The accumulation of mesangial matrix is a common histologic abnormality observed over the course of various glomerular disease. To determine the role of growth factors in the mesangial matrix metabolism, the effects of the transforming growth factor-β(TGF-β), interleukin-1β(IL-1β), platelet-derived growth factor (PDGF), epidermal growth factor (EGF), endothelin (ET), and insulin-like growth factor (IGF) on the gene expression of mesangial matrix were studied in cultured rat mesangial cells (MCs). TGF-β induced transcriptional activation of the genes for α 1(I) and al (IV) collagens and fibronectin, and the mRNA levels for these genes in MCs treated with TGF-β for 24 hours resulted in 1.9-, 2.8-, 2.6-fold increase, respectively, compared to their basal levels. IL-1β also transcriptionally increased the mRNA levels for α1(I) α1(IV) collagens and fibronectin in the non-stimulated MCs, however, inhibited the increase of these mRNA levels in the TGF-β-treated MCs. MCs showed little increase in the gene expression for αl (IV) collagen and fibronectin by the addition of PDGF, EGF, and ET, and no change was noted in the IGF-treated MCs. Detectable gene expression for B1 chain of laminin and heparansulphate proteoglycan was observed in the non-stimulated MCs but small in intensity, and no change was noted by stimulation of any growth factors examined. These results suggest that TGFβ and IL-1β, which are released in glomerular injury, induce alteration in the gene expression of the al (I)and αl (IV) collagens and fibronectin in MCs, and may affect the mesangial matrix metabolism.

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The intracellular content of cyclic GMP (cGMP) is known to mediate the effects of various vasodilating substances on glomerular mesangial cells. However, little is known about the role of soluble guanylate cyclase (SGC) in these cells in diabetes. We, therefore, investigated the changes in SGC activity as well as the cGMP content in rat mesangial cells (MC) cultured under high glucose or hypertonic conditions. The following results were obtained. 1. Sodium nitroprusside (SNP) (10^-4M, 10min. ) increased cyclic GMP (cGMP) content in MC from 8.17±0.99 pmol/mg protein to 981.6±86.3. 2. SNP(10^-4M) stimulated SGC activity from 38.3±10.8 pmol cGMP formed/mg protein/lOminutes to 74.4±5.2. 3. In the coincubation experiment with bovine aortic endothelial cells, bradykinin (10^-6M, 10min.) increased cGMP content in MC from 6.24±1.35 to 348.3±45.3. However, 4. the activity of SGC and SNP-induced increase of cGMP were not influenced by culturing MC in high glucose or hypertonic media. Similarly, the cGMP increase in MC coincubated with BAEC under bradykinin stimulation was not altered by culturing under high glucose or hypertonic conditions. These data suggested that SGC may play an important role in the regulation of cGMP content in MC. However, this enzyme may not be involved in the increase of cGMP content in MC cultured under high glucose condition.

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To elucidate the role of reactive oxygen species (ROS) in accelerated nephrotoxic nephritis (NTN), effects of SOD-mimic (Fe-TPAA) and anti-PAF (WEB-2086) on NTN were investigated. Three days after the preimmunization with normal rabbit IgG, anti-GBM rabbit IgG were administered unilaterally to the left kidney in order to examine the effect of circulating inflammatory factors by comparing with the contralateral kidney. Normal rabbit IgG were likewise injected to the control rats. Luminol amplified chemiluminescence (CL) assay of isolated glomeruli, histological examination and monoclonal antibody (anti LC-A Ab, anti PMN Ab, anti Mφ Ab) positive-cell counting were performed in both kidneys. After induction of NTN, 3.4mg/kg/day of Fe-TPAA and 2mg/kg/day of WEB-2086 were respectively administered by continuous injection using Osmotic pump. At day 7, glomerular CL and glomerullar cellularity were both increased significantly in anti-GBM perfused kidney. Anti-rabbit IgG were also stained in the contralateral kidney, but clearly in lesser amount as compared with the anti-GBM perfused kidney, suggesting very slight glomerulonephritis may have occurred also in nonperfused kidney. While WEB-administration suppressed glomerular hypercellularity, CL and urinary protein, Fe-TPAA administration did only glomerular CL. Taking into account that dosing amount of Fe-TPAA was limited due to its toxicity, the effective ROS scavenging may not have been obtained. However, another possibility is proposed that WEB-2086 suppressed the development of glomerular lesion by not only inhibiting generation of ROS but also by release of other inflammatory factors.

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To determine whether recombinant human erythropoietin (rHuEPO) has direct effect on mean arterial pressure or renal function, rHuEPO was infused intrarenally at a rate of 100 U min^-1 for 30 min in anesthetized rabbits without renal failure . Intrarenal infusion of rHuEPO resulted in no change in mean arterial pressure, renal blood flow, or renal vascular resistance as compared with vehicle control. rHuEPO also produced no significant change in glomerular filtration rate, filtration fraction, or arterial hematocrit. However, urine volume, urinary excretion of sodium and potassium, and fractional sodium excretion were significantly reduced by intrarenal infusion of rHuEPO. These observations demonstrate that rHuEPO has no direct effects on mean arterial pressure or renal hemodynamics, whereas rHuEPO stimulates net tubular sodium reabsorption possibly by direct tubular action, and reduces urine volume and urinary excretion of sodium and potassium in anesthetized rabbits without renal failure.

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Monoclonal antibodies (Mo-Abs) were prepared by fusing mouse myeloma cells (PAT) with spleen cells of mice immunized with Tamm-Horsfall glycoprotein (THGP). Six Mo-Abs screened for the presence of anti-THGP antibodies by enzyme linked immunosorbent assay and by immunoblotting assay have been produced. The specificity studies clearly indicated that the Mo-Ab individualized four distinct epitopes. The immunofluorescent reaction by the Mo-Abs have been analyzed in the human kidney section with normal or a minimal change. The No. 1, 2, 3 and 5 of Mo-Abs reacted with the cytoplasm of distal convoluted renal tubules, while the No. 4 and 6 of Mo-Abs reacted with a substance in the capsular space as well as with the cytoplasm of distal convoluted tubules. The sites of synthesis of this substance, detected in the capsular space by No. 4 and 6 of Mo-Abs and holded the immunological cross-reactivity with tubular THGP, is presently uncertain. The specificity of the Mo-Ab may be of considerable value for further studies.

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We studied about the histological findings of the kidneys including of the infiltrated macrophages in one hour post-transplantation kidney biopsies (one hour biopsies) and re-biopsies on 11 patients. They were transplanted at 4-28 (ave. 15.1±3. 8) years of age. The periods from transplantation to this study were 1.0-7.3 (ave. 3.3±1.9) years. 6 patients had acute rejections, and their renal function became normal after treatments. At this study, all grafts servived, and the patients had no abnormal findings except two (one had proteinuria, another had proteinuria and mild elevation of serum creatinine level). But histlogically, five patients had chronic rejections among the 8 patients who had re-biopsies more than one year after transplantations. And we experienced 6 patients whose kidney had mesangial IgA deposits in one hour biopsies and 3 patiens who had de novo type glomerulonephritis in re-biopsies (IgA nephropathy in 2 patients, membranous nephropathy in one). In one hour biopsies, the populations of macrophages in the interstitium were 4.18±2.84/mm² in the patients who would have acute rejections (6 patients), 1. 38± 1. 13/mm² in the cases who would not have. It was suspected that the increase of the infiltrated macroph-ages in the interstitium in one hour biopsies could predict acute rejections. In re-biopsies, many macrophages infiltrated in the interstitium (8. 34 ±4. 86/mm²), particularly on patients who had chronic rejections.

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Peripheral blood monocytes(PBM) and T cells from patients with membranoproliferative glomerulonephritis (MPGN) and poststreptococcal glomerulonephritis (PSAGN) were measured for the production on C3 and interferon-γ respectively using an enzyme-linked immunosorbent assay. Testing of h4PGN and PSAGN patients at acute stage showed that C3 levels by PBM were significantly higher than those of normal controls, whereas the levels of PSAGN patients at convalescent stage dropped within the range of normal controls . Levels of C3 production by PBM inversely correlated with serum C3 in both MPGN and PSAGN patients. Interferon-γ production by T cells of MPGN patients were significantly higher than those of normal controls, while in PSAGN patients the levels, although not significantly elevated at acute stage, increased significantly at convalescent stage . These results suggest that hyperproduction of C3 by PBM in both hypoC3 disorders is likely due to activation of the cells by not yet determined antigens or immune complexes, but the effects of T cells on the activated PBM in MPGN differ from in PSAGN patients probably due to distinct antigens or immune complexes.

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Risk factors for contrast nephropathy were prospectively studied in 17 patients with non-insulin dependent diabetes mellitus undergoing cardioangiography. Contrast nephropathy, defined as a serum creatinine increase of greater than 25% at 3 day after angiography, occured in 29.4% of diabetic patients. Patients who developed contrast nephropathy had significantly higher serum creatinine (Cr), fractional excretion of sodium (FENa), urinary albumin excretion rate (AER), and lower 24hrCcr than patients who did not (Cr:1.5±0.3mg/ dl vs. 0.8±0, lmg/dl, FENa: 1.9±0.5% vs. 0.6±0.1%, AEI: 522±335 jig/mmn vs. 27±13 jig/ min, 24hrCcr: 39.1±11.6m1/min vs. 86.2±9.3m1/min, P<0. 05). Contrast nephropathy devel-oped in all of two patients with overt proteinurea (AER more than 200 μg/min), but none of eight patients with normoalbuminuria (AER below 15 μg/min). Three of seven patients with microalbuminuria developed contrast nephropathy, and two of them had advanced nephropathy. FENa obtained next day was significantly elevated over baseline in patients with contrast nephropathy (1.9±0.5% vs. 9.7±4.5%, P<0.05), but unchanged in patients without contrast nephropathy. The rise in Cβ2microglobulin/Ccr and enzymuria was noted in both group. Percentage decrease of Ccr on the next day was positively correlated with FENa before angiography (r=0.645, p<0.01). Of 24hrCcr, AER, and FENa before angiography, FENa was revealed as a statistically significant discriminant factor for contrast nephropathy by stepwise discriminant analysis (p=0.0008). These results suggest that contrast nephropathy develops predominantly in the stage not of incipient but of overt diabetic nephropathy indicated by a decline of glomerular filtration, overt proteinurea, and tubular dysfunction. Of them, tubular dysfunction may be the most important risk factor for contrast nephropathy.

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In order to examine the efficacy and safety of long-term erythropoietin (rHuEPO) therapy, 103 hemodialysis patients were treated with rHuEPO for their renal anemia and the effects were observed for 1 year. Within 3 or 4 months after starting the rHuEPO therapy, the hematocrit (Ht) value rose up to nearly 30% and the level was maintained thereafter by approximately 4500 IU per week of rHuEPO. Tachyphylaxis did not occur even after 1 year of rHuEPO treatment. Symptoms such as headache, dizziness or palpitation were markedly reduced with the improvement of anemia. Although blood pressure was modestly elevated (systolic by 9 mmHg, p<0. 01 and diastolic by 5 mmHg, p<0. 01 at 6-month-stage), only 1 patient was forced to stop the therapy. Moreover, the blood pressure was successfully controlled to the original level after 11 months. This blood pressure elevation was not related the increase of Ht level nor the dose of rHuEPO. Serum protein, lipid, electrolytes and liver enzymes did not change during 1 year of rHuEPO therapy. These results indicate that rHuEPO treatment is effective and innocuous as a long-term therapy of renal anemia in hemodialysis patients.

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To clarify the effects of correction of anemia with recombinant human erythropoietin (rHuEPO) on blood coagulation, fibrinolysis and endothelium, these markers were examined in 19 regular hemodialysis patients before and 4, 8, 12 weeks on rHuEPO treatment, and 5 weeks after the end of treatment. Hematocrit significantly increased from 22.8±2.0 to 31.1± 2.7% at 12 week (p<0.001). Coagulation and fibrinolysis markers did not show significant changes except for minor and transient alteration of protein C, thrombin-antithrombin III complex and a2-plasmin inhibitor plasmin complex (PIC) throughout the treatment. Endotheline and 6-keto-prostaglandin F1α (PGF1α) significantly increased from 6.1±4.5 to 14.2±2.9 pg/ml (p<0.001) and from 51.9±14. 7 to 66.5±18. 5 pg/ml (p<0.05) at 12 week, respectively. Human atrial natriuretic peptide (ANP) significantly decreased from 277.9 ± 88.6 to 179.4±73.3 pg/ml at 12 week (p<0.001). Endotheline and PGF1a after 6 month treatment with rHuEPO showed high values as same as those of 12 weeks. These data suggests that rHuEPO therapy did not affect blood coagulation and fibrinolysis, however exerts effects on the endothelium. Changes in endothelial function after rHuEPO may be one of the pathogenetic mechanisms of hypertension and may contribute to a decrease in thrombotic complications.

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A case of Behcet's disease with IgA nephropathy was reported in a 17 year old man. He presented with microscopic hematuria which was pointed out by urinary mass screening for school children at age of 14. As he was subsequently evoleved proteinuria, a renal biopsy was performed at age of 16. The specimen showed diffuse proliferation of mesangial cells. Immunofluorescent studies showed granular deposition of IgA. At age of 17, he showed typical symptoms of Behcet's disease, namely aphtous stomatitis, perianal ulcers, erythema nodosum-like lesions, uveitis and genital aphtha. Furthermore he showed an increasing of proteinuria and an impairment of his renal function. Serum IgA level and immune complexes during the exacerbation stage were elevated. The uveitis markedly improved with ciclosporin A therapy. Reduction of proteinuria and improvement of renal function were simultaneously observed. These findings may suggest that IgA nephropathy and Behcet's a disease have common immunological pathogenesis, including circulating immune complexes.

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We have recently found that allogenic bone marrow transplantation (BMT) can be used to treat lupus nephritis in NZB×NZW Fl (B/W Fl) and BXSB mice. To elucidate why and how glomerular damage is repaired, serial renal biopsies were carried out using B/W Fl mice before, and after BMT. Donor-derived B cells and macrophages with normal functions developed two weeks after BMT, whereas donor-derived functional T cells were generated after seven weeks of BMT. Visceral epithelial cells as well as macrophages in the glomeruli were activated (probably by T cell-derived lymphokines) at this time; they showed marked phagocytic activity, resulting in clearance of immune complexes (ICs) and repair of damaged basement mem-branes. These results suggest that normal T cell functions, which have the capacity to activate macrophages and epithelial cells, are essential in repairing IC-mediated glomerular damage.

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