In order to evaluate the intracellular signaling pathway of endothelin 1 (ET-1), we examined mitogen-activated protein kinase (MAPK) cascade in cultured rat glomerular mesangial cells. Treatment of quiescent mesangial cells with ET-1 increased kinase activities toward bovine myelin basic protein (MBP). Maximal activation was at to min and ED₅₀ was about 5 nM. The 44-and 42-kDa kinases were activated in MBP containing gel kinase assay. These kinases were identified as extracellular signal regulated kinase (ERK) 1 and ERK2 with immunoblotting, respectively. MAPK or ERR kinase (MEK), one of the MAPK kinases, was present in rat mesangial cells and ET-1 also activated this MAPK kinase. These results indicate that MAPK kinase and MAP kinase are rapidly activated by ET-1 and may modulate cellular functions in rat mesangial cells.

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Cultured PTC cleary expressed intercellular adhesion molecule-1 (ICAM-1) under the influence of tubular basement membrane antigen (TBM)-primed lymphocytes. These TBM-primed lymphocytes also demonstrated a high cytotoxic activity against cultured PTC. A pure preparation of isolated PTC from BALB/c mouse kidney was brought into primary culture. PTC was prepared by the method of Boogaard PJ et al, and our modification. Briefly, kidney was perfused with buffer containing 0.08% (w/v) collagenase. The cortical tissue was then filtered through nylon-gauze. viable PTC were separated from other materials by isopycnic centrifugation on a discontinuous Nycodenz gradient. The confluent monolayer of PTC showed a typical epithelial morphology with cobblestone-like cells in the center of the cell-islands. Typical dome formation was observed in PTC cultures. These cells also strongly expressed r-glutamyl transpeptitase activity. Coculture of PTC with syngeneic lymphocytes primed with TBM antigen induced ICAM-1 expression in PTC. The TBM-primed lymhocytes had a cytotoxic activity without complement. However, neither virgin lymphocytes nor liver antigen-primed lymphocytes had cytotoxic activity. This simple syngeneic experimental model may allow us further molecular biological examination of renal tubulointerstitial diseases.

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This paper reports the ameliorative effect of Probucol (Pb) on ADR-induced nephrotic rats. Male Wistar rats underwent unilateral nephrectomy followed by one-week subsequent intravenous injection of 4.0mg/kg of ADR. The rats were then divided into 3 groups: Pb-treated, non-treated and the control. The control group received 0, 9% saline (vehicle) by injection. The 24-hr urinary protein excretion was measured for 24 weeks. When the animals were sacrificed at weeks 4, 12, and 24, respectively, blood samples were collected for biochemical study and the kidneys were extracted for measurement of malondialdehyde (MDA). In the morphological study, glomerular volume, glomerular sclerosis in dex (GSI), and tubulointerstitial index (TII) were calculated. Pb treatment lowered the serum lipid level and 24-hr urinary protein excretion. Total cholesterol was closely correlated with the urinary protein. However, there was no difference in terms of glomerular volume, kidney weight and GSI between the two groups. Pb treatment suppressed the kidney tissue MDA and TII significantly, the values of which were mutually correlated. The 24-hr protein excretion was significantly cor-related with TII, but not with GSI. The decreased proteinuria was explained on the basis of suppression of enhancement of intraglomerular pressure induced by interstitial lesion. The findings suggest that renoprotection of Pb may derive from the amelioration of interstitial lesions.

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We investigated factors affecting net transperitoneal calcium balance (Ca-BL) and the level of parathyroid hormone in relation to stepwise changes in serum calcium, by short PET (peritoneal equibrium test during 240 min: using 2000 ml of 2.5% dextrose dialysate containing 1.75 mmol/L Ca) in uremic patients undergoing stable CAPD. We calculated Ca-BL (mg/effluent/PET) of 244 effluents obtained from 90 patients receiving calcium carbonate as a phosphate binder without vitamin D supplementation. Their serum calcium level corrected with albumin (cSCa), alkaline phosphatase activity (ALP) and intact-PTH level was 9.7±0.9 mg/dl, 236±83 mIU/ml and 153.0±172.4 pg/ml, respectively. We proposed two statistic significant regression lines between Ca-BL and total drainage effluent volume (Ca-BL-133X-0.056: r=0.981, P<0. 001), cSCa (Ca-BL=-12.9X+123.6: r=0.941, P<0.01). Total drainage volume (TDV) and cSCa were two major factors affecting Ca-BL. A TDV level of 2430 ml/240 min-PET or more was required for positive Ca-BL in cases with 9.5-10.0 mg/dl of cSCa, using this linear regression analysis. A cSCa level of 9.6 mg/dl or more was also required for positive Ca-BL in cases with 2400-2600 ml/240min-PET. We also proposed a significant linear regression line between the intact-PTH level and cSCa (i-PTH- -90. 5X+1015. 8, r=0.973, P<0. 01). This line suggest that 200 pg/ml of intact PTH was obtained by 9.0 mg/dl or less of cSCa level in 90 CAPD uremic patients. However, this cSCa level was difficult to obtain through CAPD therapy with the dialysate used (Ca=1.75 mmol/L) for positive net transperitoneal Ca-BL. In conclusion, the 1.75 mmol/L calcium dialysate may have induced relative secondary hypoparathyroidism with low turnover bone in CAPD uremic patients receiving calcium medication as a phosphate binder. We recommend the replacement therapy with less concentrated calcium dialysate for CAPD patients without a high parathyroid hormone level.

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Inflammatory cytokines, including TNF-a, IL-1β and IL-6, have been reported to be responsible for acute or chronic complications and biocompatibility issues in dialysis patients have focused on the role of these cytokines. Expression of mRNA for TNF-α, interleukin (IL)-1β and IL-6 in peripheral blood mononuclear cells (PBMC) and their plasma concentrations was examined in 10 hemodialysis and 10 continuous ambulatory peritoneal dialysis (CAPD) patients. Plasma TNF-α and IL-1β levels in hemodialysis, CAPD and in every heathy subject were below the detection limits. Plasma IL-6 concentration was increased significantly in hemodialysis and CAPD patients when compared to normal controls (p<0. 01). Expression of mRNA for TNF-α, IL-1β and IL-6 in PBMCs was increased significantly (p<0.01) in hemodialysis and CAPD patients compared to normal subjects. These mRNA expressions were lower in CAPD patients than in hemodialysis patients (p < 0.05). Significant correlation was observed between the plasma IL-6 concentration and PBMC IL-6 mRNA expression in patients on hemodialysis or CAPD (p<0.01). IL-6 mRNA expression in PBMCs did not correlate with the duration of hemodialysis or CAPD, blood urea nitrogen (BUN) or serum creatinine levels. These findings suggest that mRNA expression indicates stimulation by dialysis procedures in patients, and CAPD is tolerated better than hemodialysis by patients with end-stage renal failure.

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We treated 90 pediatric patients with chronic renal failure with recombinant growth hormone (r-hGH) for 12 months to improve their growth retardation due to uremia. They were divided into two groups, non-dialyzed and dialyzed children. The dose of r-hGH was 0.5 or 1.0 IU/kg/week in dialyzed children. After 12 months of the treatment using r-hGH, growth velocity was significantly increased in any group of children. Growth velocity was stimulated to about twice as much as before treatment (that were: in non-dialyzed group, 4.2±2.6cm/year vs. 6.2±2.Ocm/year. P±0. 05, in dialyzed children treated with 0.51U of r-hGH: 2.7±1.8cm/year vs. 5.2±2.6cm/year, P±0. 001, and in dialyzed children treated with 1.OIU of r-hGH: 3.0±1.5cm/year vs. 6.3±2.2cm/year, P±0. 001). No severe side effects was noted and no disturbance of renal function. Our results were consistent with those reported from Europe and USA. We conclude that r-hGH treatment is very effective in improving retarded growth in children with renal disease.

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We treated 27 children with renal transplantation who showed growth failure due to deteriolated graft function and/or corticosteroids therapy with recombinant growth hormone (r-hGH) to improve their growth disturbance. The dose of rhGH was either 0.5 or 1.0 IU/kg/week. After 12 months treatment of r-hGH, growth velocity was significantly increased in both groups. Growth velocity was improved from 5.0±2.9cm/year to 7.7±2.3cm/year, P<0.05, in0.5IU group and 3.7±2.4cm/year to 6.3±3.3cm/year, P<0.05, in1.0 IUgroup. The most important side effect of r-hGH was relevant to graft function. 7 out of all 27 children showed deteriolation of graft function. However only 2 children showed significant decreases in their graft functin during r-hGH therapy. Thus we conclude that r-hGH therapy was effective to improve growth failure in uremic children even after renal transplantation due to poor graft function and/or corticosteroids therapy.

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A 34-year-old female patient was admitted to our hospital with a1-year history of chronic congestive heart failure, massive proteinuria and tibial edema. On admission, she presented with hemolytic anemia, hepatomegaly, splenomegaly and renal impairment. Furthermore, the skin of her face, hand, forearm, lower extremities showed crust and bulla. Laboratory examination revealed a large amount of protoporphyrin in her blood and feces, but no increase in urine. Light microscopy of renal biopsy showed moderate chronic tubulointerstitinal disease and mild proliferation of mesangial cells. The porphyians are a group of compounds associated with involving the disturbance of various biosynthetic heme pathway. Until now, the regulation of porphyrin and heme metabolism in the kidney have received relatively little attention as compared with those in liver and erythropoietic tissue. However, some recent reports have confirmed that proximal tubular cells may contribute to heme biosynthesis. It was strongly suggested that chronic tubulointerstitinal injury in this case might be directly induced by the disturbance of the biosynthetic heme pathway in the tubules.

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A 42-year-old female with progressive systemic sclerosis (PSS) developed rapidly progressive renal insufficiency. Renal pathology revealed crescentic glomerulonephritis (CrGN) without mucoid intimal proliferation of the interlobular arteries and fibrinoid necrosis of the afferent arterioles. Immunofluorescent micrography showed linear deposition of IgG along the glomerular capillary wall. Not only anti-glomerular basement membrane antibody (anti-GBM Ab), but also myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) were simultaneously detected by an enzymelinked immunosorbent assay (ELISA). She did not develop pulmonary hemorrhage. These findings were compatible with ANCA-related vasculitis and anti-GBM Ab nephritis. Laboratory findings showed rapid elevation of serum creatinine level (over 6.0m g /dl), a high titer of MPOANCA (660.7 ELISA unit/ml) and anti-GBM Ab (409 units). Therefore, she was started on methylp rednisolone pulse therapy and temporary hemodialysis. After immunosuppressive therapy, both antibodies titers had fallen to within the normal range. However, end-stage renal failure did not improve and maintenance hemodialysis was introduced. Recently, six patients of PSS with MPO ANCA were first reported in Japan. These autoantibodies detected in this case strongly suggested that there may be associations between anti-GBM Ab nephritis and ANCA-related vasculitis and PSS.

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