, tubular damage, and metabolic control markers in type 2 diabetic patients. Changes from baseline to 3 and 6 months of aerobic exercise were assessed for urinary albumin excretion, serum activities, and urinary excretion of N-acetyl-beta-D-glucosaminidase (NAGA), plasma cell glycoprotein 1 (PC-1) and aminopeptidase N (APN), as well as their association with insulin resistance, cardiovascular risk factors, and oxidative stress parameters in 30 male type 2 diabetic patients (aged 54.8 +/- 7.3 years, with a mean BMI of 30.8 +/- 3.0 kg/m2). Microalbuminuria was found in six (20%) diabetic patients at baseline, three of them (10%) after three months, and only one patient (3.33%) at the end of the study period. A significant correlation was found for urinary albumin excretion at baseline both with sulfhydryl-groups and catalase, but not for urinary albumin excretion with MDA and glutathione. The prevalence of microalbuminuria tended to decrease after six months of aerobic exercise in type 2 diabetic patients, independently of any improvement in insulin resistance and oxidative stress parameters. Neither between-group nor within-group changes were found for urinary PC-1, APN, and NAGA activity. Serum NAGA was significantly increased (p < 0.05) over the control level in diabetic patients at baseline, but it decreased to the normal level after six months of exercise. This study has shown that a six-month aerobic exercise, without any change in the medication, tended to decrease microalbuminuria without changing enzymuria. However, further studies are needed not only to confirm those findings, but to elucidate potential mechanisms that would clarify the beneficial effects of exercise.

The effect of 2,3-dihydroxybenzoic acid and tempol in prevention of vancomycin-induced nephrotoxicity in rats.

One of the major adverse effects of vancomycin (VAN) is nephrotoxicity, which the mechanism is not fully understood. However, there is some evidence that oxidative injury could be involved in its pathogenesis. In this study, we examined two antioxidants 4-hydroxyl-2,2,6,6-tetramethylpiperidine-1-oxyl (tempol) a superoxide dismutase mimetic and 2,3-dihydroxybenzoic acid (DHB) an iron chelator in VAN-induced nephrotoxicity in rats. DHB at doses of 50 and 100 mg/kg and tempol at doses of 7.5, 15 and 30 mg/kg were administered subcutaneously to rats 30 min prior to intraperitoneal injection of 200 mg/kg VAN. Drug administrations were done every 12 h for 7 days. In animals which received only VAN, the activity of urinary gamma-glutamyl-transferase (GGT) decreased and the activity of lactate dehydrogenase (LDH) in urine increased significantly compared to controls. Serum urea and creatinine (Cr) concentrations and the weight of animals' kidneys increased and body weights were decreased significantly in this group compared to controls. DHB at both doses normalized the GGT activity, but only at the higher dose restore the LDH activity. Both doses of DHB ameliorated the rise in serum urea and Cr concentrations and improved the changes in kidney and body weights significantly. Tempol did not show any beneficial effects at all. There were marked pathologic changes in tubules of kidneys of VAN treated animals. The tissue injury was prevented by both doses of DHB and there was almost no sign of tubular injury in 100 mg/kg treated group. Tempol in any doses could not prevent the tissue injury and there were significant differences in tissue injury in all tempol treated rats with controls. It seems that VAN-induced nephrotoxicity is at least partly due to free radical formation. Hydroxyl radicals might play a major role in VAN-induced nephrotoxicity, since an iron chelator (DHB) could reverse the adverse effects. However, production of other radicals such as superoxide is also probable.

Combining markers of nephrotoxicity and hepatotoxicity for improved monitoring and detection of chronic alcohol abuse.

BACKGROUND: Most of the commonly used markers of chronic alcohol abuse reflect alcohol hepatotoxicity; however, such abuse is deleterious to the kidneys as well. Combined use of serum markers of liver origin and urinary markers of kidney origin may be of diagnostic advantage. METHODS: The study was performed in 73 male alcoholics undergoing detoxification and 36 male alcoholics who had maintained abstinence for > or =6 weeks. Factor analysis, discriminant analysis and receiver operating characteristic (ROC) analysis were used to assess the discriminative power of two urinary markers of alcohol nephrotoxicity, namely beta-N-acetylhexosaminidase (Hex, EC 3.2.1.52) and alanine aminopeptidase (EC 3.4.11.2), and of three serum markers of alcohol hepatotoxicity, namely aspartate aminotransferase (EC 2.6.1.1), alanine aminotransferase (EC 2.6.1.2) and gamma-glutamyltransferase (GGT, EC 2.3.2.2), and of their quantitative combinations. RESULTS: The discriminative power of the urinary markers matched that of the serum markers. Hex and GGT appeared to be the best for discriminating the study groups. Their combination given by the equation G&H=0.62 x ln(GGT)+0.72 x ln(Hex) showed excellent discriminative ability (ROC area under the curve 0.92) that was significantly higher than that of any single marker in this report, indicating superior diagnostic accuracy of the compound marker. CONCLUSIONS: Kidney-derived urinary markers, particularly Hex, can complement or replace, if necessary, serum markers of chronic alcohol abuse that relate to alcohol hepatotoxicity. The compound marker proposed seems a promising tool for the monitoring and perhaps detection of chronic alcohol abuse and warrants further studies.

Excretion of urinary enzymes in normal pregnancy.

OBJECTIVES: To study the pattern of excretion of enzymes in urine during normal pregnancy. DESIGN AND METHODS: Primigravidae, with uncomplicated pregnancies, were followed up throughout gestation. Urine samples were collected from them and activities of alanine aminopeptidase (AAP), gamma-glutamyl transferase (GGT), acid phosphatase (ACP) and N-acetyl-beta-d-glucosaminidase (NAG) activities in urine were estimated. RESULTS: Small but significant increases were found in the activities of AAP and NAG excreted through the course of pregnancy. The changes seen in excretion of ACP and GGT were not statistically significant. CONCLUSIONS: Changes in excretion of ACP and GGT may be useful indicators of renal dysfunction in pregnancy, as their activities did not vary significantly through the course of normal pregnancy.

[Diagnosis the state of the proximal renal tubular epithelium in patients with coronary heart disease and chronic heart failure].

Renal dysfunction is a common complication of chronic heart failure (CHF). Renal filtration capacity has been evaluated in numerous studies, but there are studies dealing with renal tubular function in patients with coronary heart disease (CHD) concurrent with CHF, which became the subject of the present study. Seventy-nine patients with CHD with different stages of CHF (OCCH, 2002) and 12 healthy individuals were examined. The urinary activity of neutral maltase and L-alanine aminopeptidase was evaluated. The renal tubular dysfunction evaluated by the blood levels on the enzymes was found to increase with the greater severity of CHF.

Oxidative stress and coenzyme Q10 supplementation in renal transplant recipients.

Recently some reports about the oxidative stress in renal transplant recipients have been published. The role of coenzyme Q10 (CoQ10) as radical scavanger is largely known. The aim of our study was to evaluate the protective role of CoQ10 in renal transplant recipients on lipid peroxidation and lipids parameters, as well as its influence on antioxidant enzymes, neutrophils chemiluminescence and urinary enzymes. The study was performed in 11 long term allograft recipients treated additionally with CoQ10 90 mg/day in three doses, 30 mg each for four weeks. The malonyldialdehyde (MDA) and 4-hydroxynonenal (4-HNE), superoxide dismutase (SOD) and glutathione peroxidase (GPx) and the basic parameters of lipid metabolism such as total cholesterol (TC), high and low density lipoproteins (HDL, LDL), triglycerides (TG), atherogenicity indicators [LDL/HDL; (TC-HDL)/HDL] were evaluated. The chemiluminescence of neutrophils (luminol, fLMP-method) were mesured and the activity of N-acetyl-beta-D-glucosaminidase (NAG), alanylaminopeptidase (AAP), elastase, alpha-1-antitrypsin. All parameters were estimated before and after CoQ10 treatment. Statistically significant changes were noticed with the LDL and atherogenicity indicators (p < 0.01) (decrease) as well as HDL level (p < 0.001) (increase). Also the significant decrease of fMLP stimulated PMNL chemiluminescence (p < 0.05) confirms the antioxidative properties of CoQ10. The significant increase of NAG activity (p < 0.05) can't be the result of nephrotoxic effect, because NAG-B is unchanged. Serum concentration of creatinine and cyclosporine A in renal allograft recipients was unchanged after CoQ10 treatment. The presented date shows that further study with CoQ10 treatment in renal transplant in larger numbers and over longer periods should be considered.

Effect of once-daily dosing vs. multiple daily dosing of tobramycin on enzyme markers of nephrotoxicity.

OBJECTIVE: To determine the incidence of nephrotoxicity of once-daily dosing (ODD) and multiple daily dosing (MDD) regimens of tobramycin in critically ill patients. DESIGN: Randomized, prospective clinical trial. SETTING: : Adult intensive care units at two university hospitals. PATIENTS: Fifty-eight critically ill patients with a suspected or documented aerobic Gram-negative infection. INTERVENTIONS: Patients were randomized to receive tobramycin by ODD (7 mg/kg) or MDD. Baseline urine aliquots and 24-hr urine collections were collected on days 3, 7, and 11 during therapy and on days 3, 7, and 11 following discontinuation of therapy for measurement of alanine aminopeptidase (AAP), N-acetyl-beta-d-glucosaminidase (NAG), and creatinine. MEASUREMENTS AND MAIN RESULTS: Fifty-four patients were evaluable (ODD n = 25; MDD n = 29). The groups were similar with regard to demographic and clinical variables. The tobramycin dose was higher in the ODD group compared with the MDD group (425 +/- 122.5 mg vs. 312.8 +/- 116.6 mg, p <.001). Patients in the MDD group received a mean of 3.89 +/- 1.14 mg.kg(-1)day(-1) at intervals of 11.92 +/- 3.12 hrs. In the ODD group, patients had a higher measured creatinine clearance at the end of therapy compared with MDD group (70 +/- 18.6 vs. 64.8 +/- 17.5 mL/min, p =.047). Fewer patients in the ODD group developed nephrotoxicity than the MDD group (5 vs. 12, p =.142). Although there were increases in urinary enzymes in both treatment groups (AAP, 8.7 +/- 2.9 vs. 5.2 +/- 2.1 units/24 hrs, p <.01 MDD vs. ODD; NAG, 14.7 +/- 4.9 vs. 6.8 +/- 3.1, p <.01 MDD vs. ODD), the increases in the ODD group were significantly lower than in the MDD group. CONCLUSIONS: : The ODD tobramycin regimen appeared to be less nephrotoxic than the MDD regimen despite significantly higher doses. Tobramycin administered by ODD may be the preferred dosing method in selected critically ill medical patients to reduce the incidence and extent of renal damage.

Alanine aminopeptidase activity in urine: a new marker of chronic alcohol abuse?

BACKGROUND: The purpose of this study was to evaluate the activity of urinary alanine aminopeptidase (AAP), the enzyme released from the brush border membranes of renal proximal tubules, as a new biological marker of chronic alcohol abuse. METHODS: The AAP activity was assayed and compared between a group of 76 alcoholics undergoing detoxification and a group of 37 alcoholics abstaining from alcohol for at least 6 weeks. In all patients, the enzyme activity was measured both in untreated urine (uAAP) and after removal of endogenous AAP inhibitors by molecular filtration on Sephadex (eAAP). RESULTS: There was a correlation between the uAAP and eAAP activities in both groups of patients (r = 0.61 and r = 0.81 in abstinent alcoholics and in alcoholics undergoing detoxification, respectively), and both the uAAP activity and the eAAP activity were significantly and markedly higher in alcoholics being detoxified than in their abstinent counterparts. As revealed by receiver operating characteristic analysis, the discriminative power of the eAAP activity assay was higher than that of the uAAP activity assay. The area under the corresponding receiver operating characteristic curves was 0.84 +/- 0.04 and 0.78 +/- 0.05 (mean +/- SE), respectively. CONCLUSIONS: The results of this study demonstrate that the assays of urinary AAP activity, which relate to the nephrotoxic effects of alcohol abuse, could be a valuable complement to the other presently used markers of chronic alcohol abuse that are generally based on ethanol hepatotoxicity. Compared with the uAAP activity test, the eAAP activity test is of clear diagnostic advantage.