• Journal of Nutrition and Health
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• v.29 no.10
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• pp.1059-1071
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• 1996

This study was performed to investigate the effect of dietary protein level on renal senescence. Male rats of 337.8$\pm$5.7g body weight were underlateral nephrectomy or shamoperation. The rats were divided into high protein(40% casein), normal protein(15% casein) and low protein(8% casein)diets and fed experimental diets ad libitum for 24 weeks. The results are summarized as follows. There was a hypertophy of the remnant kidney of uninephrectomized rats of 40% or 15% protein group, coming up to the comparable weights of both kidneys of sham-operated rats. However, the hypertrophic effect was not seen in uninephrectomized rats of 8% protein group. Serum albumin was lower in uninephrectomized rats. With increasing dietary protein level blood urea nitrogen was increased, whereas, urinary urea nitrogen excretion was decreased. Urinary solute excretion was higher in uninephrectomized group than in sham-operated group. However, effect of dietary protein level on urinary solute excretion varied dpending on th solutes tested. GFR and urinary protein excretion, throughout experiment, increased with feeding period and with dietary protein level. Proteinuria was most severe in uninephrectomized rats fed 40% casein diet. Maximum urine concentration ability measured after dehydration was not different among the experimental groups. Light microscopic examination showed focal segmental glomerulosclerosis and mild increas of glomerular mesangial matrix in uninephrectomized rats fed 40% and 15% protein diet, however, which was not observed in uninephrectomized rats fed 8% protein diet and in sham-operated rats fed 40% diet. Immunofluorescence studies revealed segmental deposits of albumin in the mesangium and capillary loops in high protein and uninephrectomized groups. Minimal granular deposition of IgG was noted in the mesangium of all experimental groups. In conclusion, high protein intake accelerated deterioration of renal function and it was correlated with morphological change. Low protein intake was effective in preventing these changes.

• Childhood Kidney Diseases
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• v.4 no.1
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• pp.6-10
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• 2000

Purpose: To evaluate whether the urinary creatinine concentration is a reliable reference value to standardize urinary solute excretion in a spot urine sample during the first week of life. Methods: Spontaneously voided urine specimens were obtained in 49 healthy full term neonates, and in 33 healthy older children with the median ages of $5.7{\pm}4.3$ years, two urine samples were available with an interval of 2 to 3 days. Urine creatinine concentration was determined by the Jaffe test(CoBAS, Integra, Roche, Swiss). Uurine osmolality was determined by the freezing point depression test(Multi-osmette, Precision, USA). Results: Mean urinary creatinine and osmolality values of the first urine samples were not significantly different with the second urine samples in each group. Mean urinary creatinine and osmolality values in neonates were significantly different from the older children of the each urine sample(P<0.01). In neonates, the mean of the urinary oreatinine/osmolality ratios was higher than that of the older children(P<0.01). The urinary creatinine and the creatinine/osmolality values of the first urine samples were closely correlated with those of the second samples in both two groups(P<0.001). Conclusion: The urinary creatinine concentration during the first day of life is relatively stable, even when corrected for urinary osmolality The urinary creatinine and the urinary creatinine/osmolality ratio, therefore, can be used to standardize the urinary excretion of solutes in the neonate.

• Environmental Mutagens and Carcinogens
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• v.25 no.2
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• pp.60-65
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• 2005

The human solute carrier, SLC41Al, is a $Mg^{2}+$ transporter that is regulated by extracellular magnesium. Although intracellular magnesium plays a fundamental role in cellular metabolism, little is known about how $Mg^{2}+$ is taken up and controlled by cells. Magnesium plays a fundamental role in cellular metabolism so that its control within the body is critical. Magnesium homeostasis is principally a balance between intestinal absorption of dietary magnesium and renal excretion of urinary magnesium. The kidney, mainly the distal convoluted tubule, controls magnesium reabsorption. Although renal reabsorption is under the influence of many hormones, selective regulation of magnesium transport is due to intrinsic control involving transcriptional processes and synthesis of transport proteins. Using microarray analysis, identification of the genetic elements involved with this transcriptional control has been begun. SLC41A1(GenBank Accession No. AJ514402), comprises 10 putative transmembrane domains, two of which are highly homologous to the integral membrane part of the prokaryote transports $Mg^{2}+$ and other divalent cations $Sr^2+,\;Zn^2+,\;Cu^2+,\;Fe^2+,\;Co^2+,\;Ba^2+,\;and\;Cd^2+,\;but\;not\;Ca^2+,\;Mn^2+,\;and\;Ni^2+.$ Transport of $Mg^{2}+$ by SLC41Al is rheogenic, voltage dependent, and not coupled to Na or Cl. Expressed SLC41Al transports a range of other divalent cations: $Mg^{2+},\;Sr^{2+},\;Zn^{2+},\;Cu^{2+},\;Fe^{2+},\;Co^{2+},\;Ba^{2+},\;and\;Cd^{2+}$. The divalent cations $Ca^{2+},\;Mn^{2+},\;and\;Ni^{2+}$and the trivalent ion $Gd^{3+}$ did not induce currents nor did they inhibit $Mg^{2+}$ transport. The nonselective cation $La^{3+}$ abolishes $Mg^{2+}$ uptake. Computer analysis of the SLC41Al protein structure reveals that it belongs to MgtE protein family & suggested that the human solute carrier, SLC41Al, might be a eukaryotic $Mg^{2+}$ transporter closely related $(60-70\%)$ protein encoded by SLC41A2 is a $Mg^{2}+$ transporter that might be involved in magnesium homeostasis in epithelial cells also transports a range of other divalent cations: $Ba^2,\;Ni^2,\;CO^2,\;Fe^2,\;or\;Mn^2,\;but\;not\;Ca^2,\;Zn^2,\;or\;Cu^{2+}$ that may have related functional properties.

• Childhood Kidney Diseases
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• v.14 no.2
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• pp.111-119
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• 2010

The maintenance of the osmolality of body fluids within a very narrow physiologic range is possible by water balance mechanisms that control the intake and excretion of water. Main factors of this process are the thirst and antidiuretic hormon arginine vasopressin (AVP), secretion regulated by osmoreceptors in the hypothalamus. Body water is the primary determinant of the osmolality of the extracellular fluid (ECF), disorders of body water homeostasis can be divided into hypo-osmolar disorders, in which there is an excess of body water relative to body solute, and hyperosmolar disorders, in which there is a deficiency of body water relative to body solute. The sodium is the predominant cation in ECF and the volume of ECF is directly proportional to the content of sodium in the body. Disorders of sodium balance, therefore, may be viewed as disorders of ECF volume. This reviews addresses the regulatory mechanisms underlying water and sodium metabolism, the two major determinants of body fluid homeostasis for a good understanding of the pathophysiology and proper management of disorders with disruption of water and sodium balance.

• Herbal Formula Science
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• v.10 no.1
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• pp.113-129
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• 2002

The present study designed to investigate whether hwangryunhaedok-tang show an anti-hypertensive effect and elucidate its possible mechanism in spontaneously hypertensive rats. The systolic blood pressures (SBP) were significantly decreased as an oral administration of hwangryunhaedok-tang compared with their control group. The urine volume was significantly increased by administration of hwangryunhaedok-tang but urinary sodium (UNaV), potassium (UKV), chloride excretion (UCIV) were not remarkably affected. The urinary creatinine excretion rate (UcrV) was significantly increased in rats administered with hwangryunhaedok-tang in association with increase of creatinine clearance (Ccr). The urine osmolality (Uosmol) was significantly decreased in SHR administered with hwangryunhaedok-tang without being changed in solute-free water reabsorption ( TcH20). The expressions of Aquaporin 2 (AQP-2). 3 and ${\alpha}\;1$, ${\beta}\;1$ subunits of Na.K-ATPase were determined by Western blot analysis to assess the role of these proteins in association with changes of renal functions in SHR administered with hwangryunhaedok-tang. The expression of AQP-2 and 3 protein was significantly down-regulated in the kidney of SHR administered with hwangryunhaedok-tang compared with those in control rats without being altered expression of ${\alpha}\;1$, ${\beta}\;1$ subunits of Na,K-ATPase. In the in vitro assay, Angiotensin converting enzyme (ACE) was inhibited by hwangryunhaedok-tang in a dose-dependent manner. Berberine and/or palmatine, which are well known as a main components of hwangryunhaedok-tang, also have an ACE inhibitory effects in a dose-dependent manner. Taken together, these results suggest that hwangryunhaedok-tang lowered blood pressure through the increase of diuresis caused by down-regulation of water channels and the inhibition of Angiotensin converting enzyme.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.2
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• pp.423-427
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• 2003

The present study was aimed to investigate whether ethanol-extract of Allium wageki has an ameliorative effect on the renal function in high fructose-diet induced hypertensive rats .. The urine osmolality (Uosmol) was decreased in rats with high fructose-diet (60%) during the whole experiment period without change of the urine volume (UV). The urinary excretion of sodium (UNaV) and chloride (UCIV) were decrease significantly in rats with fructose-induced hypertensive rats, whereas urinary excretion of potassium (UKV) was Increased. The creatinine clearance (Ccr) and solute-free water reabsorption were also decreased by treatment of fructose-rich diet. Among these renal functional parameters, Ccr was partially restored by the administration of ethanol-extract of Allium wageki. The Uosmol was also partially restored by the administration ethanol-extract of Allium wageki at the end of the experimental period. Taken together, ethanol-extract of Allium wageki has the ameliorative effect on glomerular filtration rate in rats with high fructose-diet induced hypertension.

• Journal of the East Asian Society of Dietary Life
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• v.15 no.2
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• pp.165-170
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• 2005

The present study was aimed to investigate whether ethanol-extract of Nelumbo nucifera has an ameliorative effect on the renal function in high fructose-diet induced hypertensive rats. The urine osmolality (Uosmel) was decreased in rats with high fructose-diet ($60\%$) during the whole experiment period without change of the urine volume (UV). The urinary excretion of sodium and chloride were decrease significantly in rats with fructose induced hypertensive rats, wheras urinary excretion of potassium was increased. The creatinine clearance (CCr) and solute-free water reabsorption were also decreased by treatment of fructose rich diet. Among these renal functional parameters, CCr was partially restored by the administration of ethanol-extract of Nelumbo nucifera. The Uosmol was also partially restored by the administration ethanol-extract of Nelumbo nucifera at the end of the experimental period. Taken together, ethanol-extract of Nelumbo nucifera has the ameliorative effect on glomerular filtration rate in rats with high fructose-diet induced hypertension.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.5
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• pp.1201-1209
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• 2007

The present study was designed to examine whether water extract of Acanthopanacis cortex(AC) has an effect on renal functional parameters in association with the expression of aquaporin 2 (AQP-2) and heme oxygenase-1 (HO-1) in the ischemia/reperfusion induced acute renal failure (ARF) rats. Polyuria caused by down-regulation of renal AQP 2 in the ischemia-induced ARF rats was markedly restored by administration of AC (200 mg/kg, p.o.) with restoring expression of AQP 2 in the kidney. Administration of AC lowered the renal expression of HO-1, which was upregulated in rats with ischemia/reperfusion-induced ARF. The renal functional parameters including creatinine clearance, urinary sodium excretion, urinary osmolality, and solute-free reabsorption were also markedly restored in ischemia-ARF rats by administration of AC. Histological study also showed that renal damages in the ARF rats were abrogated by administration of AC. Taken together, the present data indicate that AC ameliorates renal defects in rats with ischemia/reperfusion-induced ARF.

• Childhood Kidney Diseases
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• v.20 no.1
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• pp.11-17
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• 2016

Appropriate control of diet and water intake is important for maintaining normal blood pressure, fluid and electrolyte homeostasis in the body. It is relatively understood that the amount of sodium and potassium intake directly affects blood pressure and regulates ion transporters; Na and K channel functions in the kidney. However, little is known about whether diet and water intake regulates Aquaporin (AQP) function. AQPs, a family of aquaporin proteins with different types being expressed in different tissues, are important for water absorption by the cell. Water reabsorption is a passive process driven by osmotic gradient and water permeability is critical for this process. In most of the nephron, however, water reabsorption is unregulated and coupled to solute reabsorption, such as AQP1 mediated water absorption in the proximal tubule. AQP2 is the only water channel founded so far that can be regulated by hormones in the kidney. AQP2 expressed in the apical membrane of the principal cells in the collecting tubule can be regulated by vasopressin (antidiuretic hormone) controlling the final volume of urine excretion. When vasopressin binds to its receptor on the collecting duct cells, it stimulates the translocation of AQP2 to the membrane, leading to increased water absorption via this AQP2 water channel. However, some studies also indicated that the AQP2 is also been regulated by vasopressin independent mechanism. This review is focused on the regulation of AQP2 by diet and the amount of water intake on salt and water homeostasis.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.1
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• pp.84-92
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• 2004

The present study examined the effects of Taekunyukmijiwhang-tang (TV) on blood pressure and renal function in nitric oxide (NO)-dependent hypertensive rats. A phamacological inhibition of nitric oxide synthase (NOS) for 4-6 weeks produces renal vasoconstriction, renal dysfunction, and progressive severe hypertension. Treatment of rats with NG-Nitro-L-arginie methylester (L-NAME) (100 mg/L, 6 weeks), which is a nonspecific NOS inhibitor, cause a sustained increase in systolic blood pressure (SBP), along with the decrease in expression of ecNOS in the kidney and thoracic aorta. The expression of Na, K-ATPase α1 subunit in the kidney was also reduced in the L-NAME induced hypertensive rats group. The renal functional parameters including urine osmolality (Uosm), creatinine clearance (Ccr), which is an index of glomerular filtration (GFR) were decreased in rat with L-NAME induced hypertension. while solute-free water reabsoption (TcH₂O) was unchanged in all experimental group. However, the group combined treated with TV and L-NAME did not develop hypertension and expression of ecNOS in the aorta was restored. The expression of Na/sup +/, K/sup +/-ATpase α1 subunit in the kidney was markedly restored in L-NAME-induced hypertension rats by administration of TV along with the restoration of urinary volume (UV) and sodium excretion (UNaV), whlie Na/sup +/, K/sup +/-ATPase /β1 subunit was not altered. These results suggest that TV attenuates an increase in SSP in the L-NAME induced hypertension and restores partially renal function, which seems to be caused by up-regulation of expression of Na/sup +/, K/sup +/-ATPase α1 subunit in the kidney and ecNOS in thoracic aorta.