Secondary erythrocytosis associated with distal renal tubular acidosis

AIMS

Diagnosis and classification of renal tubular acidosis (RTA) have traditionally been made on the basis of functional studies. Despite recent expanding knowledge about the molecular abnormalities involved in renal bicarbonate (HCO3-) and H+ transport, the pathophysiology of secondary erythrocytosis in association with distal RTA remains obscure.

CASE HISTORY

A 2-month-old boy with severe hyperchloremic metabolic acidosis with positive urine anion gap was diagnosed with distal RTA. Replacement therapy with sodium bicarbonate and potassium citrate succeeded in improving his metabolic acidosis and growth. His renal function remained normal. He had persistent erythrocytosis.

CONCLUSION

Secondary erythrocytosis is a rarely reported association of distal RTA. It may increase the risk of thromboembolism.

Focal segmental glomerulosclerosis associated with acromegaly

Experimental studies in rats have demonstrated an association between focal segmental glomerulosclerosis (FSGS) and growth hormone, but patients with FSGS complicating acromegaly are very rare. In this report we present a case of FSGS associated with acromegaly. With a long history of soft tissue swelling of hands and feet, elevated plasma growth hormone levels and other biochemical abnormalities, a 53-year old male had suffered from acromegaly for over 15 years. He had moderate proteinuria for 6 years, but never evidenced nephrotic syndrome. A renal biopsy specimen revealed FSGS and glomerular hypertrophy. Trans-sphenoidal surgical removal of the pituitary adenoma resulted in the normalization of elevated growth hormone and insulin-like growth factor I levels, but proteinuria continued. This case suggests that the overproduction of growth hormone may participate, at least in part, in the development of human FSGS. It is possible that once FSGS is present in an acromegalic patient, cessation of GH overproduction may not be enough to reverse it.

Increased insulin sensitivity and decreased insulin secretion in offspring of insulin-sensitive type 2 diabetic patients

To investigate the early defects of glucose metabolism in insulin-sensitive type 2 diabetes, we performed oral and frequently sampled intravenous glucose tolerance tests (OGTT and FSIGT) with minimal model analysis in 15 offspring of Japanese type 2 diabetics with normal insulin sensitivity (insulin resistance index of homeostasis model assessment [HOMA-R] < 2.0) and in 20 healthy control subjects without a family history of type 2 diabetes. The frequency of impaired glucose tolerance (IGT) was 40% (6 of 15) in the offspring and 0% (0 of 20) in the controls. Fasting plasma glucose (4.8 +/- 0.1 v4.6 +/- 0.1 mmol/L, P = .18) and immunoreactive insulin ([IRI] 29.9 +/- 2.5 v 28.3 +/- 2.5 pmol/L, P = .64) were comparable between the offspring and the controls. The rate of glucose disappearance (KG) was significantly lower in the offspring versus the control group (2.00 +/- 0.22 v 2.60 +/- 0.17 min(-1), P= .03). The insulin sensitivity index (Si) was significantly greater in the offspring versus the controls (2.68 +/- 0.41 v 1.71 +/- 0.17 x 10(-4) min(-1) x pmol/L , P = .02). First-phase insulin secretion (FPI) to intravenous glucose was significantly lower in the offspring versus the control group (886 +/- 110 v 2,296 +/- 267 min x pmol/L, P< .01). Glucose effectiveness (SG) was comparable between the offspring and control groups. The disposition index (Si x FPI) was significantly lower in the offspring versus the controls (2,106 +/- 256 v 3,652 +/- 490 x 10(-4), P = .02). When the offspring were subdivided into 2 groups by glucose tolerance status, both normal glucose tolerance (NGT) offspring and IGT offspring showed a significant decrease in FPI and increase in Si. Thus, although the offspring of insulin-sensitive type 2 diabetics had increased insulin sensitivity, the impairment in insulin secretion was more dominant. Our results suggest that the early metabolic abnormality in insulin-sensitive type 2 diabetes is an insulin secretory dysfunction despite increased insulin sensitivity.

Effect of the platelet-derived growth factor antagonist trapidil on mesangial cell proliferation in rats

Platelet-derived growth factor (PDGF) is known as a potent mediator in the proliferation of mesangial cells in culture and in mesangial proliferative nephritis. The present study was undertaken to evaluate the effect of trapidil, an antagonist of PDGF, on mesangial cell proliferation in culture and in anti-Thy-1.1 nephritis in rats. Trapidil significantly inhibited 3H-thymidine incorporation in the mesangial cells stimulated by PDGF BB and suppressed mesangial cell proliferation in culture in a dose-dependent manner. In anti-Thy-1.1 nephritis, a significant reduction in the number of total glomerular cells and also proliferating (proliferating cell nuclear antigen positive) cells was demonstrated on day 7 in the rats treated with trapidil as compared with controls. Although renal function expressed as blood urea nitrogen and creatinine levels did not differ between rats with and without trapidil treatment, the present results suggest a salutary effect of trapidil on mesangial cell proliferation. PDGF, therefore, could play an important role in mediating mesangial cell proliferation.

Evaluation of insulin response in glucose tolerance test in a patient with Werner's syndrome: a 16-year follow-up study

To clarify the effect of Werner's syndrome (WS) on beta-islet cell function, the oral glucose tolerance test (OGTT) was repeatedly performed over a period of 16 years in one patient with WS. The data obtained on insulin secretion were assessed in this study. The patient was a 50-yr-old woman of consanguineous parentage. She presented with gray hair, cataracts, a beak-shaped nose and high-pitched voice. She was diagnosed as WS on the basis of her characteristic appearance. OGTT was performed 14 times during 9 admissions to our hospital. After ingestion of glucose, plasma glucose (PG) levels and immuno-reactive insulin (IRI) at 0, 30, 60, 90, 120 and 180 min were determined. PG levels during OGTT gradually increased during dietary therapy and, at the age of 48, insulin treatment was started [PG level at 120 min during OGTT at 46 yr (before treatment) was 1.5 times that at 34 yr]. Insulin secretion had also gradually decreased during the follow-up period (sum of IRI at 34 yr during OGTT post-treatment; 550.8 IU/ml, sum of IRI at 50 yr during OGTT post-treatment; 244.5 IU/ml). However, the insulinogenic indices were maintained at almost the same level value. Our results indicate that insufficient insulin secretion, which could not overcome insulin resistance, might play a crucial role in the pathophysiology and progression of diabetes in WS along with insulin resistance due to a post-receptor defect.

Significance of glutathione-dependent antioxidant system in diabetes-induced embryonic malformations

Hyperglycemia-induced embryonic malformations may be due to an increase in radical formation and depletion of intracellular glutathione (GSH) in embryonic tissues. In the past, we have investigated the role of the glutathione-dependent antioxidant system and GSH on diabetes-related embryonic malformations. Embryos from streptozotocin-induced diabetic rats on gestational day 11 showed a significantly higher frequency of embryonic malformations (neural lesions 21.5 vs. 2.8%, P<0.001; nonneural lesions 47.4 vs. 6.4%, P<0.001) and growth retardation than those of normal mothers. The formation of intracellular reactive oxygen species (ROS), estimated by flow cytometry, was increased in isolated embryonic cells of diabetic rats on gestational day 11. The concentration of intracellular GSH in embryonic tissues of diabetic pregnant rats on day 11 was significantly lower than that of normal rats. The activity of y-glutamylcysteine synthetase (gamma-GCS), the rate-limiting GSH synthesizing enzyme, in embryos of diabetic rats was significantly low, associated with reduced expression of gamma-GCS mRNA. Administration of buthionine sulfoxamine (BSO), a specific inhibitor of gamma-GCS, to diabetic rats during the period of maximal teratogenic susceptibility (days 6-11 of gestation) reduced GSH by 46.7% and increased the frequency of neural lesions (62.1 vs. 21.5%, P<0.01) and nonneural lesions (79.3 vs. 47.4%, P<0.01). Administration of GSH ester to diabetic rats restored GSH concentration in the embryos and reduced the formation of ROS, leading to normalization of neural lesions (1.9 vs. 21.5%) and improvement in nonneural lesions (26.7 vs. 47.4%) and growth retardation. Administration of insulin in another group of pregnant rats during the same period resulted in complete normalization of neural lesions (4.3 vs. 21.5%), nonneural lesions (4.3 vs. 47.4%), and growth retardation with the restoration of GSH contents. Our results indicate that GSH depletion and impaired responsiveness of GSH-synthesizing enzyme to oxidative stress during organogenesis may have important roles in the development of embryonic malformations in diabetes.

No deterioration in insulin sensitivity, but impairment of both pancreatic beta-cell function and glucose sensitivity, in Japanese women with former gestational diabetes mellitus

To identify the primary pathogenic factors involved in the development of Type 2 diabetes mellitus (DM), we studied Japanese women with former gestational diabetes mellitus (GDM) who are at risk for the later development of Type 2 DM. We used the minimal model analysis derived from frequently sampled intravenous glucose tolerance test (FSIGT). The subjects consisted of eight non-obese women with a history of GDM and eight non-obese normal women as control subjects. The 75 g oral glucose tolerance test (75 g OGTT) performed within 6 months of delivery confirmed that all the subjects with former GDM had a normal glucose tolerance. Insulin sensitivity (SI) derived from the minimal model analysis was not different between the two groups. Glucose effectiveness at zero insulin (GEZI), reflecting tissue glucose sensitivity, was significantly lower in former GDM patients than in control subjects (1.18+/-0.34 vs 2.26+/-0.29 x 10(-2) min(-1), p < 0.05). The early phase insulin secretion found in FSIGT was markedly reduced to 56% of that observed in control subjects (1250+/-87.4 vs 2223+/-304.3 pmol l(-1) min, p < 0.01). Our results indicate that in former GDM patients, who are japanese and non-obese, impairment of the acute insulin response to glucose and a decrease in tissue glucose sensitivity rather than insulin sensitivity are the primary pathogenic factors involved.

Expression of platelet-derived growth factor in lupus nephritis in MRL/MpJ-1pr/1pr mice

Platelet-derived growth factor (PDGF) plays an important role in the pathogenesis of mesangial proliferative glomerulonephritis. We examined PDGF expression and glomerular changes in lupus nephritis-prone MRL/MpJ-1pr/1pr (MRL/1) mice. The total number of nuclei per glomerular section and blood urea nitrogen (BUN) level were significantly increased in MRL/1 mice aged 20 weeks compared to those aged 8 weeks. A positive correlation existed between numbers of PDGF beta-chain-positive cells and glomerular cells in MRL/1 mice (r = 0.77, p < 0.01). The BUN level did not differ among MRL/MP-+2 (MRL/n) mice of different ages, but the glomerular cell number increased modestly with age. At the age of 20 weeks, the incidence of crescent formation per kidney tissue ranged from 9 to 32% (mean 19%) in MRL/1 mice but was 0 in MRL/n mice. PDGF beta-chain protein was expressed in the mesangium and crescents in 20-week-old MRL/1 mice but was expressed rarely in the glomeruli of MRL/n mice. These results suggest that the PDGF beta-chain plays an important role in glomerular cell proliferation and crescent formation in murine lupus nephritis.

Troglitazone ameliorates insulin resistance in patients with Werner's syndrome

Insulin resistance in Werner's syndrome (WS) is probably due to defective signaling distal to the insulin receptor. To analyze the metabolic effects of troglitazone (TRO) in these patients, we performed frequently sampled iv glucose tolerance tests. Glucose kinetics were analyzed by the minimal model. Five patients with WS (mean age, 41.2 yr; body mass index, 17.0 kg/m2) were treated with TRO (400 mg/day) for 4 weeks. Each subject underwent a 75-g OGTT and frequently sampled iv glucose tolerance tests. Treatment reduced the area under the curve of glucose and insulin in the OGTT by 26% and 43%, respectively. Glucose tolerance, as manifested by the glucose disappearance rate improved significantly (1.36 +/- 0.16 to 1.94 +/- 0.30%/min; P < 0.05). Although the first phase insulin secretion was unchanged, insulin sensitivity and glucose effectiveness increased significantly [0.47 +/- 0.11 to 1.38 +/- 0.37 x 10(-4) min/pmol.L (P < 0.05) and 1.72 +/- 0.17 to 2.52 +/- 0.24 x 10(-2) min-1 (P < 0.05), respectively]. However, treatment did not change glucose effectiveness at zero insulin. In patients with WS, TRO ameliorates glucose intolerance mediated by increased insulin sensitivity as well as glucose effectiveness, as assessed by minimal model analysis. TRO may modulate the postreceptor signaling component and be a clinically useful regimen for the treatment of patients with the intracellular insulin signaling defect.

Behcet's disease complicated with myelodysplastic syndrome: a report of two cases and review of the literature

Two cases of Behcet's disease associated with myelodysplastic syndrome are described. Both patients showed a chromosomal abnormality, trisomy 8. Based on the laboratory findings in our patients and a careful review of the literature of similar cases, the association of the chromosomal abnormality with the pathogenesis of Behcet's disease is suggested.

Effects of erythropoietin treatment on thyroid dysfunction in hemodialysis patients with renal anemia

The thyroid function was evaluated before and after 6 months of recombinant human erythropoietin (rhEPO) treatment (1,500-9,000 U/week) in 22 hemodialysis patients with hematocrit levels < 25%. Based upon the changes in hematocrit following rhEPO treatment, the patients were divided into two groups: 11 patients with an increase of the hematocrit level > 5% (group I) and 11 patients with an increase < 5% (group II). Before rhEPO administration, the levels of thyroid hormones, especially free thyroxine (T4) and free triiodothyronine (T3), were below the normal range despite normal thyrotropin values in most of the patients (low T4:7 cases in group I and 9 in group II; low T3:10 cases in group I and 10 in group II). RhEPO treatment significantly increased both total amount and free fractions of thyroid hormones in group I, whereas it did not affect these values in group II. Consequently, the pretreatment low T4 or low T3 status was resolved in a substantial number of the patients in group I (low T4:5 cases, low T3:4 cases). In addition, there was a significant correlation between the increases in hematocrit and free T3 in all studied subjects (r = 0.603; p < 0.05). These results suggest that anemia may participate to some extent in the pathogenesis of thyroid dysfunction in hemodialysis patients with renal anemia.

Glomerulosclerosis in the rat induced by repeated immune-mediated mesangial cell injury

Glomerulosclerosis is a common feature of progressive glomerular injury. We investigated whether experimental glomerulosclerosis could be induced by repeated immunologic injury to mesangial cells. Chronic mesangial proliferative glomerulonephritis (GN) was induced by repeated injections of polyclonal antibody directed against the Thy 1 antigen present on the mesangial cell membrane. An intravenous injection of anti-Thy 1 serum (ATS) was given weekly to 18 male Wistar rats, which were sacrificed at weeks 2, 4 and 6 after induction of GN. Blood urea nitrogen and serum creatinine were significantly elevated in rats with anti-Thy 1 nephritis at weeks 4 and 6 compared to normal rats. Progressive expansion of the mesangial matrix with diffuse sclerosis was observed at weeks 4 and 6 by silver methenamine staining. Ultrastructurally there was a prominent rough endoplasmic reticulum in the mesangial cells and collagenous fibrils in an expanded mesangial matrix. Immunohistochemical staining revealed a marked increase in type IV collagen and laminin in the mesangium at weeks 4 and 6. Thus, repeated immunologic injury restricted to the mesangium may result in the accumulation of extracellular matrix and the development of glomerulosclerosis. These studies emphasize the importance of the mesangial cell in progressive glomerular injury.

Effect of a novel immunosuppressant, FK506, on spontaneous lupus nephritis in MRL/MpJ-lpr/lpr mice

We evaluated the effect of the novel immunosuppressive agent, FK506, which is known to inhibit T cell immunity, on the development of lupus nephritis in MRL/MpJ-lpr/lpr (MRL/l) mice. FK506 was administered subcutaneously (1 mg/kg body weight) from 12 to 20 weeks of age in 13 MRL/l mice with spontaneous lupus nephritis. Nine animals receiving no treatment were used as the control. FK506 significantly reduced the development of proteinuria, lowered the level of BUN, and suppressed the elevation of serum anti-dsDNA antibodies. Histopathological study showed that FK506 significantly inhibited the progression of glomerular hypercellularity and crescent formation. Glomerular deposition of C3 was significantly reduced in the FK506-treated mice compared to the nontreated controls. These findings suggest that FK506 may protect against progression of lupus nephritis in MRL/l mice, an animal model of systemic lupus erythematosus.

Total and regional bone mineral density by dual photon absorptiometry in patients on maintenance hemodialysis

To evaluate bone loss in renal osteodystrophy, we measured total and regional (head, trunk, pelvis, leg and arm) bone mineral density (BMD) by dual photon absorptiometry in 72 patients on maintenance hemodialysis (HD). We also examined the validity of serum carboxy-terminal parathyroid hormone (C-PTH) and intact-PTH as an indicator of secondary hyperparathyroidism. Total BMD correlated inversely with age in female patients (r = -0.57, p less than 0.01), but not in male patients. Female patients older than 50 years were omitted from analysis to exclude the effect of menopause on bone. Among clinical and biochemical parameters, only trunk BMD correlated inversely with the duration of HD (r = -0.26, p less than 0.05). Head, trunk and total BMD correlated inversely with serum alkaline phosphatase, C-PTH and intact-PTH, while pelvis BMD did not. Leg and arm BMD also correlated inversely with serum intact-PTH, but not with serum C-PTH. The serum level of C-PTH correlated positively with the duration of HD (r = 0.40, p less than 0.005), while intact-PTH did not. As compared with 18 control male volunteers aged 25-42 years, trunk, pelvis, leg, arm and total BMD were significantly lower in male patients on HD aged 22-49 years, whereas head BMD did not differ significantly between the two groups. The percent decrease of BMD was most prominent in the trunk (-19.6%, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of the platelet-activating factor antagonists CV-6209 and CV-3988 on nephrotoxic serum nephritis in the rat

Platelet-activating factor (PAF) is known as an important mediator in the pathogenesis of glomerular injury. In the present study, we evaluated the effect of the specific PAF antagonists CV-6209 and CV-3988 on accelerated nephrotoxic serum nephritis (NTN) in the rat. The amount of urinary protein excretion was significantly less in the rats treated with CV-6209 or CV-3988 on the 5th and 7th day of treatment than in the nontreated controls. The results of light- and immunofluorescence-microscopic examination did not demonstrate any favorable effect on glomerular changes by these PAF antagonists. However, CV-6209 protected against the loss of glomerular anionic charges in rats with NTN. Thus, it is suggested that PAF is a potent mediator of protein excretion, and that the loss of glomerular anionic charges is an important mechanism for the mediation of PAF in glomerulonephritis.

Effect of the immunosuppressive agent, ciclosporin, on experimental immune complex glomerulonephritis in rats

Effect of the immunosuppressive agent, ciclosporin (CS), on bovine serum albumin (BSA) nephritis in rats was evaluated. Eight weeks after immunization, 19 male Wistar rats received a daily intravenous dose of BSA (2 mg). Two weeks later, 11 rats received BSA and an oral dose of CS (10 mg/kg), and 8 rats received only BSA for 2 weeks. Urinary protein was measured weekly and serum anti-BSA antibody was measured by passive hemagglutination biweekly. The animals were killed at the 12th experimental week and blood samples and kidney specimens were obtained. BUN and serum creatinine were measured at the time of sacrifice. Kidney specimens were processed for light and immunofluorescent microscopic examination. Urinary protein excretion was significantly less in CS-treated rats than in nontreated controls at the 2nd week after treatment (5.3 +/- 1.3 vs. 25.6 +/- 10.3 mg/day, p less than 0.05). Anti-BSA antibody titers were lower in treated rats than in controls at the 2nd week after the treatment. There were no significant differences in the levels of BUN and serum creatinine between two groups. Glomerular hypercellularity and mesangial widening were milder in treated rats than in controls, and glomerular deposition of BSA was less intense in treated rats than in controls. These results suggest that CS suppressed the antibody production and the development of glomerular changes in rats with immune complex glomerulonephritis.

IgA nephropathy and hepatitis B virus. IgA nephropathy unrelated to hepatitis B surface antigenemia

The incidence and pathogenetic role of hepatitis B surface antigen (HBsAg) were evaluated in patients with IgA nephropathy. Among 130 consecutive patients with IgA nephropathy, HBs antigenemia was detected in 4 patients (3.1%). Serum antibody to hepatitis B core antigen was positive in these 4 patients indicating that they were persistent carriers of hepatitis B virus. Serum hepatitis B e antigen (HBeAg) was detected in 1 patient, and antibody to HBeAg was positive in the other 3 patients. The incidence of HBs antigenemia was not significantly higher than the 2.0% of the general population. An immunofluorescent study in the renal tissues from the 4 IgA-nephritic patients with HBs antigenemia did not demonstrate HBsAg or HBeAg in the glomeruli. These findings suggest that HBsAg appears to play no role in the pathogenesis of IgA nephropathy.

Depressed natural killer cell activity in uremia. Evidence for immunosuppressive factor in uremic sera

We investigated the natural killer (NK) cell activity of peripheral blood mononuclear cells (PBMC) and the suppressive factor of NK cell activity in patients on maintenance hemodialysis (HD). NK cell activity was significantly lower in patients on HD than in healthy controls (20.2 +/- 16.5 vs. 31.0 +/- 13.2%, p less than 0.01). There was no difference in NK cell activity between patients treated with cuprophane and high-permeability membrane. NK cells from patients on HD showed a poor response to interleukin-2, and uremic sera significantly suppressed NK cell activity of normal PBMC. Although urea, creatinine, methylguanidine or guanidinosuccinic acid alone did not suppress the NK cell activity of normal PBMC, the guanidino compound did so significantly. It is suggested that defective NK cell activity in uremic patients explains in part their susceptibility to malignancy and infection. The immunosuppressive effect may be exhibited by synergism or mosaic of uremic toxins.

Hepatic calcification in the course of hemodialysis

Hepatocellular calcification is extremely rare and only one case has been recorded in the literature. The patient, a 74-yr-old Japanese woman, received hemodialysis for 5 months because of uremia due to chronic glomerulonephritis. Four months before death, she was once in a state of shock which lasted for 4 h due to massive hemorrhage from the shunt vein for hemodialysis. She died of disseminated intravascular coagulopathy and respiratory failure due to uremia. Postmortem liver biopsy showed centri- and midzonal necrosis associated with septal fibrosis where intracellular and extracellular calcification were noted. The calcifications were round or rod shaped and single or multiple in distribution. The calcification was thought to occur as the result of shock, which caused hepatocellular damage, due to consumption of a high calcium-phosphorus product.

Effect of the antiplatelet agents ticlopidine and dipyridamole on nephrotoxic serum nephritis in rats

The effect of the antiplatelet agents, ticlopidine and dipyridamole, on nephrotoxic serum nephritis (NTN) was evaluated in rats. An accelerated form of NTN was induced with preimmunization of rabbit IgG 7 days before injection of rabbit antirat nephrotoxic serum. Twelve animals received a peroral dose of 20 mg of ticlopidine daily, and 12 animals received a peroral dose of 10 mg of dipyridamole twice daily for 7 days. It was shown that both ticlopidine and dipyridamole were able to significantly reduce urinary protein excretion. There was, however, no significant difference in glomerular changes between treated animals and nontreated controls. Ticlopidine and dipyridamole were found to suppress the development of proteinuria in accelerated NTN. Although the antiaggregative action of dipyridamole was relatively weak in vivo, dipyridamole was found to be rather effective on protein excretion in the present study. These results support the significant role of platelets in the development of proteinuria in glomerulonephritis, and it is suggested that dipyridamole may have an antiproteinuric effect other than inhibition of platelet aggregation.

Membranoproliferative glomerulonephritis associated with chronic hepatitis B in adults: pathogenetic role of HBsAg

Two adult cases of membranoproliferative glomerulonephritis (MPGN) associated with chronic hepatitis B were reported. Serum HBsAg, HBeAg and anti-HBc were positive. Glomerular changes were essentially the same in both patients and consistent with MPGN type III. Immunofluorescence microscopy revealed diffuse granular and lumpy deposits of IgG, IgA, IgM, C1q and C3 along glomerular capillary walls and in mesangial areas. Granular deposition of HBsAg was observed along capillary walls and in mesangial areas, and the staining patterns were similar to those of immunoglobulins and complements in both patients. Glomerular deposition of HBeAg, however, was negative in one case, and only slight and segmental in the other case. These findings suggest that HBsAg rather than HBeAg may play a role in the pathogenesis of MPGN associated with hepatitis B virus infection in adults.

Effect of probucol on hyperlipidemia in patients with nephrotic syndrome

We have evaluated the effect of the antihyperlipidemic agent probucol on hyperlipidemia in patients with nephrotic syndrome. Twelve patients with long-standing nephrotic syndrome received 500 mg of probucol daily for 12 weeks. Serum total cholesterol, triglyceride, HDL-cholesterol and LDL-cholesterol were significantly lowered with probucol treatment. There were no differences in urine protein, serum total protein, serum albumin and renal function before and after probucol treatment. No drug-related side effects were observed during our study. These results indicated that probucol was effective against hyperlipidemia and free from side effects in patients with persistent nephrotic syndrome. The use of probucol is therefore suggested to be advisable when antihyperlipidemic treatment is required in some subgroups of nephrotic syndrome.

Effect of the anticomplementary agent, K-76 monocarboxylic acid, on experimental immune complex glomerulonephritis in rats

We examined the effect of the anticomplementary agent K-76 monocarboxylic acid (K-76COOH), which is known to inhibit C5 activity, on immune complex glomerulonephritis in rats. Bovine serum albumin (BSA) nephritis was induced in rats by subcutaneous immunization and daily intravenous administration of BSA. K-76COOH (30 mg/kg) was administered intraperitoneally twice daily for 4 weeks. It was shown that K-76COOH would significantly reduce the development of proteinuria in the early stage of BSA nephritis, but it failed to suppress proteinuria in the late stage. There was no significant difference in glomerular changes between treated animals and non-treated controls. These findings suggest that C5, and the terminal complement components may play a significant role in protein excretion in the early stage of immune complex glomerulonephritis.

Effect of the antiplatelet agents ticlopidine and dipyridamole on experimental immune complex glomerulonephritis in rats

The effect of the antiplatelet agents ticlopidine and dipyridamole on immune complex glomerulonephritis in rats was evaluated. Bovine serum albumin (BSA) nephritis was induced in rats with subcutaneous immunization and intravenous dosage of BSA. Ticlopidine and dipyridamole were administered for 4 weeks before and for 7 days after onset of proteinuria. It was shown that both ticlopidine and dipyridamole could reduce the development of proteinuria when administered before the onset of proteinuria. Ticlopidine also reduced the amount of urinary protein after onset of proteinuria, and may thus be more effective against urinary protein excretion. When the antiplatelet agents were administered before onset of glomerulonephritis, blood urea nitrogen and serum creatinine levels were significantly lower, and glomerular hypercellularity and mesangial widening were milder in animals treated with ticlopidine than in controls. Glomerular deposition of BSA was less intense in treated animals than in nontreated controls. Thus, ticlopidine as well as dipyridamole was found to inhibit the development of proteinuria and glomerular alteration. It is suggested that ticlopidine could be more effective than dipyridamole against the development of immune complex glomerulonephritis in rats.

Glomerular deposition of IgA in experimental hepatic cirrhosis

Wistar rats rendered cirrhotic with carbon tetrachloride excreted significant proteinuria and hematuria. Serum levels of IgA and IgG were significantly elevated in cirrhotic animals. They showed mild mesangial proliferation and immunofluorescent studies revealed deposits of IgA and IgG predominantly in mesangial areas and along capillary walls. These findings were very similar to those seen in patients with hepatic cirrhosis or IgA nephropathy. The deposits of IgA were also found in hepatic tissue from cirrhotic animals. The intensity and distribution of glomerular IgA deposits were not diminished after treatment with acid buffer. These results suggest that glomerular IgA are IgA polymers and decreased hepatic clearance of hepatic IgA polymers may be responsible for the glomerular deposition of IgA.