Two adult cases of IgM-associated mesangial proliferative glomerulonephritis

Two adult patients with mesangial proliferative glomerulonephritis with diffuse IgM deposition in the glomeruli are reported. Case 1 was a 25-year-old female with nephrotic syndrome who showed complete remission after treatment with prednisolone (PSL). Case 2 was a 46-year-old male with asymptomatic proteinuria who showed incomplete remission (0.5-1.0 g/24 hr) of urinary protein without any medication. In light microscopy, these patients revealed minimal or slight proliferation of glomerular mesangial cells without glomerular sclerosis and crescent formation. Deposition of IgM and C3 was observed in the glomerular mesangial areas and capillary walls by immunofluorescence. Electron-dense deposits were observed in the glomerular mesangial areas in these patients. Mesangial proliferative glomerulonephritis associated with diffuse IgM deposition in the glomeruli appears to have a benign clinical course. It has also been suggested that this disease has variant clinical courses since we recently experienced two other patients with mesangial proliferative glomerulonephritis with focal IgM deposits who showed renal tubular dysfunction or chronic renal failure.

[Hypersensitivity angiitis, Henoch-Schönlein purpura]

Pathogenesis and treatment of hypersensitivity angiitis and Henoch-Schönlein purpura were summarized. Both diseases were included in the category of "leukocytoclastic vasculitis". Hypersensitivity angiitis was frequently associated with drug or infectious exposure and the involvement of venules and capillaries. Many patients with this disease have detectable autoantibodies to neutrophil cytoplasmic antigens (ANCA) typically reactive with myeloperoxidase. Henoch-Schönlein purpura was characterized by vasculitis in multiple organs such as the skin, joints, gastrointestinal tract and kidneys. Henoch-Schönlein purpura nephritis revealed marked deposition of IgA (mainly IgA1) and C3 in the glomerular mesangial areas and capillary walls by immunofluorescence. Combinations of intensive plasma exchange, steroids and cyclophosphamide were effective for patients with both diseases.

Latex agglutination test negative cryptococcal meningitis in an immuno-competent individual: a case report

We report a case with progressive mental deterioration and persistent low grade fever, who was diagnosed to have cryptococcal meningitis. This case is unique in that the cryptococcal latex agglutination antigen test was consecutively negative. The diagnosis was made by sequential CSF culture.

Low protein diet blunts the rise in glomerular gene expression in focal glomerulosclerosis

The present study was designed to assess whether expression of mRNA for extracellular matrix (ECM) components, metalloproteinases (MMP) and tissue inhibitor of metalloproteinases (TIMP) in glomeruli is affected by a low protein diet during the course of focal glomerulosclerosis (FGS). Puromycin aminonucleoside (PAN) was injected intraperitoneally in rats and the right kidney was removed on day 22. Nephrotic rats received successive intraperitoneal injections of PAN on days 27, 34, and 41. Control rats were subjected to a nephrectomy or a sham operation on day 22. Animals were divided into six groups. In group 1, the PAN-injected rats were fed a standard diet containing 22% protein. In group 2, the PAN-injected rats were fed a low protein diet containing 6% protein, starting on the same day as the first PAN injection. In group 3, the nephrectomized rats without PAN were fed a standard diet. In group 4, the nephrectomized rats without PAN were fed a low protein diet for the same period. In group 5, the sham operated rats were fed a standard diet. In group 6, the sham operated rats were fed a low protein diet for the same period. Rats were sacrificed on days 0, 60 or 80 after the initial PAN or saline injection. The percentage of sclerotic glomeruli in group 1 rats increased markedly with time, reaching 77% on day 80. The mRNA levels encoding for alpha 1(I), alpha 1(III), alpha 1(IV) collagen chains, laminin B1 and B2 chains, heparan sulfate proteoglycan (HSPG), MMP-2, TIMP-1 and TIMP-2 increased significantly as glomerulosclerosis progressed, whereas MMP-1 and MMP-3 mRNA levels were unchanged, and no MMP-9 mRNA was detected throughout the experiments. In group 2, the low protein diet reduced the prevalence of glomerulosclerosis and attenuated the increased mRNA expression for ECM components, MMP-2, TIMP-1 and TIMP-2 in FGS glomeruli. In groups 3 through 6, mRNA levels for ECM components decreased with age, whereas those for MMPs and TIMPs changed little throughout the experiments. Immunofluorescence studies revealed the accumulation of types I, III and IV collagens, laminin, and HSPG in the sclerotic area and low protein diet attenuated the accumulation of these proteins. These data suggest that glomerulosclerosis may result from an imbalance among ECM components, MMPs and TIMPs and that a low protein diet attenuates the otherwise increased levels of mRNA for ECM components, MMP-2, TIMP-1 and TIMP-2 in glomerulosclerosis.

Effects of enalapril on endothelin-1 and growth factor gene expression in diabetic rat glomeruli

We have previously reported that the mRNA levels of endothelin (ET-1), tumor necrosis factor-alpha), (TNF-alpha), platelet-derived growth factor (PDGF)-B chain, transforming growth factor (TGF-beta), and basic fibroblast growth factor (bFGF) all increased with age in diabetic rat glomeruli. We have now assessed the effect of the angiotensin-converting enzyme inhibitor enalapril on the expression of the ET-1, TNF-alpha, PDGF-B, TGF-beta, and bFGF genes in 24-week-old rat glomeruli after streptozotocin injection. Animals were divided into controls, enalapril-treated diabetic rats, and untreated diabetic rats. Treatment continued for 24 weeks. Enalapril reduced both creatinine clearance (p < 0.001) and urinary protein excretion (p < 0.01) in diabetic rats. Enalapril produced a nonsignificant 15 mm Hg reduction in blood pressure in diabetic rats. Enalapril also attenuated the increases in ET-1 mRNA levels observed in the glomeruli of diabetic rats (0.5-fold compared with untreated diabetic rats at 24 weeks [p < 0.01]) but had no effect on increased mRNA levels of TNF-alpha, PDGF-B, TGF-beta, and bFGF. These findings suggest that enalapril therapy may be effective in reducing ET-1 mRNA expression in the glomeruli of diabetic nephropathy.

Three-dimensional surface display of brain perfusion with 123I-IMP in Parkinson's disease

We reconstructed three-dimensional (3D) surface images from single-photon emission computed tomography (SPECT) data using N-isopropyl-p[123I]-iodoamphetamine (123I-IMP) in 27 patients with Parkinson's disease and 11 normal control subjects. The 3D reconstruction was performed using distance-shaded methods at threshold levels with an interval of 5% from 45-80%. Any area of decreased perfusion at each threshold level was visualised as a defect area by the algorithm. In nondemented patients with Parkinson's disease, perfusion defects were frequently found in the parietal cortex at a threshold value of 65%. In demented patients, perfusion defects were frequently seen at thresholds of 45-65%, and were more marked in the temporal and parietal cortex bilaterally. This suggests that dementia in Parkinson's disease is related to a reduction of perfusion in the temporoparietal cortex.

[Three-dimensional surface display with 123I-IMP brain perfusion imaging in patients with dementia]

We reconstructed three-dimensional (3D) surface images from single photon emission computed tomography (SPECT) data with N-isopropyl-p [123I]-iodo-amphetamine (123I-IMP) in 27 patients with Parkinson's disease, 16 patients with Alzheimer's disease, 9 patients with Binswanger's disease, and 11 elderly normal subjects. Three-D reconstruction was performed with Starcam 3000 XC/T using distance-shaded method at the threshold levels at intervals of 5% from 45% to 80%. In normal control subjects, no perfusion defects were found in any region at threshold values below 60%, although the frontal and temporal cortices occasionally showed perfusion defects at threshold levels from 60% to 80%. In patients with Parkinson's disease with dementia, perfusion defects were diffuse, particularly in the parietal and temporal cortices even at a threshold of 45%. Patients with Alzheimer's disease also showed diffuse perfusion defects, particularly in parietal and temporal cortices even at threshold levels as low as 45%. The primary visual cortex was less affected in these patients. The demented Parkinson's disease patients demonstrated perfusion defects similar to those of patients with Alzheimer's disease, although perfusion defects were more prominent in patients with Alzheimer's disease. In patients with Binswanger's disease, patchy perfusion defects were found most frequently in the frontal region. In addition, perfusion defects in the cerebellum and sensory motor cortex were more frequent in the Binswanger's disease patients than in patients with Alzheimer's or Parkinson's disease and normal subjects. The demented Parkinson's disease patients showed perfusion defects in the temporal and parietal cortices and demonstrated a perfusion pattern similar to that of patients with Alzheimer's disease.(ABSTRACT TRUNCATED AT 250 WORDS)

A case of thin basement membrane syndrome associated with idiopathic membranous nephropathy

A 59-year-old woman has had persistent microscopic hematuria for 10 years. A few days after the onset of upper respiratory tract infection, edema and severe proteinuria appeared. In renal biopsy, an electron micrograph revealed electron dense deposits in the subepithelial regions with diffuse thinning of the glomerular basement membrane. These glomerular findings were compatible with thin basement membrane syndrome associated with membranous nephropathy. On the basis of our review of the literature, the association of these two diseases seems to be very rare.

Detection of glycosylated protein in glomeruli of STZ-induced diabetic rats using the nitroblue tetrazolium (NBT) reaction

Detection of glycosylated protein in renal tissues was determined in streptozotocin (STZ)-induced diabetic rats using the nitroblue tetrazolium (NBT) reaction. The glycosylation of extra-cellular matrix (ECM) components such as laminin and fibronectin was examined in vitro using the same method. Immunofluorescence staining of laminin or type IV collagen was also performed in renal tissues of STZ-induced diabetic rats. There was no significant difference in the intensity of NBT in renal tissues between 4 week STZ-induced diabetic rats and control rats of the same age. The intensity of NBT staining in the glomerular mesangial areas and capillary walls was marked in 12 week diabetic rats. The mean values of fructosamine measured by the NBT reaction in the glycosylated-laminin and fibronectin were increased dose dependently. In immunofluorescence, laminin and type IV collagen were observed significantly in the glomerular mesangial areas and capillary walls of 12 week diabetic rats. However, there was no significant change in renal histopathology in 4 and 12 weeks diabetic rats. It appears that the non-enzymatic glycosylation and expression of ECM components in glomeruli increased in the early stage of diabetic nephropathy prior to the appearance of marked histologic alterations. In conclusion, non-enzymatic glycosylation of glomerular structural components may play an important role in the initiation of the early stage of renal injuries in diabetes.

IgA deposits might not influence the production of extracellular matrix in glomeruli of ddY mice, a spontaneous animal model for IgA nephropathy

Immunofluorescence studies were carried out to determine whether the expression of extracellular matrix (ECM) in glomeruli of ddY mice, a model for IgA nephropathy (Berger's disease), is influenced by treatment with a rat monoclonal antibody to murine CD4 molecules (mAb CD4). This mAb CD4 showed a selective decrease in the number of CD4+ T cells in the peripheral blood of ddY mice as described previously. The ddY mice were initially treated with intravenous injections, followed by weekly intraperitoneal injections of mAb CD4. In immunofluorescence, the mean intensity of IgA deposits in the renal glomerular mesangial areas and capillary walls of the treated ddY mice was significantly lower than that in saline-treated control mice at comparable ages. There was no significant difference in the distribution or intensity of ECM components, i.e. type IV collagen, fibronectin and heparan sulfate proteoglycan, in glomeruli between the mAB CD4-treated and the control ddY mice. In light microscopy, mesangial expansion in the treated ddY mice was milder than that found in the saline control mice. No significant differences in the average number of intraglomerular cells, levels of serum IgA and urinary protein between the treated and control ddY mice were observed. Thus, it appears that although CD4+ T cells modulate the amounts of glomerular IgA deposits, other factors may be involved in the expression of ECM in glomeruli of IgA nephropathy in ddY mice.

Effect of monoclonal antibody CD4 on expression of intercellular adhesion molecule 1 in renal tissues of ddY mice: a spontaneous animal model of IgA nephropathy

Immunofluorescence studies were performed to determine whether the expression of intercellular adhesion molecule 1 (ICAM-1) in ddY mice, a model for IgA nephropathy (Berger's disease), is influenced by treatment with a rat monoclonal antibody to murine CD4 molecules. The ddY mice were initially treated with intravenous injections, followed by weekly intraperitoneal injections of monoclonal antibody CD4. Using immunofluorescence, the mean intensity of IgA deposits in renal glomerular mesangial areas and capillary walls of the treated ddY mice was significantly lower than that in saline-treated control ddY mice of comparable ages. Marked expression of ICAM-1 was observed in glomerular capillary walls and mesangial areas in both control and treated ddY mice aged 40 and 70 weeks. The glomerular mesangial expansion in the treated ddY mice was milder than that found in the control ddY mice. No significant difference in glomerular cell proliferation between the treated and control ddY mice was observed. Although the infiltration of CD4+ T cells in glomeruli was slightly decreased after the treatment, that of CD8+ T cells and macrophages/monocytes was marked in both control and treated ddY mice aged 40 and 70 weeks. Thus, it appears that CD4+ T cells modulate the amount of IgA deposits in glomeruli, and other factors may be involved in the expression of ICAM-1 in glomeruli of IgA nephropathy in ddY mice.

Detection of glycosylated protein in renal tissues and dermal vascular vessels in the microalbuminuric stage of diabetic nephropathy using the nitro blue tetrazolium reaction

Detection of glycosylated protein in renal and dermal tissues was performed in patients in the microalbuminuric stage of diabetic nephropathy using the nitro blue tetrazolium (NBT) reaction. The intensity of NBT staining in glomeruli and dermal vascular vessels was marked in the microalbuminuric stage as well as in the overtly proteinuric stage. The NBT staining in the renal and dermal vascular walls in both stages was significantly stronger than in the samples of control autopsy patients. It appeared that nonenzymatic glycosylation in various tissues, i.e. kidneys and dermal vascular vessels, had already progressed in the microalbuminuric stage in patients with diabetic nephropathy.

Expression of intercellular adhesion molecule-1 and infiltration of lymphocytes in glomeruli of patients with IgA nephropathy

Using immunofluorescence, we studied 19 patients with IgA nephropathy to determine whether the expression of intercellular adhesion molecule (ICAM)-1 in glomeruli might reflect the disease activity. The relationship between the expression of ICAM-1 and the infiltration of lymphocytes, monocytes and polymorphonuclear leukocytes (PMN) in glomeruli of IgA nephropathy cases was examined. The expression of ICAM-1 in patients in the advanced stage was significantly higher than that in patients in the mild stage. In double immunofluorescence, the distribution of ICAM-1 expression in glomeruli was different from that of IgA deposition in patients in both stages. Glomeruli which showed increases of ICAM-1 expression had marked infiltration of lymphocytes (OKT4+, OKT8+ T cells), and monocytes (OKM1+ cells). Increase of urinary protein and decreases in renal function were observed in patients in the advanced stage. It appears that the expression of ICAM-1 is closely linked to glomerular cell proliferation, and infiltration of lymphocytes and monocytes in patients with IgA nephropathy. However, the expression of ICAM-1 in glomeruli might not be correlated with IgA-dominant immune complexes in this disease.

Endothelin-1 mRNA expression by peripheral blood monocytes in IgA nephropathy

We investigated endothelin-1 mRNA expression in peripheral blood monocytes from 40 patients with IgA nephropathy, 40 with other glomerulonephritides and 10 with essential hypertension without renal diseases, and from 30 healthy age-matched controls. 95% of patients with IgA nephropathy had increased endothelin-1 mRNA expression in monocytes but little was detected from the other groups. Endothelin-1 mRNA was positively correlated with urinary protein excretion (95% CI 0.835-0.952) and histopathological findings (0.796-0.939). In 15 patients with IgA nephropathy endothelin-1 mRNA values and proteinuria decreased gradually after treatment. Endothelin-1 mRNA-expressing activated monocytes may be associated with the progression of IgA nephropathy.

A case of nephrotic syndrome associated with hepatic glomerulosclerosis and diabetic nephropathy

We report here an adult case of nephrotic syndrome associated with hepatic glomerulosclerosis with the hepatitis C virus (HCV) antigen and diabetic nephropathy. To clarify the etiology of the nephrotic syndrome, we performed a renal biopsy and obtained the histological findings of hepatic glomerulosclerosis, glomerular mesangial cell proliferation and mesangial expansion. Electron dense deposits and deposits of IgA and C3 were also noted in the glomerular mesangial areas. Histological findings of diabetic nephropathy included thickening of the glomerular basement membrane and aneurysmal change of glomerular capillary walls in light microscopy. In immunofluorescence, linear staining of IgG was observed in the glomerular capillary walls, Bowman's capsules and tubular basement membranes. HCV was also detected focally in the glomerular capillary walls by immunofluorescence. Association of these two diseases has not been reported in any of the previous manuscripts that we reviewed. Thus, this patient seems to be a case of very rare association of the two diseases.

Brain perfusion imaging in Parkinson's disease and Alzheimer's disease demonstrated by three-dimensional surface display with 123I-iodoamphetamine

We reconstructed three-dimensional (3D) surface images from data from single-photon emission computed tomography (SPECT) with N-isopropyl-p[123I]-iodoamphetamine (123I-IMP) in 29 patients with Parkinson's disease, 16 patients with Alzheimer's disease and 11 normal control subjects. In patients with nondementing Parkinson's disease, perfusion defects were frequently found in the parietal cortical region at a threshold value of 65%. In demented Parkinson's disease patients, perfusion defects were frequently noted at threshold of 45-65%, and were more marked in the bilateral temporal and parietal cortices. In Alzheimer's disease, perfusion defects were similar to those found in dementing Parkinson's disease. These results suggest that dementia in Parkinson's disease is related to the perfusion reduction of the temporoparietal cortex, and may support the view that Parkinson's disease and Alzheimer's disease overlap in some patients. A 3D display of an 123I-IMP brain tomogram may be useful for detecting cortical lesions in patients with dementia or cognitive impairment.

Increased endothelin and endothelin receptor mRNA expression in polycystic kidneys of cpk mice

The renal mRNA levels of endothelin (ET)-1 and ET-3 and for ET receptors A and B were measured in the cystic kidneys of cpk/cpk mice at 1, 2, and 3 wk of age. At 1 wk of age, renal ET-1 mRNA was 3.2-fold greater in cystic mice than in controls and continued to increase with the progression of cyst formation to reach 10.4-fold more than controls at 3 wk. ET-3 mRNA levels did not differ between cystic and control mice. Renal ETA and ETB receptor mRNA increased gradually in cystic mice with the progression of their cysts, reaching 4.2- and 6.3-fold increases over controls, respectively, at 3 wk. Proliferating cell nuclear antigen mRNA expression was also examined, and proliferating cell nuclear antigen mRNA levels were found to be significantly increased in the kidneys of cystic mice compared with controls: 2. 1-fold at 1 wk, 4.5-fold at 2 wk, and 7.8-fold at 3 wk. The mRNA levels for transforming growth factor beta (TGF-beta) and tumor necrosis factor alpha (TNF-alpha) in the kidneys of cystic mice were also examined and were found to be increased progressively with age (TGF-beta, 2.1-fold at 1 wk, 4.2-fold at 2 wk, and 6.2-fold at 3 wk; TNF-alpha, 2.2-fold at 1 wk, 3.8-fold at 2 wk, and 5.4-fold at 3 wk).(ABSTRACT TRUNCATED AT 250 WORDS)

Renal expression of mRNAs for endothelin-1, endothelin-3 and endothelin receptors in NZB/W F1 mice

Endothelin (ET)-1, ET-3, and ET receptors are widely distributed in the vascular system and the kidney. The present study was designed to measure the renal concentrations of ET-1, ET-3, and ET receptor mRNAs in NZB/W F1 mice at 8, 24, and 48 weeks of age. The renal concentration of ET-1 mRNA increased significantly in NZB/W F1 mice as their nephritis progressed, reaching, by 48 weeks, a 10-fold higher concentration than in control NZW mice. Renal ET-3 mRNA concentrations, however, remained unchanged. The renal concentrations of ET receptor A and B mRNAs in NZB/W F1 mice increased gradually with the progression of nephritis, reaching 5- and 3-fold higher concentrations, respectively, at 48 weeks of age than found in control mice. Transforming growth factor-beta (TGF-beta) and tumor necrosis factor-alpha (TNF-alpha) have been shown to stimulate ET-1 mRNA expression in cultured mesangial cells. We therefore also examined the concentrations of TGF-beta and TNF-alpha mRNAs in the renal tissues of NZB/W F1 mice, and found that, at 48 weeks of age, they were 10- and 8-fold higher, respectively, than in control NZW mice. At 24 weeks, NZB/W F1 mice were divided into two groups receiving either methylprednisolone (MPSL) or saline injections for the following 24 weeks. The development of the histologic lesions characteristic of lupus nephritis and the increased renal concentrations of ET-1, ET receptors, TGF-beta and TNF-alpha mRNAs were suppressed by MPSL treatment. These data suggest that ET and ET receptor gene transcription is upregulated in the renal tissues of NZB/W F1 mice and that the beneficial treatment of lupus nephritis with MPSL is accompanied by a reduction in the elevated concentrations of ET-1, ET receptors, TGF-beta and TNF-alpha mRNAs.

Gene expression of metalloproteinases and their inhibitor in renal tissue of New Zealand black/white F1 mice

1. The present study was carried out to determine how levels of the mRNA of metalloproteinases (metalloproteinase-1, 72 kDa type IV collagenase, metalloproteinase-3 and 92 kDa type IV collagenase) and tissue inhibitor of metalloproteinases are regulated in the renal tissues of New Zealand Black/White F1 mice. 2. mRNA levels for metalloproteinase-1, 72 kDa type IV collagenase, metalloproteinase-3 and tissue inhibitor of metalloproteinases increased significantly with the progression of nephritis in New Zealand Black/White F1 mice. 3. At 48 weeks of age, the levels of mRNA for metalloproteinase-1, 72 kDa type IV collagenase, metalloproteinase-3 and tissue inhibitor of metalloproteinases increased by 8-, 4-, 8- and 15-fold, respectively, in the renal tissues of New Zealand Black/White F1 mice compared with New Zealand White mice. 4. In the kidneys of New Zealand White mice, however, the mRNA levels of these proteins changed little throughout the experimental period. 5. We could not detect expression of mRNA for 9 2 kDa type IV collagenase in the renal tissue of New Zealand Black/White F1 mice at 8 weeks of age or in New Zealand White mice at 8, 24 or 48 weeks of age, whereas we could detect expression of mRNA for this protein in New Zealand Black/White F1 mice at 24 and 48 weeks of age when mononuclear cells had infiltrated the interstitium and surrounding blood vessels. 6. At 24 weeks of age, New Zealand Black/White F1 mice were divided into two groups and received either methylprednisolone or saline injection for 24 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunofluorescent analysis of extracellular matrix (ECM) components in glomeruli of the hepatic glomerulosclerosis

An immunofluorescence study was carried out to evaluate alterations in the distribution and/or intensity of extracellular matrix (ECM) components, immunoglobulins and complement (C3) in the glomeruli of 7 autopsy patients with hepatic glomerulosclerosis. As compared with the findings in normal renal tissues, an increase in type IV collagen, laminin and fibronectin was observed in expanded glomerular mesangial areas and along glomerular capillary walls. Depositions of IgA, mainly IgA1, and C3 in glomeruli were in parallel with those of the ECM components. These ECM components were markedly decreased in glomeruli showing global sclerosis. In contrast, type I collagen was observed at central portions of the sclerotic glomeruli. There was an increase in the type I collagen along Bowman's capsules, especially at the sites of capsular adhesion and crescent formation. It appears that hyperproduction and/or infiltration of glomerular ECM components and interstitial collagen is closely linked to the progression of glomerular sclerosis in patients with liver diseases.

Gene expression for endothelins and their receptors in glomeruli of diabetic rats

The present study was designed to assess levels of messenger RNA encoding for endothelin-1, endothelin-3, and endothelin receptors A and B in glomeruli of rats with streptozotocin-induced diabetes at 4, 12, and 24 weeks of age. In addition, streptozotocin-induced rats with diabetes were either treated with 8 to 14 units neutral protamine Hagedorn insulin daily to maintain moderate hyperglycemia (approximately 200 mg/dl) or left untreated to produce severe hyperglycemia (more than 400 mg/dl) during the 4-week study period. The messenger RNA levels for endothelin-1 in glomeruli of diabetic rats increased with the progression of diabetic nephropathy (4 weeks, 2.5 times control level, p < 0.01; 12 weeks, 3.8 times, p < 0.01; and 24 weeks, 5.3 times, p < 0.001. In contrast, messenger RNA levels for endothelin receptors A and B were not altered in glomeruli from diabetic and control rats throughout the experimental period. Messenger RNA for endothelin-3 in glomeruli from diabetic and control rats was not detected until 24 weeks of age. Insulin treatment partially ameliorated the increase in messenger RNA for endothelin-1 in the glomeruli of diabetic rats (0.3 times compared with diabetic rats without insulin treatment, p < 0.01), whereas insulin treatment did not affect messenger RNA for endothelin receptors A and B in diabetic glomeruli. These findings indicate that increased endothelin-1 messenger RNA in glomeruli may be a manifestation of diabetic nephropathy, and hyperglycemia or insulin-deficiency may play a role in abnormal endothelin-1 gene regulation.