Removal of excess fluid from patients with chronic renal failure is one of the major objectives of peritoneal dialysis (PD). Water movement from capillary to dialysate derives from the dialysate-to-capillary osmotic gradient across the peritoneum. To explain the mechanism of water movement driven by the osmotic gradient through the peritoneum, the notion of a water selective "ultra small pore" has been proposed. The purpose of this study was to investigate the involvement of peritoneal water channels in water movement across the peritoneum in PD. The abdominal cavity of male anesthetized rats was catheterized for administration of a series of artificial dialysates. Experimental PD was performed for 90-180 min with 25 ml of hyperosmotic dialysate generated by glucose (600 mOsm), sucrose (600 mOsm), and sodium (1800 mg/dl, 600 mOsm). Analysis of the sodium concentration and osmolality of dialysate during experimental PD showed mercurial sensitive water transport that was compatible with water channel-mediated water transport in the peritoneum. RT-PCR amplification with cDNAs constructed from peritoneal mRNA revealed the existence of both AQP1 (CHIP28) and AQP4 (MIWC) water channels in the peritoneum. PD with hyperosmotic dialysate did not affect the expression of peritoneal water channels. As a result of an in situ hybridization study to investigate the localization of the peritoneal water channels, it was found that both channels were expressed in the sub-mesothelial layer containing capillaries. The results obtained in this study suggest that peritoneal water channels might play a role in fluid removal during PD.

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Mesangial cell (MC) proliferation is the pricipal cause of glomerulonephritis and glomerulosclerosis. Previous studies have demonstrated that various cytokines and growth factors are MC mitogens.In vitro, basic fibroblast growth factor (FGF2) stimulates MC proliferation. In the present study, two series of experiments were conducted using rats with anti-Thy1.1 mesangial proliferative glomerulonephritis. The first series of experiments was designed to clarify the expression relationship between FGF2, FGF, receptor-1 (FGFRI) and α-smooth muscle actin ( a -SMA). The second series examined the effect of intravenous administration of recombinant FGF2 in this model. The first series involving in situ hybridization with FGF2 and FGFR 1 cRNA probes, showed that these mRNAs were expressed in the mesangial areas during the proliferative phase (days 4-7). Simultaneously, the α-SMA scores of glomeruli also increased. In the second series, FGF2 was administered at 6, 12 and 24 hours (early group) and at 4, 5, and 6 days (late group) after disease induction. On day 7, there were more glomerular cells positive for proliferative cell nuclear antigen (PCNA) in the late group than in the control and early groups and the α-SMA scores of the glomeruli had increased in the late group. On day 14, the number of mesangial cells mainly increased in the late group. These findings suggest that FGF2 and FGFRI showed significant correlation with the phenotypic changes of MC.

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There have been many reports on changes in renal morphology with aging. In this study, morphological comparisons were made on the influence of aging in humans and rats. Kidneys were obtained from 63 autopsies (except those from cases of tumor, severe cicatrization, and cysts 10 mm or more in diameter) performed on humans aged from 0 to 92 years, including 7 cases with a past history of hypertension; the findings were compared with those from 201 Wistar male rats aged three to 115 weeks. First, changes in renal weight and renal cortex width were investigated. Next, changes in renal morphology were examined by microscopy. Finally, after performing alcian-blue-PAS staining, the ratio of the intima/outer diameter (I/OD ratio) of the renal blood vessel was measured under a microscope with an image analyzer, and the results compared. A decrease in renal weight was ob-served in humans from about 50 years of age, but there was no decrease in weight with aging among rats. While significant thickening in the vascular intima was observed with aging in humans, there was no such thickening among rats. Furthermore, the presence of hypertension caused renal cortex width to be significantly decreased in humans (p<0.04). Findings of sclerogenous changes of the glomeruli, infiltration of chronic inflammatory cells and fibrosis in the stroma, and tubular casts were observed with aging in both humans and rats. In conclusion, arteriosclerosis apparently develops with aging in humans, suggesting that arteriosclerosis greatly influences the reduction of human renal weight.

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The process of glomerular injury in nephrotoxic serum nephritis (NTN) is dependent on proinflammatory cytokines. In the present investigation, we assessed the actions of neutralizing antibody against IL-1, 9, TNF-α, IL-6 and TGF-β1 on glomerular injury. Marked increase in IL-1 and IL-6 was detected in cultured glomeruli of NTN in mice throughout the experiments from disease induction. Protein of TNF-α and TGF-$1 also increased in NTN mice 1 day after disease induction. Treatment with either IL-l, S or TNF- a neutralizing antibody reduced proteinuria from 71 ± 11.2 m g/24 hr to 32.2±6.0 (P<0.01), 34.3±6.8 mg/24 hr (P<0.01), respectively. Although the effect of IL-6 neutralizing antibody on proteinuria was not remarkable, the decreased creatinine clearance was improved more than that of IL-1 βor TNF-α. Antibody against TGF-β 1 had no effect on proteinuria and creatinine clearance. Treatments with IL-1 β, TNF-α and IL-6 neutralizing antibodies inhibited glomerular hypercellularity in NTN mice. TGF-β1 neutralizing antibody suppressed the index of mesangial matrix expansion. IL-l, 3 and TNF-αneutralizing antibodies prevented the increase in the number of macrophages in the glomeruli. The number of PCNA positive cells and alpha;-smooth muscle actin expression in glomeruli was significantly reduced in the IL-6 neutralizing antibody-treated group. These results confirm the direct involvement of IL-1β, TNF-αand IL-6 in mouse NTN. We speculate that TGF-β1 may inhibit excessive proliferation in glomerular cells.

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The present study was designed to investigate the role of intercellular adhesion molecule (ICAM) -1 in the interaction between glomerular endothelial cells (GEN) and granulocytes. Expression of ICAM-1 was promoted after stimulation with tumor necrosis factor (TNF)-α. This effect was dose- and time-dependent. Granulocytes attached to GEN in accordance with the increased expression of ICAM-1 on the cells stimulated with TNF-α. In addition, the adhesion of granulocytes to activated GEN with TNF-αstimulated specific [⁵¹Cr] release from the monolayers. Furthermore, monoclonal antibodies to TNF-αdose-dependently inhibited the adhesion of granulocytes to acti-vated GEN. In summary, ICAM-1 is related to the glomerular endothelial cell injury induced by granulocytes activated with TNF-α, suggesting that ICAM-1 may play a role in the initiation of certain types of glomerulonephritis with granulocyte infiltration.

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Xanthine dehydrogenase (XDH) and xanthine oxidase (XO) are enzymes involved in the metabolism of purines in various organisms. XO produces superoxide radicals, suggesting that is responsible for tissue ischemia-reperfusion injury. To test this notion further studies were performed on rat kidneys and the time course of changes in purine nucleotides, oxypurines and XDH and XO activity was determined. At 24 hours after reperfusion subsequent to 30-minute ischemia, serum creatinine increased to 0.83±0.74 mg/dl from 0.28±0.06 mg/dl (the level prior to ischemia, the control). Renal ATP and ADP contents were reduced after ischemia lasting for 30 minutes and restored 10 minutes after reperfusion following 30 minutes of ischemia. The renal AMP content increased after 30 minutes of ischemia and recovered within 10 minutes after reperfusion. The total adenine nucleotide (TAN) content was reduced gradually during ischemia-reperfusion in the rat kidney. Although the energy charge was reduced following 30 minutes of ischemia, it was restored to the control level 10 minutes following reperfusion. Hypoxanthine (HX) and xanthine (X), which had accumulated at 30 minutes after ischemia, were reduced to the control levels 10 minutes after reperfusion. There were no signifi-cant changes in the pre-ischemia values of total XDH and XO activities or XDH/XO ratio during the period nor at various time intervals (up to 24 hours) during reperfusion. It was shown that HX and X accumulate without significant conversion of XDH to XO during ischemia. Therefore the putative role of XO in ischemia-reperfusion injury seems to more complex than initially predicted.

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To elucidate the impaired neutrophil function in patients with chronic renal failure, we analyzed the expression of the adhesion molecules, LAM-l, LFA-1, Mac-1, gp150/95 and phagocytosis activity of neutrophils in predialysis and hemodialysis patients by flow cytometry. Further, the response to granulocyte colony-stimulating factor (G-CSF), N-formyl-methionyl-leucyl-phenylalanine (fMLP) and tumor necrosis factor α (TNF α ) were investigated. In hemodialysis patients, the expression of LAM-1 was decreased and that of MAC-1 was increased, indicating the activation of neutrophils. Also in predialysis patients, the same condition of "low LAM-1, high MAC-1" was observed, but to a lesser degree. Phagocytosis activity was significantly decreased in hemodialysis patients, whereas the neutrophils of predialysis patients showed almost the same phagocytosis activity compared to the controls. The responses to G-CSF, fMLP, TNF a were significantly reduced both in hemodialysis and predialysis patients. The inadequate activation of neutrophils and impaired response to stimulation may play an important role in uremic patients with regard to increased susceptibility to infections.

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To clarify the role of genes related to angiotensin-Iconverting enzyme (ACE), the author investigated polymorphism of the ACE gene in 60 patients undergoing chronic ambulatory peritoneal dialysis (CAPD) and 50 patients undergoing hemodialysis (HD). One hundred healthy subjects were used as controls. The polymorphism was classified into three genotypes, II, ID and DD, according to insertion (I) and deletion (D) using the polymerase chain reaction method. In dialysis patients (CAPD or HD, n=110), 21.8% had the II genotype, 48.2% the ID genotype, and 30.0% the DD genotype. There was a significant difference in allele frequency between normal subjects (n=100) (I=0.63, D=0.37) and dialysis patients (1=0.46, D=0.54) (x ² =12.321, p<0.001). The mean plasma ACE activity was 9.9±1.6 IU/1 in CAPD patients with the II genotype, 11.6±4.7 IU/ 1 in CAPD patients with the ID genotype, and 14.5±3.5 IU/1 in CAPD patients with the DD genotype. The mean rate of decrease in residual urinary volume was 0.8±0.7% per month in CAPD patients with the II genotype, 1.4±1.3% per month in CAPD patients with the ID genotype, and 2.5 ± 2.0% per month in CAPD patients with the DD genotype. These data showed a significant decrease in urinary volume in CAPD patients with the DD genotype (p<0.05). The mean rate of decrease in residual urinary volume was positively correlated with the plasma ACE activity (r=0.13389, p<0.02). In CAPD patients, the mean cardiothoracic ratio was 46.6±3.5% in cases with the II genotype, 47.6±5.5% in cases with the ID genotype, and 52.9±8.4% in cases with the DD genotype. These data indicated significant cardiac enlargement in DD genotype cases. It can be concluded that CAPD patients with the DD genotype lost their residual renal function more rapidly and had a larger heart, than patients with the other genotypes.

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Since 1973, 15 patients, consisting of 8 boys and 7 girls, were diagnosed as having membranous nephropathy (MN). The average age at detection was 8.2 years (2-14 years). The presenting symptom was edema in 1, pyrexia in 1 and upper respiratory infection in 1 case, in the all other cases, abnormal urinalysis was detected by the school or chance urinalysis. Surface antigen of hepatitis B virus (HBs) was positive in 6 patients and negative in 9. Anti-nuclear antibody (ANA) was positive in 3 and negative in 11. In one patient, ANA was not tested. One patient who was negative for ANA was diagnosed as having SLE 4 years later. At the last follow-up, 10 patients continued to have urinary abnormalities. Among these was one case positive for HBs antigen who went into end-stage renal failure. In the other 14 patients, the serum creatinine level was below 1.4 mg/dl. All patients showed a normal mesangium or mild mesangial proliferation. The patient diagnosed as having SLE 4 years later showed mesangial deposits at the first renal biopsy. In our experience, most patients with MN were detected by the school or chance urinalysis and six of the these had positive HBs antigen. Lupus nephritis must be ruled out in making a diagnosis of idiopathic MN.

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We examined the effects of histamine H₂-receptor antagonists on the phosphorus binding ability of phosphate binders. Serum calcium, phosphorus, ALP, PTH and arterial blood pH and bicarbonate were measured during treatment with histamine H₂-receptor antagonists accompanied by calcium carbonate in sixteen patients undergoing maintenance hemodialysis. Seven patients receiving histamine H₂-receptor antagonists without calcium carbonate were selected as controls. In the sixteen patients receiving calcium carbonate, serum calcium, ALP, PTH and arterial blood pH and bicarbonate were not significantly altered during treatment with histamine H₂-receptor antagonists, but serum phosphorus levels increased significantly after four (5.6±1.1 mg/ dl) and eight weeks (5.9±0.8 mg/dl) of treatment as compared with that before treatment (4.8±1.2 mg/dl). Furthermore, serum phosphorus levels decreased significantly eight weeks after the discontinuation of treatment with histamine H₂-receptor antagonists. In the seven control patients there were no statistical differences in serum calcium and phosphorus levels measered before and after treatment with histamine H₂-receptor antagonists. In seven other patients receiving histamine H₂-receptor antagonists with calcium carbonate, calcium carbonate was replaced with calcium lactate as the phosphate binder after four weeks of treatment with histamine H₂-receptor antagonists. With the 4-week administration of histamine H₂-receptor antagonists accompanied by calcium carbonate, the serum phosphorus level increased, similarly to that of the first study (from 6.3±.9 to 7.1±0.5 mg/dl). However, with the substitution of calcium lactate, the serum phosphorus level decreased significantly (6.3±0.2 and 6.0±0.9 mg/ dl after four and eight weeks, respectively, despite continued administration of histamine H₂-receptor antagonists). These results suggest that histamine H₂-receptor antagonists significantly affect the phosphorus binding ability of calcium carbonate, but not of calcium lactate. Although the exact mechanism remains obscure, one possible explanation may be related to the rise in pH of the gastric juice. Careful observation of changes in the serum phosphorus level is required in hemodialysis patients receiving calcium carbonate and histamine H₂-receptor antagonists. Calcium lactate may be useful as a phosphate binder in such hemodialysis patients.

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Malnutrition is a serious complication in patients on long-term CAPD treatment. Accordingly, quantitative evaluation of nutritional status is a critical issue. This study aimed to assess nutritional status by dual photon energy x -ray absorptiometry (DEXA) in CAPD patients. Total lean body mass (D-TBM), right arm lean mass (D-RAM) and body fat percent (D-%FAT) measured by DEXA were compared with mid-arm muscle circumference (MAMC) and body fat percent (AP-%FAT) measured by anthropometrics (AP) in 51 CAPD patients. The subjects were stratified into groups by gender, age, duration on CAPD, and diabetes mellitus or non-diabetes. There was significant correlation between D-TBM, D-RAM and MAMC (r=0.519, p=0.001, r=0.545, p=0.001) or D-%FAT and AP-%FAT (r=0.763, p=0.0001). However, in the groups of females with over 50 years and over 48 months of dialysis duration, there was no correlation between D-TBM, D-RAM and MAMC. The DEXA method is useful in the quantitative evaluation of nutritional status of dialysis patients serially.

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Antihypertensive effects of beni-koji were studied using 29 outpatients with mild hypertension in a placebo-controlled double-blind comparative fashion. After a 4-week vehicle (apple juice) run-in period, 13 patients were assigned to receive beni-koji aqueous extracts containing juice once daily (27 g of beni-koji eq. per day) for 8 weeks and 16 were assigned to vehicle. Two patients assigned to the vehicle group did not complete the study. In addition to casual blood pressure, 24-hr non-invasive ambulatory blood pressure (ABP) was monitored in 6 patients given the beni-koji drink and 5 patients given the vehicle. 1) In the beni-koji group, both casual systolic and diastolic pressure decreased significantly during the treatment period (from 150±10/96±6 mmHg to 140±0/89±10 mmHg, p<0.01). The averages of the 24-hr blood pressure recorded in ABP (24-BP) also significantly decreased (from 141± 17/95±13 mmHg to 132±21 / 86±10 mmHg, p<0.05) when compared with those of the control period. Casual pressure normalized (less than 140/90 mmHg) in 4 patients who received beni-koji. Circadian variation of the blood pressure by ABP showed a significant decrease during the daytime. 2) In the vehicle group, casual systolic pressure did not change significantly (from 155±8 mmHg to 151±12 mmHg), but diastolic pressure decreased significantly (98±7 mmHg to 93±6 mmHg). Casual blood pressure did not normalize in any of the patients and 24-BP did not change significantly. 3) Summative evaluation of safety showed that no problems appeared in the beni-koji group. In conclusion, beni-koji appears to be an effective and safe food material for mild essential hypertension. The mechanism of the antihypertensive effect of beni-koji still remains to be investigated.

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Treatment with human recombinant erythropoietin (r-EPO) can dramatically improve renal anemia, whereas it has been reported that such improved anemia may involve or worsen hypertension. When we administered a single dose of r-EPO at 9, 000 units to 16 patients with end-stage renal failure requiring examination with a right cardiac catheter immediately before the introduction of dialysis, we measured cardiovascular dynamics and various vasoactive substances. The mean blood concentration of EPO was 3, 035 units/ml 15 minutes after administration. As compared with the value of 107.6±3.2 mmHg obtained before administration, the mean arterial blood pressure signifi-cantly increased following the administration of r-EPO to 111.5±3.8 mmHg after 5 minutes, 112.4 ±4.2 mmHg after 10 minutes, 113.7±4.3 mmHg after 20 minutes, and 113.6±4.3 mmHg after 30 minutes (p<0.05). The mean pulmonary arterial blood pressure tended to increase to 17.9±1.8 mmHg after 10 minutes from the level of 16.3±1.8 mmHg before administration (p=0.096). The pulmonary vascular resistance index (PVRI) was 165.0± 18.0 mmHg before administration and significantly increased to 193.2±19.0 and 199.0±16.6 dyn ⋅S bull;cm^-5bull;m² after 10 and 30 minutes, respectively (p<0.01, p<0.05). The systemic vascular resistance index (SVRI) also significantly increased to 2, 587±195 dynbull;Sbull;cm^-5bull;m² after 30 minutes from the level of 2, 454±207 dynbull;Sbull;cm^-5bull;m 2 before administration (p<0.05). Changes in SVRI showed a bimodal pattern, as with changes in PVRI. Angiotensin-IIconcentration significantly decreased to 13.7±4.4 pg/ml after 15 minutes from the level of 15.7±3.2 pg/ml before administration (p<0.05). There were no significant changes in endothelin, prostaglandin, or adrenaline concentration after the administration of r-EPO. From these results, it was revealed that pulmonary intra-arterial administration of r-EPO has the acute effect of increasing pulmonary vascular resistance, thereby pointing to a direct effect of r-EPO in pulmonary vasoconstriction. Although no changes in vasoactive substances were observed in the present investi-gation, further studies with more sensitive measuring methods may be necessary.

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Allopurinol is used freqently to treat patients with gout and hyperuricemia. However, adverse effects associated with this agent have been reported occasionally, especially among patients with hyperuricema complicated with renal diseases. A rise in the blood concentration of oxipurinol, the chief active metabolite of allopurinol, has been noted in patients with renal dysfunctions, pointing to an implication of oxipurinol in allopurinol toxicity. It has been reported that monitoring the serum oxipurinol concentration to maintain a level below 15.2 μ g/ml (=100μmol/ 1: recommended level) is helpful in avoiding toxicity. At Jikei University Hospital, a survey was conducted on 148 hyperuricemic patients who had been treated with allopurinol at the dosages of 50, 100, 200 and 300mg daily or 100mg on alternate days for more than one month. Because oxipurinol is an uricosuric substance, the steady-state serum oxipurinol concentration was determined by HPLC; and creatinine clearance (CCr) was calculated for each patient. 1. In the group composed of patients with normal kidney function (CCr≥80ml/min), increase in the dosage of allopurinol was associated with a linear increase in the serum concentration of oxipurinol. 2. Among the patients with varying renal function who were receiving 100mg of allopurinol daily, the oxipurinol level increased logarithmically as the creatinine clearance decreased. In some of the patients with renal insufficiency (CCr<30ml/min), daily administration of 100mg of allopurinol resulted in a serum concentration of oxipurinol over 15.2 t g/ml. 3. For patients with renal insufficiency (CCr<30ml/min), administration of allopurinol at the dosage of 50mg/day is considered adequate to avoid the accumulation of serum oxipurinol.

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