• The Korean Journal of Pharmacology
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• v.32 no.2
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• pp.259-267
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• 1996

In an attempt to dofine the early biochemical determinants that participate in the pathogenesis of glycerol-induced nephrotoxicity, especially focusing on oxygen free radicals and $N-acetyl-{\beta}-D-glucosaminidase$ (NAG) activity, we studied 24-hours urine outflow, 24-hours urinary protein excretion and urinary NAG activity after the injection of glycerol and also we studied malondialdehyde(MDA) level and superoxide dismutase(SOD) activity in the kidney of rats at 24hr after the injection of glycerol. Sprague-Dawley albino rats weighing 240 to 260 gm were injected intramuscularly with a 50% solution of glycerol(2ml/kg, 4ml/kg and 8ml/kg). The group treated with glycerol showed significantly lower urine outflow level and urinary protein excretion level and higher urinary NAG activity after the injection as compared to those of control group. Also the group treated with glycerol showed significantly higher MDA level and lower SOD activity at 24hr after the injection as compared to those of control group. These results suggest that the excessive oxygen free radicals resulting from the depression of SOD activity is an important determinant in the pathogenesis of glycerol-induced nephrotoxicity and higher urinary NAG activity is an index of renal tubular cell damage in the glycerol-induced nephrotoxicity.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.3 no.2
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• pp.166-176
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• 1993

In order to investingate the renal dysfunction in workers exposed to aromatic organic solvents, 105 male exposed workers and 109 controls were participated in this study. This study was conducted to examine the correlation among the concentration of aromatic organic solvents in air, worker's urinary NAG activity and urinary hippuric acid. The results were as follows : 1. The exposure level of aromatic organic solvent mixture caculated by the equation proposed by ACGIH was ranged from 0.27 to 0.54 and toluene concentration was ranged from 18.3ppm to 48.3ppm. 2. NAG activity in the urine of control and exposed group were $36.1{\pm}14.2nmolMU/mg$ creatinine and $52.4{\pm}26.1nmolMU/mg$ creatinine, respectively. Hippuric acid concentration in the urine of control and exposed group were $191.1{\pm}194.2mg/g$ creatinine and $789.3{\pm}784.1mg/g$ creatinine, respectively. 3. Correlation coefficent between the exposure level of aromatic organic solvent mixture was significantly related to urinary NAG activity(r=0.542) and urinary hippuric acid(r=0.752). 4. Correlation coefficient between NAG activity and hippuric acid concentration was 0.357. This study suggested that urinary NAG activity was a good renal function index for aromatic organic solvents exposure and urinary hippuric acid was an index for the biological monitoring of toluene exposure.

• Journal of Preventive Medicine and Public Health
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• v.26 no.1 s.41
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• pp.49-64
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• 1993

To provide the basic data for assessment of renal dysfunction related to silicosis, urinary N-acetyl-$\beta$-D-giucobarninidase(NAG) activity known as a sensitive markers for early renal damage were measured in 58 silicosis patients, and control subjects of 40 pulmonary tuberculosis Patients and 51 official workers. The results were summarized as fellows. 1. The values of blood urea nitrogen and serum creatinine in all subjects were within reference limits. But the mean value of urinary NAG activity($7.25{\pm}7.31U/g\;creatinine$) was beyond reference value and more sensitive test than others. 2. The mean value of urinary NAG activity in silicosis group was $11.98{\pm}9.05U/g\;creatinine$ and significantly higher than in tuberculosis and healthy group(p<0.01), but the mean values of NAG activity in tuberculosis and healthy group were not different(p>0.05). 3. The value of NAG activity in tuberculosis had a tendency to be increased according to severity of disease, but that was not significant(p>0.05). The value of NAG activity was increased significantly by use of nephrotoxic antituberculosis drugs(p<0.05). 4. The value of NAG activity in silicosis had a tendecy to be increased according to the size of nodule, use of nephrotoxic antituberculosis drugs and shortness of onset duration, but the increase was not significant(p>0.05). 5. After excluding the users of nephrotoxic antituberculosis drugs, the mean values of NAG activity in healthy control and in tuberculosis control were same as 3.63 U/g creatinine and 3.60 U/g creatinine, respectively. But the mean value of NAG activity in silicosis group was remarkably increased as 10.90 U/g creatinine(p<0.01). As above results, even though there are no abnormal finding in screening renal function test, silicosis can be related with renal dysfunction. And it will be very useful to apply urinary NAG activity in health management of workers exposed to dust.

• Journal of Preventive Medicine and Public Health
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• v.27 no.3 s.47
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• pp.547-556
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• 1994

In order to identify the necessary information of biochemical Indices for renal effect of lead for the early detection in medical surveillance of lead worker, the reference values of urinary N-acetyl-$\beta$-D-glucosaminidase (NAG) activities were studied with 205 office workers in one industrial complex area who were not exposed to lead occupationally. While study variables selected for lead exposure were blood lead (PbB), blood zinc protoporphyrin(ZPP) and $\delta$-aminolevulinic acid (DALA) in urine, those for renal effect were urinary N-acetyl-$\beta$-D-glucosaminidase (NAG), blood urea nitrogen (BUN), serum creatinine(Cr), serum uric acid (Ua), and urinary total protein(U-TP). The results obtained were as follows: 1. The mean values of blood lead, ZPP and DALA in all subjects were $14.39{\pm}4.02{\mu}g/dl,\;21.61{\pm}8.00{\mu}g/dl,\;and\;2.73{\pm}0.90mg/l$ respectively. 2. The mean value of urinary NAG activities in all subjects was $3.51{\pm}2.01U/l$. The mean value of urinary NAG activities, which calculated from NAG activities divided by urinary creatinine concentration (CNAG), was $5.42{\pm}5.53U/g$ creatinine and log-arithmic normal distributed. 3. The reference value of urinary NAG activity was 12.06 U/g creatinine(95% CU=10.57-14.76 U/g creatinine). 4. Logarithmic CNAG(r=0.781 p<0.0l), U-TP(r=0.670 p<0.01) and ZPP(r=0.172 p<0.05) showed statistically significant correlation with CNAG.

• Journal of Preventive Medicine and Public Health
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• v.31 no.3 s.62
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• pp.424-439
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• 1998

Urinary cadmium is used as a sensitive indicator for internal Cd dose, and increased excretion of $N-acetyl-\beta-D-glucosaminidase(NAG)$, $\beta_2-microglobulin(MG)$ and total protein are useful indices for renal dysfunction by chronic exposure to Cd. The target group was 184 inhabitant(82 men and 102 women) in an abandoned mine area known as exposure to low level Cd. The control group was took 160 individuals(64 men and 96 women) in Cd not-exposed area. Urinary Cd concentration was significantly higher in the target group than the control. The geometric mean of urinary Cd for male was $2.56{\mu}g/\ell,\;2.80{\mu}g/g$ creatinine and $2.50{\mu}g/S.G.$ in the target group and $1.19{\mu}g/\ell,\;1.36{\mu}g/g$ creatinine and $1.17{\mu}g/S.G.$ in the control. For female $2.69{\mu}g/\ell,\;3.94{\mu}g/g$ creatinine and $2.63{\mu}g/S.G.$ in the target group and $1.27{\mu}g/\ell,\;1.97{\mu}g/g$ creatinine and $1.25{\mu}g/S.G.$ in the control, respectively. In addition, urinary Cd of the target group had affected by the period of residence and dietary habit for the rice and the vegetables from the target area. These findings suggest the chronic exposure to Cd of the target population. Mean excretion of urinary NAG, $\beta_2-MG$ and total protein were not significant between two groups. In the target group, urinary NAG activity and total protein were significantly correlated with urinary Cd, but $\beta_2-MG$ was not related. Urinary excretion of NAG, $\beta_2-MG$ and total protein were significantly increased in $10\leqq$ than in <2 of urinary Cd level. In $2\sim10$ group of urinary Cd level, the excretion of NAG significantly increased while not showed for $\beta_2-MG$. In present study, urinary excretion of NAG was relatively sensitive than $\beta_2-MG$ in chronic exposure population to low level Cd.

• Biomolecules & Therapeutics
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• v.8 no.3
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• pp.241-247
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• 2000

The present study was designed to assess the protective effect of a selective thromboxane $A_2$ receptor antagonist, KT2-962 (KT2) and possible mechanisms of adriamycin(AD)-induced nephrotoxicity in rats. The male Wistar rats were given either of AD (7.5 mg/kg, i.v.) alone in the AD-group (n=5) or in KT2+AD- group (n=5) which is a combination of AD and KT2 (30 mg/kg/day, i.p.) for 10 days from 3 days before and 7 days after AD injection. The body weight, 24-hours urine volume, urine protein and urinary N-acetyl-$\beta$-D-glu-cosaminidase (NAG) activity were measured with an interval of 2 days during 1 week. BUN, serum creatinine and creatinine clearance were measured on the 7th day. KT2 has significantly suppressed AD-induced change of body weight, 24-hours urine volume, urine protein and urinary NAG activity in the KT2+AD-group. The change of BUN, serum creatinine and creatinine clearance were significantly inhibited in the B7T2+AD-group. Based on these results, it is concluded that KT2 prevents AD-induced nephrotoxicity and suggests that endogenous thromboxane A2 may play an important role in AD-induced nephrotoxicity in rats.

• Toxicological Research
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• v.12 no.1
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• pp.47-52
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• 1996

The renal toxicity of the extract of Polygalae Radix was investigated in rats. Rats were treated with 3.5 mg/Kg of the extract, i.p., for 7 days. Changes in consumatory behavior, 24 hour-urine and the activities of urinary enzymes were determined during the administration of the extract. Significant decrease in body weight and food consumption and increase in 24 hour-urine volume were observed during the administration. However, the quantity of total creatinine in urine was decreased significantly. Those indicate that subacute treatment with the extract might induce diuresis and the ditiresis might be due to the decrease in water reabsorption. In the activities of urinary enzymes, the activities of alanine aminopejotidase (AAP) and gamma-glutamyl transpeptidase (GGT) were increased 4.3 and 3.5 times and then returned to the control. The activity of N-acetyl-${\beta}$-D-glucosaminidase (NAG) was increased 7.2 times and then decreased slowly. But, it was significantly higher than that of the control evea after the last administration. The activity of factate dehydrogenase (LDH) was increased continuozlsly during the treatment. It showed 32 times higher than the control. These results suggested that the extract of Polygalae Radix had toxic effect on kidney. Furthermore, the result suggested that the subacute administration of the extract induced resistance against the toxicity of Polygalae Radix.

• Biomolecules & Therapeutics
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• v.6 no.2
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• pp.130-138
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• 1998

In this study, the effect of verapamil (VER) on cyclosporin A (CsA)-induced nephrotoxicity was investigated in uninephrectomized rats. Male Wistar rats were administered CsA (50 mg/kg/day, p.o.) or VER (0.5 mg/kg/day, i.p.) with CsA (50 mg/kg/day, p.o.) for 20 days. The urinary N-acetyl-$\beta$-D-glucosaminidase (NAG) activity along with BUN, serum creatinine, creatinine clearance (CLcr), body weight, and 24 hr-urine output were measured and histopathologic changes of kidney were evaluated by light and electron microscopy. The results obtained from this study can be summarized as follows: While NAG activity, BUN and serum creatinine was progressively increased and CLcr significantly decreased in CsA group, VER almost signifi-cantly (p<0.05) suppressed and normalized CsA-induced changes in VER+CSA group. While urine output increased until 12th days and thereafter progressively decreased in CsA group, it gradually increased in control and VER+CSA group. While body weight progressively made a gain in control and VER+CSA groups, it significantly (p<0.05) lost in CsA group. On light microscopy, the glomerular hyperemia and proximal convoluted tubular (PCT) dilatation, focal tubular cell vacuolation and necrosis were clearly evident in CsA group, but, were not seen in other groups. Ultrastructural studies revealed thickened glomerular endothelium and basal lamina of capillary, irregular shaped pedicels of podocytes, indistinct slit pores and narrowed bowman's space. The large oval vacuoles with dense debris and phagosome were distributed in apical zone and deformed microvilli and mitochondria were seen in the PCT cell of CsA group. But, glomeruli and PCT cell were relatively preserved in normal apperance in other groups. In conclusion, it is suggested that verapamil has a protective effect on cyclosporine-induced nephrotoxicity in uninephrectomized rats.

• Journal of Environmental Health Sciences
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• v.37 no.6
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• pp.450-459
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• 2011

Objectives: Biomarkers in urine are important in assessing exposures to environmental or occupational chemicals and for evaluateing renal function by exposure from these chemicals. Spot urine samples are needed to adjust the concentration of these biomarkers for variations in urine dilution. This study was conducted to evaluate the suitability of adjusting the urinary concentration of cadmium (uCd) and arsenic (uAs) by specific gravity (SG) and urine creatinine (uCr). Methods: We measured the concentrations of blood cadmium (bCd), uCd, uAs, uCr, SG and N-acetyl-${\beta}$-D-glucosaminidase (NAG) activity, which is a sensitive marker of tubular damage by low dose Cd exposure, in spot urine samples collected from 536 individuals. The value of uCd, uAs and NAG were adjusted by SG and uCr. Results: The uCr levels were affected by gender (p < 0.01) and muscle mass (p < 0.01), while SG levels were affected by gender (p < 0.05). Unadjusted uCd and uAs were correlated with SG (uCd: r = 0.365, p < 0.01; uAs: r = 0.488, p < 0.01), uCr (uCd: r = 0.399, p < 0.01; uAs: r = 0.484, p < 0.01). uCd and uAs adjusted by SG were still correlated with SG (uCd: r = 0.360, p < 0.01, uAs: r = 0.483, p < 0.01). uCd and uAs adjusted by uCr and modified uCr ($M_{Cr}$) led to a significant negative correlation with uCr (uCd: r = -0.367, p < 0.01; uAs: r = -0.319, p < 0.01) and $M_{Cr}$ (uCd: r = -0.292, p < 0.01; uAs: r = -0.206, p < 0.01). However, uCd and uAs adjusted by conventional SG ($C_{SG}$) were disappeared from these urinary dilution effects (uCd: r = -0.081; uAs: r = 0.077). Conclusions: $C_{SG}$ adjustment appears to be more appropriate for variations in cadmium and arsenic in spot urine.