Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.4.4 (adenosine deaminase)
 5,136 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. A low protein diet prevents the development of proteinuria and glomerular damage in adriamycin experimental nephrosis without affecting renal haemodynamics. In this study the hypothesis was tested as to whether protein restriction is able to modulate the purine metabolic cycle and related enzymes such as xanthine oxidase, one of the putative effectors of adriamycin nephrotoxicity. 2. Renal activities of xanthine oxidase and purine nucleoside phosphorylase were markedly depressed in adriamycin-treated rats fed a 9% casein (low protein) diet compared with the group fed a 22% casein (normal protein) diet both 1 day after adriamycin administration and at the time of appearance of heavy proteinuria (day 15), whereas the activity of renal adenosine deaminase was unchanged. 3. The concentrations of the metabolic substrates of xanthine oxidase, i.e. hypoxanthine and xanthine, were constantly lower in renal homogenates of rats fed a low protein diet compared with those on a normal protein diet. In urine, uric acid, the product of hypoxanthine-xanthine transformation, was lower 1 day after adriamycin injection in protein-restricted rats compared with the group on a normal protein diet which showed a marked increase in its excretion. At the same time, the urinary efflux of adenosine 5'-monophosphate, which is the precursor nucleotide of the above-mentioned nucleosides and bases, was very high in rats fed a low protein diet, whereas it was absent in the group on a normal protein diet. 4. The progressive increment in proteinuria of glomerular origin (i.e. increased excretion of albumin and transferrin) typical of adriamycin-treated rats fed a normal protein diet was inhibited in the protein-restricted animals, which were normoproteinuric on day 10 and were only slightly proteinuric on day 15. 5. Like protein restriction, the pharmacological suppression of renal xanthine oxidase by dietary tungstate and the scavenging by dimethylthiourea of the putative free radical deriving from the action of xanthine oxidase, were associated with a similar (quantitative and qualitative) inhibition of glomerular proteinuria. 6. These data demonstrate that dietary protein restriction is associated with a block in purine metabolism within the kidney due to a marked reduction in the activities of two main enzymes of the cycle, i.e. purine nucleoside phosphorylase and xanthine oxidase, the latter being a putative effector of adriamycin nephrotoxicity. The partial reduction of proteinuria induced by a low protein diet is quantitatively and qualitatively comparable with the reduction induced by the specific block of renal xanthine oxidase or by the scavenging of OH.deriving from hypoxanthine and xanthine transformation.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Effect of dietary protein restriction on renal purines and purine-metabolizing enzymes in adriamycin nephrosis in rats: a mechanism for protection against acute proteinuria involving xanthine oxidase inhibition. 217 53

Puromycin aminonucleoside (PAN) toxicity was totally inhibited in the rat in vivo and in cultured glomerular epithelial cells (GECs) in vitro using the adenosine deaminase (ADA) inhibitor, 2'-deoxycoformycin (DCF). DCF completely inhibited ADA activity in glomeruli and protected against the development of PAN nephrosis; the 24-h urinary protein excretion of treated rats compared with controls (PAN rats) 9 days after PAN injection was 16 +/- 2 mg and 524 +/- 55 mg, respectively (p < .01). Morphological examination also demonstrated that the glomerular epithelial cells were protected against PAN-induced damage. Furthermore, when DCF was added to the first passage of GECs simultaneously with PAN, the adenosine triphosphate contents of remnant GECs on culture substrata increased in a dose-dependent manner, and PA toxicity was completely inhibited by 10(-4) M DCF. The order of ADA activity in glomeruli from various species was as follows: rat > monkey > guinea pig > dog > rabbit > mouse. High activity of ADA in the glomerulus was limited to species in which PAN induced nephrosis. Additionally, DCF increased glomerular cyclic AMP contents, resulting from enhanced adenosine accumulation in the pericellular space. These results indicate that the pathogenesis of PAN toxicity is closely related to adenosine metabolism and that ADA plays a key role in this model. Furthermore, we speculate that DCF contributes to the inhibition of reactive oxygen metabolites by decreasing the substrate of xanthine oxidase and/or increasing pericellular adenosine accumulation.
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PMID:An adenosine deaminase inhibitor prevents puromycin aminonucleoside nephrotoxicity. 901 23

This review summarizes current strategies in the treatment of patients with pleural effusion. To determine whether a patient has a transudative or exudative pleural effusion, Light's criteria should be applied to measure the concentrations of protein and lactate dehydrogenase (LDH) in the pleural fluid and serum. If the effusion is transudative, therapy should be directed toward the underlying congestive heart failure, cirrhosis, or nephrosis. Consideration should be given to pleurodesis with a sclerosant if patients with recurrent transudative effusion have severe dyspnea due to their effusion. If the effusion is exudative, attempts should be made to define the etiology. The diagnosis of pleural malignancy is most easily established via pleural fluid cytology. If this is negative and the patient is suspected of having pleural malignancy, thoracoscopy is indicated. The concentrations of adenosine deaminase and gamma-interferon in pleural fluid are useful in the diagnosis of pleural tuberculosis. Patients with pneumonia and pleural effusion should undergo therapeutic thoracentesis; the pleural fluid should be Gram-stained and cultured, and the differential cell count, glucose and LDH concentration, and pH should be determined. Indicators of a poor prognosis include the presence of frank pus, a positive Gram-stain, a pleural glucose concentration of less than 2.2 mmol/L, a pH less than 7.00, the presence of pleural loculations, and an LDH concentration greater than three times the upper limit of normal in serum. If the pleural fluid cannot be completely evacuated because of loculations, intrapleural thrombolytic therapy should be considered. If thrombolytics are ineffective, thoracoscopy or thoracotomy with decortication should be performed. Dyspneic patients with malignant pleural effusions whose dyspnea is relieved with therapeutic thoracentesis should be considered for pleurodesis using a tetracycline derivative. Talc is not recommended because it induces acute respiratory distress syndrome in about 5% of patients, with an overall mortality of 1%.
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PMID:Management of pleural effusions. 1092 61