Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.3.1.109 (AST)
 6,066 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to examine the mechanism by which the oral carbonaceous adsorbent, AST-120 delays the appearance of glomerular sclerosis, experiments were carried out in 120 male Sprague-Dawley rats weighing 285-320 g. The rats were first subjected to 2/3, 3/4, and 4/5 nephrectomy (n = 40). The experiments were begun at 2 weeks after the surgery, and were performed over an 8-week period. Half of each group (n = 20) was administered 1 g/day of liquid AST-120, and the other half received liquid vehicle solution with pair feeding in each group. In the 2/3 nephrectomized group the administration of AST-120 delayed the occurrence of glomerular hypertrophy and prevented the appearance of glomerular sclerosis without any significant differences in renal function, systemic blood pressure (SBP), and urinary protein excretion (U-P). In the 3/4 nephrectomized group the administration of AST-120 delayed the appearance of glomerular hypertrophy and sclerosis with significant decreases in SBP and U-P. In the 4/5 nephrectomized group the administration of AST-120 delayed the appearance of glomerular sclerosis and prevented a decrease in renal function. It is concluded that administration of the oral adsorbent AST-120 delays the occurrence of glomerular sclerosis by delaying the appearance of glomerular hypertrophy, systemic hypertension, and the increase in proteinuria. It can be therefore mentioned that the accumulating substances in the digestive tract worsen the abnormal milieu of chronic renal failure.
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PMID:Correction by oral adsorbent of abnormal digestive tract milieu in rats with chronic renal failure. 756 81

To elucidate the mechanisms by which factors in the digestive tract influence the progressive chronic renal failure in rats, we employed the oral adsorbent, AST-120, which can adsorb certain uremic toxins in the gastrointestinal fluid. Administration of AST-120 firstly delayed the appearance of systemic hypertension, secondly delayed the increase in the amount of urinary protein excretion, and finally delayed the emergence of glomerular hypertrophy and glomerulosclerosis. The data obtained did not provide evidence for an inhibitory effect of AST-120 on hypertension. Our results therefore suggest that a pressor substance or its precursor exists in the digestive tract of rats with chronic renal failure.
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PMID:Influence of factors in the digestive tract on the progression of chronic renal failure. 833 93

In order to examine the initiation time of drug treatment for chronic renal failure by the removal of certain substances which are accumulated in the digestive tract, experiments were carried out on 60 male Sprague-Dawley rats weighing 285-325g. The rats were first subjected to 2/3, 3/4 and 4/5 nephrectomy (n = 20). The experiments were begun at 2 weeks after the surgery, and were performed over an 8-week period. Half of each group of nephrectomized rats (n = 10) was administered the oral adsorbent, 1 g/day of Kremezin (AST-120, Kureha Chemical Industry Co, Tokyo), and pair feeding was done in each group of nephrectomized rats. The administration of Kremezin delayed the occurrence of glomerular hypertrophy, glomerulosclerosis, hypertrophy of the glomerular epithelial cells, flattening of the tubular cells, dilation of the tubular cavity and infiltration of monocytes into the interstitium in the 2/3 nephrectomized rats. In addition, the administration of Kremezin delayed the appearance of proteinaceous cast formation in the tubules, ballooning of the tubular cells, an increase in systemic blood pressure and an increase in urinary protein excretion in the 3/4 and 4/5 nephrectomized rats. These findings indicated that the correction of an abnormal milieu within the digestive tract in chronic renal failure can delay its progression. Since the level of the creatinine clearance in the 2/3 nephrectomized rats was equal to approximately 60% of the creatinine clearance in normal rats, it is suggested that drug treatment for chronic renal failure with Kremezin should be initiated before the level of the creatinine clearance decreases to 60% of creatinine clearance in normal human.
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PMID:[Study on the initiation time of drug treatment for chronic renal failure]. 837 90

We have recently demonstrated that indoxyl sulfate promotes the progression of glomerular sclerosis in uremic rats. In the present study, we determined whether an oral adsorbent (AST-120) could reduce the serum and urine levels of indoxyl sulfate and suppress the progression of chronic renal failure (CRF) in undialyzed uremic patients. Twenty-five undialyzed uremic patients were given AST-120 at a dose of 6 g/day for 6 months, while 10 undialyzed uremic patients were not given AST-120. The effects of the oral adsorbent on the slope of the 1/serum creatinine (Scr)-time plot, and the serum and urine levels of indoxyl sulfate were evaluated. Administration of AST-120 significantly decreased the serum and urine levels of indoxyl sulfate, and tended to improve the slope of the 1/SCr-time plot in the CRF patients. Among the patients in whom urinary excretion of indoxyl sulfate was reduced by AST-120, the oral adsorbent significantly improved the slope of the 1/SCr-time plot. The change in the slope of the 1/SCr-time plot showed a significant negative correlation with the change in the urine level of indoxyl sulfate. Thus, patients who showed a greater decrease of urinary indoxyl sulfate also showed more marked suppression of the progression of CRF. These results support the notion that indoxyl sulfate, a protein metabolite, is involved in the progression of CRF, and that an oral adsorbent can delay progression at least partly by reducing the serum and urine levels of indoxyl sulfate.
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PMID:The protein metabolite hypothesis, a model for the progression of renal failure: an oral adsorbent lowers indoxyl sulfate levels in undialyzed uremic patients. 935 Jun 73

This prospective, randomized controlled study was designed to examine the effects of oral adsorbent AST-120 on the progression of chronic renal failure (CRF) in patients on a strict low protein diet (LPD). Twenty-six patients with CRF (serum creatinine 3.0 to 8.6 mg/dl) on a LPD were randomly assigned to a control group (N = 13) or an AST-120 group (N = 13). The 1/Cr slope and creatinine clearance (CCr) slope were used to estimate the progression rate of CRF; uremic toxins, serum and urinary indoxyl sulfate (IS), peak 2a and guanidino substrates (GS) measured by HPLC. Comparisons were made between the baseline observation period for 6 to 12 months and the treatment period (0.6 g/kg/day of LPD alone or concurrent with 6 g/day of AST-120, for the control and the AST-120 groups, respectively) for 12 to 24 months in both groups. Both the 1/Cr slope and CCr slope were significantly lessened in the treatment period only in the AST-120 group. Serum and urinary IS, but neither peak 2a nor GS were significantly decreased in the treatment period only in the AST-120 group. We conclude that AST-120 administration concurrent with LPD may be superior to LPD alone in retarding the progression of CRF by inhibiting accumulation of indoxyl sulfate.
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PMID:Effects of oral adsorbent AST-120 on the progression of chronic renal failure: a randomized controlled study. 940 55

We recently demonstrated that indoxyl sulfate is a stimulating factor for the progression of chronic renal failure (CRF). In this study we determined whether the urine or serum levels of indoxyl sulfate are related to the progression rate of CRF in undialyzed uremic patients. Fifty-five CRF patients with a serum creatinine of >2 mg/dl who had not been treated with an oral sorbent (AST-120) were randomly enrolled in the study. We measured the serum and urine levels of indoxyl sulfate, and estimated the recent progression rate of CRF as the slope of the reciprocal serum creatinine versus time (1/S-Cr-time) plot. The mean urinary amount of indoxyl sulfate in the patients was 60 mg/day. Those with indoxyl sulfate urine levels of >60 mg/day had a significantly faster progression rate of CRF than those with <60 mg/day. Especially, those patients with indoxyl sulfate urine levels of >90 mg/day had the highest CRF progression rate and those with indoxyl sulfate urine levels of <30 mg/day had the slowest CRF progression rate. Urinary indoxyl sulfate had a significantly negative correlation with the slope of the 1/S-Cr-time plot. However, the serum level of indoxyl sulfate or the ratio of serum indoxyl sulfate to creatinine was not significantly correlated with the slope of the 1/S-Cr-time plot. In conclusion, high urine levels of indoxyl sulfate are related with a rapid progression of CRF in undialyzed uremic patients. Thus, urinary indoxyl sulfate is one of the clinical factors that affect CRF progression.
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PMID:Urinary indoxyl sulfate is a clinical factor that affects the progression of renal failure. 1020 73

Circulating uremic substances are thought to be involved in the progression of chronic renal failure (CRF). An oral adsorbent AST-120 (Kremezin) is effective in removing circulating uremic toxins from the gastrointestinal tract, and retards the progression of CRF. AST-120 is widely used as an approved drug in Japan for the treatment of undialyzed uremic patients to delay the progression of CRF. AST-120 attenuates the progression of glomerular sclerosis and interstitial fibrosis in a variety of experimental rat models of CRF. However, the mechanism by which AST-120 delays the progression of CRF had not been clear. We have demonstrated that indoxyl sulfate, a dietary protein metabolite, is a circulating uremic toxin stimulating glomerular sclerosis and interstitial fibrosis, and that AST-120 decreases the serum and urine levels of indoxyl sulfate by adsorbing its precursor, indole, in the intestine. The administration of indoxyl sulfate to uremic rats stimulated the expression of transforming growth factor (TGF)-beta1, tissue inhibitor of metalloproteinase (TIMP)-1 and pro-alpha1(I)collagen in the kidneys. Further, the administration of AST-120 to uremic rats reduced the extent of glomerular sclerosis and interstitial fibrosis as well as the renal expression of TGF-beta1 and TIMP-1, by reducing the serum and urine levels of indoxyl sulfate. We propose the protein metabolite hypothesis that endogenous protein metabolites such as indoxyl sulfate play an important role in the progression of CRF, and that AST-120 is effective in retarding the progression of CRF by removing these protein metabolites through intestinal absorption.
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PMID:Preventive effects of an oral sorbent on nephropathy in rats. 1068 68

This study was constructed to investigate the relationship between renal anaemia and erythropoietin (EPO) concentrations in chronic renal failure (CRF) patients and to evaluate the possible role of the liver. Serum EPO levels were measured in blood samples from 20 CRF patients on hemodialysis (HD), 20 liver cirrhosis (LC) patients, 20 patients having both CRF and LC and undergoing HD, and 20 normal control subjects. Blood cell counts, iron indices (iron, total iron-binding capacity (TIBC) and ferritin), renal function (blood urea nitrogen (BUN) and creatinine), hepatic function (ALT, AST, ALP and bilirubin) investigations were carried out for all the subjects enrolled in this study. CRF patients without LC had serum EPO concentration of 6.21 +/- 0.53 mU/ml (mean +/- SE), which was significantly higher than that in patients having both CRF and LC (4.32 +/- 0.52) (p < 0.01). Both groups showed significantly lower values than the controls (12.75 +/- 0.70) (p < 0.001). LC patients with intact kidneys had significantly higher EPO level (22.70 +/- 1.70) (p < 0.001). No correlation was found between EPO level and any of the hematologic or iron indices.
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PMID:Assessment of erythropoietin levels and some iron indices in chronic renal failure and liver cirrhosis patients. 1068 46

This study was carried out to investigate the relationship between lipoprotein (a) levels and the development of atherosclerosis in chronic renal failure (CRF) patients with the possible role of the liver. Serum Lp (a) levels were measured in samples from 20 CRF patients on hemodialysis (HD), 20 liver cirrhosis (LC) patients, 20 patients having both CRF and LC and undergoing HD, and 20 normal control subjects. Renal function (blood urea nitrogen (BUN) and creatinine), hepatic function (transaminases (ALT and AST), alkaline phosphatase (ALP) and total bilirubin) investigations and serum cholesterol were carried out for all the subjects enrolled in this study. Serum Lp (a) concentration in CRF patients without LC was 87.25 +/- 6.17 mg/dl, which was significantly higher than all the investigated groups (P < 0.001). Lp (a) concentration in patients with both CRF and LC was 24.65 +/- 1.98 mg/dl, which was not significantly different from the controls, but was significantly higher than that in the subjects with LC only (P < 0.001) where the latter group had significantly low Lp (a) values (11.1 +/- 0.99) relative to all the other groups (P < 0.001). Lp (a) correlated positively with cholesterol in all groups except the LC subjects, but did not correlate with age, or renal function in both CRF groups.
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PMID:Serum lipoprotein (a) levels in chronic renal failure and liver cirrhosis patients. Relationship with atherosclerosis. 1068 47

Diabetic nephropathy is a common cause of end-stage renal disease. The administration of an oral adsorbent, AST-120, prevents the progression of chronic renal failure in uremic rats and undialyzed uremic patients. This study was designed to determine if AST-120 slows the progression of diabetic nephropathy using Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a model of non-insulin-dependent diabetic mellitus. At 21 weeks of age the OLETF rats were divided into 2 groups: AST-120-administered OLETF rats (n = 7), and control OLETF rats (n = 7). LETO rats, which are genetically similar to the OLETF rats but not diabetic, were also included. After the oral administration of AST-120 for 65 weeks, renal function and pathological changes were investigated in the 3 groups. The administration of AST-120 to the OLETF rats attenuated the progression of glomerular sclerosis, interstitial fibrosis, tubular injury as well as renal dysfunction, and reduced the serum and urinary levels of indoxyl sulfate. Furthermore, AST-120 administration reduced the interstitial expression of transforming growth factor (TGF)-beta(1) and tissue inhibitor of metalloproteinase (TIMP)-1, as well as interstitial infiltration of macrophages. The TGF-beta(1)-stained interstitial area showed positive correlations with the interstitial fibrosis area, the number of TIMP-1-positive cells, and the number of macrophages, and showed a negative correlation with creatinine clearance. In conclusion, AST-120 reduced the interstitial expression of TGF-beta(1) and TIMP-1, and the interstitial infiltration of macrophages, and ameliorates the progression of diabetic nephropathy in OLETF rats.
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PMID:Oral adsorbent AST-120 ameliorates interstitial fibrosis and transforming growth factor-beta(1) expression in spontaneously diabetic (OLETF) rats. 1087 8


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