Guanidinoacetic acid (GAA), a precursor of creatine (CRT), which is synthesized by glycine amidinotransferase (GAT), is an essential substance for muscle energy metabolism and its production decreases as renal damage progresses, because the kidney is a main organ to synthesize GAA. To examine the metabolism of GAA and CRT in uremia, the author measured serum levels of GAA and CRT using HPLC in patients with chronic renal failure (CRF) and carried out animal studies. In the CRF patients under conservative therapy, serum GAA and CRT levels were lower than in the normal controls and there was a positive correlation between these parameters ([CRT]=16.4×[GAA]+85.0, r=0.510, p<0.01). On the other hand, serum GAA level in the patients under maintenance hemodialysis (MHD) increased to a similar level to the normals, however, serum CRT level increased exponentially in comparison with serum GAA (log [CRT]=0.025×[GAA]+2.10, r=0.613, p<0.01). In the CRF rabbits, serum levels of GAA and CRT were significantly lower and pancreatic GAT activity was significantly higher than in sham operated rabbits. Under the hypothesis that some antag-onistic substances to CRT might be taken into muscle tissue in uremia, β-guanidino-propionic acid (β GPA), which is one of CRT antagonist, was given to the rabbits. Urinary excretion of GAA and CRT, serum levels of GAA and CRT and pancreatic GAT activity were increased after j3 GPA load, as mimicked the changes of those parameters in the MHD patients. From these results, it is concluded that synthesis of GAA and CRT decreases in the course of renal damage, and the inability of the kidney to synthesize GAA may be com-pensated by the pancreas. And there might be present some substances to inhibit CRT uptake into the muscle cell in uremia, and that the serum CRT level increases expo-nentially as serum GAA recovers to the normal level in the MHD patients.

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We have already reported that renal glycine amidinotransferase (CAT) activity dec-reases in the course of renal damage, resulting in lower concentration of serum guanidin-oacetic acid (GAA) in the uremic stage, however, the inability of the kidney to synthesize GAA may be compensated by other organ(s), such as pancreas, in a more advanced stage of renal failure. From this point of view, we attempted to investigate the GAA metabolism in diabetic nephropathy. We measured the serum concentration of guanidino compounds in diabetic patients with normal renal function, chronic renal failure (CRF) on conservative therapy (CT) and maintenance hemodialysis (MHD) in comparison with non diabetic patients. Diabetics with normal renal function under insulin therapy showed a lower concentration of serum GAA and a significantly lower urinary output of GAA than diabetics without insulin therapy. In the period of CRF on CT, serum GAA concentration in diabetics was significantly lower than in non diabetics. In the period of CRF on MHD, serum concentration of GAA was similar between the two groups. Non diabetics in CRF on CT showed a significantly lower concentration of GAA than normal controls, and non diabetics in CRF on MHD showed a similar level to that in normal controls. Diabetics in CRF on CT showed a significantly lower concentration of GAA than diabetics with normal renal function, and diabetics in CRF on MHD showed a significantly higher concentration of GAA than those in CRF on CT, but the GAA concentration in MHD was significantly lower than that in normal controls. These results indicate that in diabetes mellitus, renal GAT activity is decreased from the period without renal dysfunction, and the extrarenal production of GAA is also dec-reased.

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In order to estimate the cellular immunedeficiency in patients with end-stage renal disease (ESRD), T cell colony formation and Interleukin-2 (IL-2) productivity were exa-mined using peripheral blood mononuclear cell (PBMC) from 9 patients. The patients were not yet undergoing hemodialysis therapy and their mean 24 hours creatinine clearance was 5.5±1.1 ml/min. Phytohemagglutinin (PHA) was used as mitogen for T cell colony formation in semi-solid culture. PBMC from patients with ESRD and healthy subjects were used for determination of IL-2 productivity. PHA was added to each PBMC, which was then cultured for 24 hours. The culture supernatant fluid was collected and added to IL-2 dependent cell obtained from T cell of healthy subject. After a 24-hour culture, ³H-thymidine was added for harvest 24 hours later. A decrease in peripheral blood lymphocytes was observed in the patients with ESRD. The T cell colony formation of the patients showed an evident decrease with that of healthy subjects (p<0.001). Addition of serum from the patients suppressed T cell colony formation in healthy subjects. IL-2 productivity in the patients was markedly lower than in healthy subjects (p<0.001). These results suggested that T cell function is impaired in patients with ESRD and that uremic serum has an effect on cellular immune response.

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120 hemodialyzed patients were studied to establish a non-invasive method for the diagnosis of Al-related bone disease and to determine the treatment efficacy of defero-xamin (DFO) administration for relief of bone pain. DFO in the amount of 40 mg/kg body weight was infused into the venous line during the last hour of dialysis session. Blood samples were collected at the start of the first and the next dialysis. Differences in serum Al concentrations of pre-DFO infusion and post-DFO were determined as ΔAl. In patients without bone pain, a signifficant correlation between ΔAl and dialysis duration was found (y=88.8+0.676x, n=49, r=0.55), but there was none between basal Al level and dialysis duration. Both basal and A A1 levels in patients with bone pain showed no signifficant correlation with dialysis duration. However, 63 out of 68 patients with bone pain placed above the regression line of those without pain. These data indicated the DFO loading test to be clinically applicable to the diagnosis of Al-related bone disease as a non-invasive diagnostic method. 63 patients on chronic dialysis complaining of continuous bone pain and whose ΔAl exceeded 150 μg/L were administered by DFO therapy. Δ Al rapidly decreased a mean average of 216 μg/L to 90 within 4 weeks. Complete or partial relief of bone pain was experienced by most of patients 4 to 6 weeks following the decrease of ΔAl. The treat-ment was effective for 89% of the patients. During the present study, side effects occured in 7.6% of the patients. One patient was diagnosed as perceptive deafness and the others liver dysfunction. In conclusion, the 2 g DFO loading test is a clinically useful non-invasive metnoa for diagnosis of Al-related bone disease. Several kinds of side effects were evident, but must be carried out with care and caution to relieve bone pain in the patients.

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By applying a preliminary treatment with non-polar resin (XAD-4) adsorption after ultrafiltration (1 KD) and a ‘hydrophobic’ HPLC system, nine of middle molecular sub-stances containing amino acids were isolated from hemofiltrates of a dialysis patient. To characterize uremic middle molecules, these substances were examined as follows: (1)the adsorption spectra (200-400 am), (2) the hydrophobicity in comparison with biologically active peptides, (3) the amino acid proportion and the detection of non-amino acid compo-nents, (4) the dansylation and the enzymatic hydrolysis. The results indicated that the spectral pattern and the hydrophobicity of these substances were dependent on structural features of non-amino acid components. And it was also clarified that the dansylation of amino acid residues in the molecules and the enzymatic hydrolysis of them were hard. This hardly digestible character in itself may lead to the retention of these middle mol-ecular substances in blood circulation of patient.

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Three fluorescent components found in the hydrolysate of hydrophobic middle mole-cules in hemofiltrates of a dialysis patient, were examined. Two components (F-12 & F-13) were fractionated from the acid-hydrolysate of a group of hydrophobic middle molecules, and the rest component (MH-14-11) was isolated from the hydrolysate of MH-14.0 middle molecule reported previously. λmax of these components in UV spectra were observed nearby at 230 nm and 350 nm. These spectra were in accordance with Type III of MH-14.0. On the three dimensional fluorescent spectra of both F-13 and MH-14.0, we observed their fluorescence developed at the same wavelength of Ex 340 nm and Em 520 nm. And also, another fluorescent spectrum at Ex 250 nm and Em 480 nm developed in MH-14.0 was similar to the known fluorescence of uremic substances. FAB-MS of F-12 and F-13 indicated the same spectra with major fragment signals and molec-ular mass ion (897) that might suggest a possibilty of same molecular speices with common basal composition. We confirmed that these fluorescent components in uremic middle molecules had middle molecular weight.

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The sequential changes in 24-hour urinary norepinephrine (NE) and epinephrine (E) excretion values were measured in spontaneously hypertensive rats (SHR) receiving deo-xycorticosterone acetate (DOCA) and 1% NaCI drinking water and were compared with control SHR. These data were also compared with Wistar-Kyoto rats (WKY) similarly treated. Blood pressure and NE and E increased progressively in DOCA-SHR, and NE (2392±94 vs. 998±49 ng/day) and E (250±21 vs. 116±6 ng/day) exceeded twice that of the control SHR in the sixth week of DOCA treatment. In WKY NE (1372±48 vs. 968±37 ng/day) and E (147±9 vs. 121±7 ng/day) were significantly higher in DOCA than in control group in the sixth week of the treatment, but were not so remarkably high as in DOCA-SHR. Histological examination of the kidneys of DOCA-SHR revealed fibrinoid necrosis in the vascular walls. These data suggested that sympathetic-adrenal medullary activity played an important role in the development of malignant hypertension in DOCA-SHR.

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To study the factor controlling the release of atrial natriuretic factor (ANF), peri-pheral plasma ANF concentrations were measured in 45 patients with heart disease who underwent cardiac catheterization. In anaesthetized and intubated dogs, the release of ANF was also studied in response to increases in pulmonary arterial (PA) pressure. A highly significant positive correlation between plasma ANF concentration and PA pressure (systolic, r=0.89; diastolic, r=0.79; mean, r=0.88; each p<0.001) was found in all patients. Significant positive correlations were also found between plasma ANF concentration and systolic right ventricular pressure (r=0.84, p<0.001), right ventricular end-diastolic pressure (r=0.44, p<0.01) and pulmonary capillary wedge pressure (r=0.35, p<0.05). Significant negative correlations to plasma ANF concentration were found for mean aortic pressure (r=-0.32, p<0.05), cardiac index (r=-0.46, p<0.01) and stroke volume index (r=-0.33, p<0.05). The positive correlation between plasma ANF con-centration and PA pressure was significantly higher than that between plasma ANF concentration and pulmonary capillary wedge pressure. There was no significant corre-lation between plasma ANF concentration and mean right atrial pressure. Plasma ANF concentrations in primary pulmonary hypertension were very high inspite of their normal left atrial pressures. In anaesthetized dogs, elevation of mean PA pressure (about 1.5 mmHg) without a significant change of right atrial pressure by inflating the balloon positioned in unilateral pulmonary artery caused a significant increase in plasma ANF concentration in main pulmonary artery (basal, 51.1±11.1 (SD)pg/ml; maximal, 99.9±36.3 pg/ml, p<0.01; n=7). However, the elevation in plasma ANF concentrations in response to increased PA pres-sure was completely blocked by bilateral cervical vagotomy (n=6). There were no significant changes in heart rate and hematocrit during the experimental period. These findings suggest that PA pressure may play an important role in the mechanisms of ANF release from cardiac atria and ANF release in response to increased PA pressure may be caused through a neuronal reflex arc.

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The characteristics of cyclic AMP phosphodiesterase (PDE) bound to renal brush border membrane (BBM) was investigated, since there was possibility that the enzyme was associated with the function of BBM affected by hormones. BBM was purified from rat renal cortices by Mg²⁺precipitation and porous glass-beads column chromatography. The optimal pH of the enzyme activity was 7.0 and the activity was inhibited by 5 mM EDTA and EGTA. Kinetics analysis of the enzyme indicated exists two forms of PDE with Km of 3.6×10^-6 M and 3.0×10^-5 M. Na⁺ dependent phosphate uptake by brush border membrane vesicles was decreased when the membrane was phosphorylated with hypotonic solution in the presence of 5 mM theophylline. One hour after intravenous injection of 10 U 1-34PTH to parathyroidectomized rats, Km of PDE in BBM was 4.8×10^-5 M and low affinity form of the enzyme was stimulated. PDE activity of BBM obtained from the rats with chronic renal failure by glycoprotein injection, was signifi-cantly elevated and kinetic study showed an increase of V max in both forms of PDE. These results indicated that PDE in BBM would be closely related to phosphate transport through the degradation of cAMP.

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Glomerular thrombosis was successfully induced in rats by the injection of 0.2 ml of nephrotoxic antiserum 24 hours prior to the injection of 0.02 mg of lipopolysaccharide. All of experimental rats showed fibrin deposit in glomerular capillaries by the evaluation of both hematoxylin-eosin and fluorescent stainings, however, any thromboembolic lesions were not present in other organs such as lung, liver and intestine. Since some of these rats could be alive more than 60 days, it was possible to evaluate the long-term histo-logical changes after the induction of experimental glomerular thrombosis. Fibrin deposit was transient, and localized in segmental within one week. The number of circulating leukocytes and platelets, the value of plasma fibrinogen and Factor VIII activity were rapidly decreased during first 7 hours and recovered within 24 hours, while the value of serum FDP showed the transient increase. After 5 days of acute fibrin deposit, cell proliferation in glomeruli and crescent for-mation appeared and increased progressively until 2 months later, when 50% of glomeruli showed crescent formation. The experimental glomerular thrombosis can be a useful model for the evaluation of the pathogenesis of glomerular proliferation including crescent formation as well as glomerular thrombosis.

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Utilizing polyclonal antibodies to fibrinogen/fibrin related antigens (FRA), factor VIII related antigen (vWf : Ag), factor XIII subunit-A (F. XIII-A) and platelet membrane antigen (PMA), immunoelectron microscopy (IEM) was performed on kidney tissues from 2 normal humans and 41 patients with various renal disases. In normal human kidneys, FRA deposition was present only in the capillary lumen, and vWf : Ag was detected in the endothelial cells, but F. XIII-A and PMA were negative. On the tissue from patients with renal diseases, FRA was deposited in almost all cases; FRA were positive in the glomerular capillaries and mesangium of patients with Henoch-Schonlein purpura nephritis (HSPN), crescentic GN (crGN) and lupus nephritis, indicating the association between mesangial FRA deposition and mesangial proliferation. In contrast, the localization of FRA was restricted to capillary lumens in minimal change nephrotic syndrome (MCNS) and hemolytic-uremic syndrome (HUS). VWf : Ag was fre-quently localized in the mesangium and glomerular endothelial cells. F. XIII-A was deposited dominantly in the glomerular capillary lumens. PMA was present with glomeruli of 50% of patients. FRA, vWf : Ag and F. XIII-A was generally co-deposited in the glomerular capillary lumens, and FRA and vWf : Ag were deposited in the mesangium of IgA nephropathy, HSPN, membrano-proliferative GN and crGN, suggesting the local activation of the coag-ulation system. FRA deposition was occasionally dissociated with vWf : Ag or F. XIII-A, which is probably due to non-specific trapping of fibrinogen or difference in the clearance mechanism of each coagulation protein.

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It has been reported that rifampicin attenuates an effect of corticosteroid. We observed nonresponsiveness to prednisolone treatment during rifampicin administration in a case of adult nephrotic syndrome. A 21 years old man had the onset of facial edema and ascites in and was diagnosed as nephrotic syndrome (minimal change) at a certain hospital. He was treated with prednisolone and obtained complete remission. He had the complaint of chest pain in May 1984, and was transfered to our hospital. We diagnosed him as nephrotic syndrome and tuberculous pleuritis. We administered him isoniazid 300 mg/day, rifampicin 450 mg/ day, streptomycin 3 g/week and prednisolone 30 mg/day. His urinary protein was not decreased. Subsequently, we administered him predonisolone 60 mg/day. But his urinary protein was not changed. We thought that rifampicin might attenuate the effect of pre-dnisolone. After rifampicin was discontinued, urinary protein was decreased rapidly. He obtained complete remission and was discharged from our hospital. It was reported that a patient with Addison's disease required increased corticosteroid dosage whilst receiving rifampicin and had cortisol catabolism following hepatic microzomal enzyme induction by rifampicin. Our case of nephrotic syndrome showed the nonresponsi-veness to prednisolone treatment during rifampicin administration. The corticosteroid is essential to treatment of nephrotic syndrome and collagen disease, and rifampicin is an important drug in treatment of tuberculosis. We should pay attension to drug interac-tion between corticosteroid and rifampicin in the cases with combination of these drugs.

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The reports of purpura nephritis in senile patients are few. We experienced a senile case of Schönlein-Henoch's purpura complicated purpura nephritis. Here, we report this rare and interesting case. The patient was a 67-yr-old man. Purpura appeared on his limbs after he caught a cold. On to have further examination for his purpura, he admitted to the department of dermatology, He was diagnosed as anaphylactoid purpura by skin biopsy. Later abdominal pain and arthralgia appeared. Because of the appearance of proteinuria, hematuria and many urinary sediments, he transferred to the second department of internal medicine of the same hospital. At the admission, marked proteinuria and many red blood cell, hyaline casts, tatty casts, oval fat body, and fatty granules appeared on urinalysis. IgA increased in immuno-globulins. He underwent renal biopsy. In his kidney tissue, light microscopic finding revealed mesangeal proliferation and mesangeal interposition. In immunofluorescence examination, IgA was deposited at mesangeal region. In electron microscopic finding, electron dense deposit was found at mesangeal and subendothelial legion. From these examination, he was diagnosed Schönlein-Henoch's purpura nephritis. He was the oldest case in whom renal biopsy were performed on the diagnosis of this disease.

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A 47-year-old woman was found to have proteinuria in She was admitted to our department, complaining of dizziness and proteinuria in Physical examination revealed weak artery pulsations in left upper limb and bilateral lower limbs, although there was no laterality of blood pressure. The blood pressure was 140/80 mmHg in the right upper limb. In the neck, no bruit was heard. The heart was slightly enlarged, and systolic murmur was audible in the 2nd left sternal border and the apex. In the abdomen, a bruit was heard. The urinalysis showed 3(+) for protein, (±) for occult blood. The serum enzymes and total protein were also within normal limits. The serum electrolytes and the renal function were within normal limits. ESR was 58 mm/I hr, 94 mm/2 hr. CRP, RA, LE test, LE cell, and ASLO were negative. The other immuno-logical data were: positive antinuclear antibody (1: 40), positive anti-DNA antibody (39.7 U/ml), C3 43 mg/dl, C4 12 mg/dl, circulating immune complex 58 microgram/ml. The digital subtraction angiography demonstrated the narrowings in the upper branch of the left pulmonary artery, the aorta at the level from Th12 to L1, and the right renal artery, which were suggestive of aortitis syndrome (Takayasu's arteritis). A renal biopsy revealed thicking of the capillary wall with mild mesangial proliferation on light micro-scopy. Immunofluorescence study disclosed granular deposits of IgG, IgA, IgM, Clq, and C3 in the capillary wall and mesangial area. Electron microscopy revealed electron-dense deposits in the subepithelial and mesangial area (Stage II). The serological data and the renal histological findings were suggestive of lupus membranous glomerulonephropathy. Thus the present case was diagnosed as aortitis syndrome (Takayasu's arteritis) associated with glomerolonephropahy mimicking lupus membranous glomerolonephropathy, and sug-gested that there might be some immunological disorder common to these two diseases.

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