Pyrrolidine dithiocarbamate reduces alloxan-induced kidney damage by decreasing nox4, inducible nitric oxide synthase, and metalloproteinase-2.

We examined the effect of the NFκB inhibitor pyrrolidine-1-carbodithioic acid (PDTC) on inducible nitric oxide synthase (iNOS), matrix metalloproteinase-2 (MMP-2) activity, and oxidative and inflammatory kidney damage in alloxan-induced diabetes. Two weeks after diabetes induction (alloxan-130 mg/kg), control and diabetic rats received PDTC (100 mg/kg) or vehicle for 8 weeks. Body weight, glycemia, urea, and creatinine were measured. Kidney changes were measured in hematoxylin/eosin sections and ED1 by immunohistochemistry. Kidney thiobarbituric acid reactive substances (TBARS), superoxide anion (O2-), and nitrate/nitrite (NOx) levels, and catalase and superoxide dismutase (SOD) activities were analyzed. Also, kidney nox4 and iNOS expression, and NFkB nuclear translocation were measured by western blot, and MMP-2 by zymography. Glycemia and urea increased in alloxan rats, which were not modified by PDTC treatment. However, PDTC attenuated kidney structural alterations and macrophage infiltration in diabetic rats. While diabetes increased both TBARS and O2- levels, PDTC treatment reduced TBARS in diabetic and O2- in control kidneys. A decrease in NOx levels was found in diabetic kidneys, which was prevented by PDTC. Diabetes reduced catalase activity, and PDTC increased catalase and SOD activities in both control and diabetic kidneys. PDTC treatment reduced MMP-2 activity and iNOS and p65 NFκB nuclear expression found increased in diabetic kidneys. Our results show that the NFκB inhibitor PDTC reduces renal damage through reduction of Nox4, iNOS, macrophages, and MMP-2 in the alloxan-induced diabetic model. These findings suggest that PDTC inhibits alloxan kidney damage via antioxidative and anti-inflammatory mechanisms.

Involvement of cytochrome P450 in cisplatin treatment: implications for toxicity.

PURPOSE: The aim of this study is to evaluate the relationship between the CYP450 enzyme family and cisplatin toxicity. METHODS: This article examined a collection of studies suggesting that CYP450 enzymes may influence cisplatin toxicity. We performed a narrative mini-review. RESULTS: The studies review showed that CYP450 enzymes have an important role in drug-induced hepatotoxicity and nephrotoxicity, mainly CYP2E1 and CYP4A11. The studies also suggested that the cisplatin and CYP2E1 interaction leads to the generation of reactive oxygen species (ROS) and other oxidants resulting in renal injury; and that ROS generated by both the use of cisplatin and by the CYP2E1 increases tissue damage, induces apoptosis, and causes liver failure. CONCLUSIONS: We observed that there is an important relationship between CYP450 and cisplatin, involving increased toxicity. However, the possible mechanisms described for the involvement of CYP450 enzymes in nephrotoxicity and hepatotoxicity induced by cisplatin need to be confirmed by further studies. Therefore, there is a need for a deeper investigation focusing on cisplatin toxicity mediated by CYP450 enzymes, which would undoubtedly contribute to a better understanding of the mechanisms that have been implicated so far.

Effects of treatment with the anti-parasitic drug diminazene aceturate on antioxidant enzymes in rat liver and kidney.

Diminazene aceturate (DA) is the active component of some trypanocidal drugs used for the treatment of animals infected with trypanosomosis and babesiosis. Residues of DA may cause hepatotoxic and nephrotoxic effects. Therefore, the purpose of this study was to investigate the occurrence of oxidative stress, i.e., changes in the antioxidant defense system of rats treated with a single dose of 3.5 mg kg(-1) of DA. All treatments were intramuscularly administered, and evaluations were performed on days 7 and 21 post-treatment (PT). Liver and kidney samples were collected and evaluated by histopathology and oxidative stress parameters (thiobarbituric acid-reactive species, catalase, superoxide dismutase, carbonyl, non-protein thiols, and reduced glutathione). Finally, blood was collected to determine seric DA concentration. Superoxide dismutase (SOD) and catalase (CAT) activities in liver and kidney of rats were dramatically inhibited (p < 0.05) compared to the control group on day 21 PT. This difference is related to the concomitant increase (p < 0.05) in malondialdehyde (MDA) content, which was identified by an increase in thiobarbituric acid-reactive species (TBARS) levels. The carbonyl levels did not differ between groups (p > 0.05). Both non-protein thiols (NPSH) and glutathione (GSH) levels in liver and kidney decreased (p < 0.05) on day 21 PT. Chromatographic analyses showed lower levels of DA on day 21 PT compared to day 7 PT. A negative correlation was observed between DA concentration in serum and lipid peroxidation in liver and kidney tissues on 21 days PT. Histopathology revealed vacuolar degeneration in liver and kidney samples on day 21 PT. Our findings indicate that DA could cause oxidative damage to liver and kidney of rats.

Cecropia pachystachya extract attenuated the renal lesion in 5/6 nephrectomized rats by reducing inflammation and renal arginase activity.

ETHNOPHARMACOLOGICAL RELEVANCE: The plant Cecropia pachystachya Trécul has been used in Brazilian folk medicine to treat hypertension, bladder and kidney inflammation and renal diseases. The aim of this study was to evaluate the potential of the aqueous fraction from the ethanolic extract of Cecropia pachystachya (FCP) in the management of hypertension, inflammation and progressive renal disease in rats submitted to 5/6 nephrectomy. MATERIALS AND METHODS: Thirty male Wistar rats submitted to 5/6 nephrectomy (5/6 NE) were untreated (NE) or treated (NE+FCP) with the FCP (0.5g/kg/day). The treatment started 15 days after surgery, and the rats were followed for a period of 60 days. Systolic blood pressure (SBP) and albuminuria were evaluated from 15-60 days after the surgical procedure. Function and estructural renal changes, TGF-ß (transforming growth factor ß), MCP-1 (monocyte chemoattractant protein-1) and nitric oxide (NO) urinary excretion were analyzed. Expression and activity of the renal enzymes arginase (ARG), angiotensin converting enzyme (ACE), and MAP kinase p-JNK expression also were analyzed. RESULTS: The nephrectomized rats developed progressive albuminuria and increased SBP that was less intense in the treated group. There was a reduction in the glomerular filtration rate (GFR) in the nephrectomized rats, which was attenuated by treatment with FCP extract. The treatment with FCP also attenuated the histological changes, reduced the expression and activity of renal arginase, the number of macrophages (ED-1 positive cells) and the p-JNK expression in the renal cortex of the rats submitted to 5/6 NE. The urinary excretion of TGF-ß was less intense in the treated group and was associated with the reduction of the expression and activity of the renal arginase. CONCLUSIONS: These results suggest that the reduction of renal arginase activity, p-JNK and TGF-ß expression can explain the mechanism by which the treatment with C. pachystachya reduced the inflammation and improved renal function. This study presents the potential use of Cecropia pachystachya in the treatment of chronic renal diseases.

Sex-specific associations of variants in regulatory regions of NADPH oxidase-2 (CYBB) and glutathione peroxidase 4 (GPX4) genes with kidney disease in type 1 diabetes.

Oxidative stress is involved in the pathophysiology of diabetic nephropathy. The superoxide-generating nicotinamide adenine dinucleotide phosphate-oxidase 2 (NOX2, encoded by the CYBB gene) and the antioxidant enzyme glutathione peroxidase 4 (GPX4) play opposing roles in the balance of cellular redox status. In the present study, we investigated associations of single nucleotide polymorphisms (SNPs) in the regulatory regions of CYBB and GPX4 with kidney disease in patients with type 1 diabetes. Two functional SNPs, rs6610650 (CYBB promoter region, chromosome X) and rs713041 (GPX4 3'untranslated region, chromosome 19), were genotyped in 451 patients with type 1 diabetes from a Brazilian cohort (diabetic nephropathy: 44.6%) and in 945 French/Belgian patients with type 1 diabetes from Genesis and GENEDIAB cohorts (diabetic nephropathy: 62.3%). The minor A-allele of CYBB rs6610650 was associated with lower estimated glomerular filtration rate (eGFR) in Brazilian women, and with the prevalence of established/advanced nephropathy in French/Belgian women (odds ratio 1.75, 95% CI 1.11-2.78, p = 0.016). The minor T-allele of GPX4 rs713041 was inversely associated with the prevalence of established/advanced nephropathy in Brazilian men (odds ratio 0.30, 95% CI 0.13-0.68, p = 0.004), and associated with higher eGFR in French/Belgian men. In conclusion, these heterogeneous results suggest that neither CYBB nor GPX4 are major genetic determinants of diabetic nephropathy, but nevertheless, they could modulate in a gender-specific manner the risk for renal disease in patients with type 1 diabetes.

Synergistic effect of uricase blockade plus physiological amounts of fructose-glucose on glomerular hypertension and oxidative stress in rats.

Fructose in sweetened beverages (SB) increases the risk for metabolic and cardiorenal disorders, and these effects are in part mediated by a secondary increment in uric acid (UA). Rodents have an active uricase, thus requiring large doses of fructose to increase plasma UA and to induce metabolic syndrome and renal hemodynamic changes. We therefore hypothesized that the effects of fructose in rats might be enhanced in the setting of uricase inhibition. Four groups of male Sprague-Dawley rats (n = 7/group) were studied during 8 wk: water + vehicle (V), water + oxonic acid (OA; 750 mg/k BW), sweetened beverage (SB; 11% fructose-glucose combination) + V, and SB + OA. Systemic blood pressure, plasma UA, triglycerides (TG), glucose and insulin, glomerular hemodynamics, renal structural damage, renal cortex and liver UA, TG, markers of oxidative stress, mitDNA, fructokinase, and fatty liver synthase protein expressions were evaluated at the end of the experiment. Chronic hyperuricemia and SB induced features of the metabolic syndrome, including hypertension, hyperuricemia, hyperglycemia, and systemic and hepatic TG accumulation. OA alone also induced glomerular hypertension, and SB alone induced insulin resistance. SB + OA induced a combined phenotype including metabolic and renal alterations induced by SB or OA alone and in addition also acted synergistically on systemic and glomerular pressure, plasma glucose, hepatic TG, and oxidative stress. These findings explain why high concentrations of fructose are required to induce greater metabolic changes and renal disease in rats whereas humans, who lack uricase, appear to be much more sensitive to the effects of fructose.

(Na+ + K+)-ATPase is a target for phosphoinositide 3-kinase/protein kinase B and protein kinase C pathways triggered by albumin.

In recent decades, evidence has confirmed the crucial role of albumin in the progression of renal disease. However, the possible role of signaling pathways triggered by physiologic concentrations of albumin in the modulation of proximal tubule (PT) sodium reabsorption has not been considered. In the present work, we have shown that a physiologic concentration of albumin increases the expression of the α1 subunit of (Na(+) + K(+))-ATPase in LLC-PK1 cells leading to an increase in enzyme activity. This process involves the sequential activation of PI3K/protein kinase B and protein kinase C pathways promoting inhibition of protein kinase A. This integrative network is inhibited when albumin concentration is increased, similar to renal disease, leading to a decrease in the α1 subunit of (Na(+) + K(+))-ATPase expression. Together, the results indicate that variation in albumin concentration in PT cells has an important effect on PT sodium reabsorption and, consequently, on renal sodium excretion.

N-acetil-β-D-glicosaminidase como biomarcador precoce de disfunção renal para a exposição ocupacional ao chumbo inorgânico / N-acetyl-β-D-glucosaminidase as an early biomarker of renal dysfunction due to occupational exposure to inorganic lead

OBJETIVO: Este estudo teve como objetivo averiguar a atividade enzimática da N-acetil-β-D-glicosaminidase (NAG) como possível biomarcador precoce de disfunção renal para a exposição ocupacional ao chumbo inorgânico. MATERIAIS E MÉTODOS: Foi selecionado um grupo de 30 pessoas do sexo masculino expostas ao chumbo inorgânico em uma fábrica de baterias localizada no estado do Paraná. Fizeram parte do grupo os funcionários que mostraram valores de chumbo sanguíneo inferiores a 40 mg/dl. O grupo controle foi representado por 15 adultos saudáveis com similaridade em relação à idade e ao gênero do grupo exposto. Foram determinados os níveis de plumbemia, do ácido d-aminolevulínico urinário e a atividade da NAG urinária. RESULTADOS E DISCUSSÃO: Foi evidenciado que a atividade urinária da NAG foi significativamente maior (p < 0,05; teste U de Mann-Whitney) no grupo exposto ao chumbo inorgânico quando comparado ao grupo controle, e houve uma correlação negativa com significância (p < 0,05; correlação de Spearman Rank Order) entre o indicador biológico de exposição plúmbica e a atividade urinária da NAG. CONCLUSÃO: Os resultados demonstraram que o aumento da atividade urinária da NAG pode ser utilizado como um biomarcador precoce da exposição ao chumbo inorgânico.

OBJECTIVE: This study aimed to verify the enzymatic activity of N-acetyl-β-D-glucosaminidase (NAG) as a possible early biomarker of renal dysfunction due to occupational exposure to inorganic lead. MATERIALS AND METHODS: We selected a group of 30 males that had been exposed to inorganic lead in a battery factory in the state of Paraná. This group comprised those employees whose blood lead levels were below 40 mg/dl. The control group consisted of 15 healthy adults of similar age and gender compared with the exposed group. Blood lead concentrations, d-aminolevulinic acid levels and urinary NAG activity were measured. RESULTS AND DISCUSSION: It was shown that urinary NAG activity was significantly higher (p < 0.05, U test of Mann-Whitney) in the exposed group in comparison to the control group, and there was a significant negative correlation (p < 0.05, Spearman Rank Order correlation) between the biological indicator of lead exposure and urinary NAG activity. CONCLUSION: The results showed that the increase of urinary NAG activity may be used as an early biomarker of the exposure to inorganic lead.

Hsp70/nitric oxide relationship in apoptotic modulation during obstructive nephropathy.

The functional integrity of the kidney depends on normal development as well as on physiological cell turnover. Apoptosis induction is essential for these mechanisms. Multiple mechanisms are unleashed during obstructive nephropathy, one of the most complex being programmed cell death that leads to renal tubular atrophy and tubular loss. This review will focus on the interaction of nitric oxide and Hsp70 and on the regulation of renal antiapoptotic and protective oxidative stress responses.

Selective iNOS inhibition reduces renal damage induced by cisplatin.

Cisplatin is a chemotherapeutic agent used in the treatment of several cancer tumors; however, nephrotoxicity has restricted its use. Reactive oxygen species and peroxynitrite, which is formed by the reaction between superoxide anion and nitric oxide (NO*), are implicated in cisplatin-induced nephrotoxicity. In contrast, both toxic and beneficial effects of NO* have been suggested in cisplatin-induced nephrotoxicity. Therefore, nowadays the role of NO* in this experimental model remains controversial. The aim of the present work was to elucidate the role of NO* in cisplatin-induced renal damage using N-[3-(aminomethyl)benzyl]acetamidine (1400W), a selective and irreversible inhibitor of iNOS. The mRNA levels of iNOS were increased in cisplatin-treated rats. The administration of 1400W reduced the cisplatin induced histological damage, renal dysfunction (increase in proteinuria and kidney injury molecule expression and decrease in creatinine clearance), tubulointerstitial infiltration, oxidative stress (increase in renal malondialdehyde and inmmunostaining for 4-hydroxy-2-nonenal) and nitrosative stress (immunostaining for 3-nitrotyrosine). In addition, the administration of 1400W was unable to modify systolic blood pressure in control rats. Our data demonstrate that selective iNOS inhibition reduces the cisplatin-induced nephrotoxicity and nitrosative stress which strongly suggest that in this experimental model (1) the NO* production is toxic and (2) iNOS is the main source of NO*.

A role for HO-1 in renal function impairment in animals subjected to ischemic and reperfusion injury and treated with immunosuppressive drugs.

INTRODUCTION: Ischemia/reperfusion injury (IRI) represents the single major antigen-independent factor implicated in pathogenesis of chronic graft dysfunction. Tacrolimus is a calcineurin inhibitor, which has been suggested to be helpful in cyclosporine-related chronic toxicity. Rapamycin has antiproliferative properties that may impair renal regeneration after IRI. Therefore, immunosuppressive drugs might impair renal graft outcome in those organs suffering IRI. MATERIAL AND METHODS: C57B1/6 male mice subjected to 45 minutes of renal pedicle ligation were reperfused for 24 hours. Mice were treated with rapamycin, cyclosporine, or tacrolimus. Blood and renal tissue samples were collected at 24 hours after IRI. Urea levels were measured. Heme Oxygenase 1 (HO-1) gene transcript was amplified by a real-time polymerase chain reaction technique. RESULTS: Animals treated with cyclosporine and subjected to IRI showed impaired renal function that peaked at 24 hours. Additional pretreatment with rapamycin produced even more impairment of renal function, when compared with controls. However, tacrolimus pretreatment was associated with a better renal outcome. HO-1 expression was upregulated after IRI by 2.6 arbitrary units at 24 hours. Rapamycin showed worse impairment of renal function. CONCLUSION: Tacrolimus was not associated with worsening renal function when compared with animals just subjected to IRI. Upregulation of HO-1 may be an attractive approach to limit graft injury.

Evaluation of renal enzymuria and cellular excretion as an marker of acute nephrotoxicity due to an overdose of paracetamol in Wistar rats.

INTRODUCTION: The present study was conducted to determine whether the urinary levels of excreted enzymes, gamma-glutamyltransferase (GGT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), aspartate (AST) and alanine aminotransferases (ALT), can efficiently indicate, within 24 h, an acute nephrotoxicity due to an overdose of paracetamol (PAR). METHODS: A baseline urine was collected from the experimental group. Thereafter, blood collected from the orbital sinus (1.0 ml) and paracetamol (650 mg/kg of body weight) was administered by gavage. After the drug administration, animals were returned to the metabolic cages and then urine was collected in the next 22 h. Blood and urine collection was performed at time 0+24 h (T(24)), as well as at times 48 and 72 h (T(48) and T(72)). After the last urine and blood collection, the rats were killed and the kidneys removed and prepared for histological examination. Plasma creatinine and urinary levels of creatinine (to determinate glomerular filtration rate-GFR), GGT, ALP, LDH, ALT and AST were measured. Kidney tissues were stained with hematoxylin and eosin stain for histological assessment. RESULTS: Urinary levels of GGT, ALP and LDH enzymes were significantly higher (P<0.05) at T(24) when compared to the levels at T(0) and returned to basal levels at T(48) and T(72). The number of urinary epithelial cells at T(24) was significantly higher when compared to the control time (T(0)) (P<0.001). The GFR was significantly reduced 24, 48 and 72 h after the drug administration. CONCLUSION: The number of urinary epithelial cells and urinary enzymes levels are a simple and low cost procedure that is available and can help in the detection of renal acute lesions.

Losartan modulation on NOS isoforms and COX-2 expression in early renal fibrogenesis in unilateral obstruction.

BACKGROUND: Angiotensin II plays a central role in the initiation of renal fibrogenesis at a very early stage leading to a rapid progression in unilateral ureteral obstruction (UUO). We examined the effect of an angiotensin II receptor inhibitor (AT(1)) losartan, independent from its effects on blood pressure, on nitric oxide synthase (NOS) isoforms and cyclooxygenase-2 (COX-2) expression and the significance of this interaction on interstitial fibrosis in UUO. METHODS: Rats underwent UUO for 24 hours or control sham operation after been treated with losartan in the drinking water at 10 mg/kg/day for 15 days. AT(1) receptor binding and distribution was determined by in situ autoradiographic study. Renal fibrosis was evaluated through the relative volume of the tubulointerstitium (Vv) measured by an image analyzer, and transforming growth factor-beta (TGF-beta) at mRNA levels. NOS activity, expression of NOS isoforms by reverse transcription-polymerase chain reaction (RT-PCR) assay and COX-2 protein expression, were determined. RESULTS: After administration of a nonhypotensive dose of losartan prevention of renal fibrogenesis was demonstrated in obstructed kidneys by means of Vv values and TGF-beta mRNA expression near controls. Decreased AT(1) receptor binding density was observed in cortex and inner stripe of the outer medulla of nontreated obstructed kidney compared to control, whereas no differences were observed in ipsilateral UUO related to obstructed kidney-treated group. The increased inducible NOS (iNOS) activity and expression of obstructed kidney medulla, increased neuronal NOS (nNOS), and endothelial NOS (eNOS) isoforms expression and COX-2 protein expression in obstructed kidney cortex showed down-regulation of iNOS, nNOS, and COX-2 with persistent levels of eNOS after losartan administration. CONCLUSION: These results allowed us to infer an interstitial fibrogenesis prevention independent action of losartan, involving NOS isoforms and COX-2, in unilateral obstructive nephropathy.

Local induction of angiotensin-converting enzyme in the kidney as a mechanism of progressive renal diseases.

Angiotensin Converting Enzyme (ACE) or Kininase II has a pivotal role determining the local activity of the renin angiotensin and kallikrein kinin systems. Angiotensin II (Ang II), a main hormone of the renin system, has a well established participation as a renal injury agent in models of renal disease with tubulointerstitial fibrosis. Although, since its discovery, ACE has been known to convert Ang I to Ang II, and to inactivate bradykinin (BK), only recently has been emerged evidence for a role of BK with renal protective and antifibrotic effects opposing Ang II. Pertinent to the tubulointerstitial injury, where infiltration and proliferation of macrophages and fibroblast occur, ACE also regulates the levels of the natural hemoregulatory peptide, N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP). Owing the importance of tissue ACE, its distribution was studied in several models of renal injury. The results showed increased ACE in proximal tubules and ACE induction in the cell infiltrated tubulointerstitium (macrophages and myofibroblasts) of injured kidneys from hypokalemic, Goldblatt hypertensive, Ang II and phenylefrine infused rats, and in both human diabetic and membranous nephropathies. ACE, in addition to Ang II generation, may play a pathogenic role through the hydrolysis of BK and Ac-SDKP. Thus, local increase in ACE can be a novel mechanism involved in tubulointerstitial renal injury, providing, from an anatomical ground, a pathological basis for the putative deleterious effect of ACE in the diseased kidneys, and the beneficial effect of ACE inhibition.

HO-1 induction attenuates renal damage and oxidative stress induced by K2Cr2O7.

Heme oxygenase (HO) is the rate-limiting enzyme in the degradation of heme; its inducible isozyme HO-1 protects against some types of acute tissue injury. The expression and functional role of HO-1 in rats with renal injury induced by potassium dichromate (K(2)Cr(2)O(7)) was investigated in this work. Rats were studied 24 h after a single injection of K(2)Cr(2)O(7). To address the possible protective effect of HO-1 in this experimental model, this enzyme was induced by an injection of stannous chloride (SnCl(2)) 12 h before K(2)Cr(2)O(7) administration. The functional role of HO-1 in K(2)Cr(2)O(7) + SnCl(2)-treated animals was tested by inhibiting HO activity with an injection of zinc (II) protoporphyrin IX (ZnPP) 18 h before K(2)Cr(2)O(7). In K(2)Cr(2)O(7)-treated rats: (i) renal HO-1 content, measured by Western blot, increased 2.6-fold; and, (ii) renal nitrotyrosine and protein carbonyl content, markers of oxidative stress, increased 3.5- and 1.36-fold, respectively. Renal damage and oxidative stress were ameliorated and HO-1 content was increased in the K(2)Cr(2)O(7) + SnCl(2) group. The attenuation of renal injury and oxidative stress was lost by the inhibition of HO activity in K(2)Cr(2)O(7) + SnCl(2) + ZnPP-treated animals. Our data suggest that HO-1 overexpression induced by SnCl(2) is responsible for the attenuation of renal damage and oxidative stress induced by K(2)Cr(2)O(7).

[Nephropathy in a case of Fabry's disease]. / Nefropatía en un caso de enfermedad de Fabry.

The present communication describes a 22 year-old male with clinical, biochemical and histopathological signs of Fabry's disease (FD). This is the second case of FD reported in Mexico. The main clinical manifestations of this patient were during puberty: intermittent weakness, acroparesthesias and hypohidrosis. At age 21 he developed heavy proteinuria (7-12 g/day) systemic hypertension and moderate renal failure. The kidney biopsy showed the typical alterations described in FD. On light microscopy, the renal pathology showed numerous vacuolated epithelial cells in the glomerular wall, giving them a "foamy" appearance; vacuolization was due to the presence of lipid material within these cells and in the interstitium. In electron microscopy, dense, irregularly shaped osmiophilic, laminated bodies with myelinlike configuration, were seen within the glomerular epithelial cells and in the urinary spaces. The low alfa-galactosidase activity in serum (0.18 nmol/h/mL normal values: 12.8) confirmed the diagnosis. Our findings in this case indicate that patients with FD may start with renal symptoms alone, which were full blown nephrotic syndrome, hypertension and moderate renal failure.

Serum angiotensin converting enzyme activity and plasma renin activity in experimental models of rats.

1. Serum angiotensin converting enzyme activity (ACEA) and plasma renin activity (PRA) were determined in rats under different experimental conditions such as: nephrotic syndrome (NS), bilateral nephrectomy (BN), renovascular hypertension (RH), dehydration (DEH), anaesthesia (AN), low sodium diet (LSD) and high sodium diet (HSD), and injection with propranolol (PRO) and isoprenaline (ISO). 2. PRA increased in LSD, AN, NS, RH, DEH and IPT groups, and decreased in HSD, BN, and PRO groups. Serum ACEA did not change in RH, HSD, IPT, DEH, AN, and PRO groups, increased in NS group, and decreased in LSD and BN groups. 3. Serum ACEA changed in the opposite direction to PRA only in the LSD group. This finding suggests that ACE may limit the full expression of the renin-angiotensin system in the LSD group, but not in the other groups.

Pseudo-Zellweger syndrome: deficiencies in several peroxisomal oxidative activities.

We describe an infant girl with a clinical, chemical, and pathologic syndrome remarkably similar to Zellweger cerebrohepatorenal syndrome but whose liver parenchymal cells contained abundant peroxisomes. Peroxisomal L-alpha hydroxy acid oxidase, catalase, and the plasmalogen synthesizing enzyme dihydroxy acetone phosphate-acyl transferase activities were normal; other peroxisomal enzymatic activities, including fatty acyl-CoA oxidase and D-amino acid oxidase, were reduced by 80% to 85%. Oxidation of bile acids and pipecolic acid was also deficient. Autopsy revealed the presence of neuronal heterotopia, renal cortical cysts, adrenal atrophy, and accumulation of very long chain fatty acids. The clinical and pathologic features of this case of "pseudo-Zellweger syndrome" reflect a deficiency in multiple peroxisomal activities rather than a defect in peroxisomal biogenesis. The deficient enzymatic activities require flavin adenine dinucleotide, and the underlying defect may be in the utilization of this cofactor.