Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.14.11.2 (prolyl hydroxylase)
1,814 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An experimental model of pulmonary fibrosis has been developed by dosing rats with one-fifth the LD50 dose of the herbicide paraquat on 5 consecutive days. Approximately 50% of the rats died within 4 days of the completion of dosing, showing macroscopic changes and wet weight increases in the lung consistent with severe oedema. Those animals which died between Days 4 and 10 had markedly increased levels of hydroxyproline in the lung, maximum at Day 6, and increased prolyl hydroxylase activity, maximum at Day 4. These changes, together with an increase in thymidine incorporation into DNA, and increased lung DNA content, were consistent with the development of fibrosis. Measurement of transglutaminase activity in the lung showed marked increases at Days 4 and 10 after completion of dosing. This activity paralleled closely the changes in prolyl hydroxylase activity and became increasingly associated with particulate protein present in the "nuclear pellet" fraction. The presence of zymogen plasma transglutaminase trapped in lung homogenates could not be demonstrated but the contribution by the active plasma transglutaminase (Factor XIIIa) to increases shown at Day 4 cannot be ruled out.
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PMID:Changes in transglutaminase activity in an experimental model of pulmonary fibrosis induced by paraquat. 4 2

The activity of purified prolyl hydroxylase (proline, 2-oxoglutarate dioxygenase, EC 1. 14. 11. 2) was enhanced 3 approximately 8-fold at a low concentration of ferrous ion (1 X 10(-5 M) by addition of bleomycin, a glycopeptide antibiotic with antineoplastic activity and a side effect of producing pulmonary fibrosis. The maximum stimulation was attained at a concentration of 15 microgram/ml bleomycin (about 1 X 10(-5) M), which was approximately equimolar with the ferrous ion, one of the cofactors of this enzyme. Addition of bleomycin to the assay mixture resulted in a change of the optimal concentration of ferrous ion from 2 X 10(-3) M to 1 X 10(-5) M. Changing the order of addition of ferrous ion, enzyme and bleomycin in assay medium before incubation at 37 degrees C, the stimulatory activity was varied. Blemycin A2Cu++(Cu++-chelated bleomycin), which scarcely complexed with Fe++, had no enhancing effects on the enzymatic activity. We discuss the possible reasons as to why the activity of prolyl hydroxylase was enhanced by addition of bleomycin in the assay mixture.
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PMID:Stimulation of prolyl hydroxylase activity by bleomycin. 8 30

The etiology of pulmonary fibrosis remains unclear, and at present there are no definite biochemical markers of its activity. We measured serum and BALF levels of type III procollagen N-terminal peptide (P-III-P), prolyl hydroxylase (PH), and laminin P1 in patients who had undergone radiotherapy for malignant neoplasms, and investigated their value as biochemical markers in a model of pulmonary fibrosis. The following results were obtained: 1) Patients with abnormal liver function had significantly higher serum P-III-P levels and showed a tendency to have higher serum PH levels. If P-III-P or PH are to be used as markers of pulmonary fibrosis, the effect of liver function must be taken into consideration; however, no significant difference was detected with respect to laminin P1 levels. 2) Serum P-III-P levels were significantly elevated by radiotherapy. 3) Laminin P1 levels rose in a similar manner to P-III-P levels after radiotherapy, but no significant change was detected. 4) In most cases, the levels of all markers in BALF were below the threshold of detection, nevertheless all three markers were elevated in a patient who developed diffuse radiation pneumonitis during radiotherapy. Increases in the lymphocyte count were found in BALF of this patient. 5) BALF hyaluronic acid levels were negative in the 3 cases assayed. 6) A significant correlation between P-III-P and laminin P1 in serum was shown, but no significant correlations could be found between the other combinations of markers in serum. Thus it appears that serum P-III-P and laminin P1 are valid biochemical markers of pulmonary fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Type III procollagen N-terminal peptide (P-III-P, prolyl hydroxylase (PH), and laminin P1 levels in serum and BALF of radiotherapy patients]. 132 Jul 8

Cyclic nucleotides play an important role in the regulation of fibroblast proliferation and collagen metabolism. In the present study, the antifibrotic potential of dibutyrylcAMP (Bt2cAMP) was evaluated in the bleomycin (BLM)-hamster model of pulmonary fibrosis. Bt2cAMP (10 mg kg-1, s.c.) or saline (SA, s.c.) was given daily two days prior to the first intratracheal (i.t.) dose of BLM or SA and thereafter throughout the study. BLM or SA was instilled i.t. in three consecutive doses (2.5, 2.0 and 1.5 U 5ml-1 kg-1) at weekly intervals. Hamsters were killed at 7, 14 and 20 days after the third i.t. instillation. Bt2cAMP significantly reduced the contents of lung hydroxyproline and lung thiobarbituric acid reactive substance equivalents in BLM-treated animals at 7 and 14 days. Bt2cAMP significantly elevated lung superoxide dismutase activity in BLM-treated animals at 7 days. Lung prolyl hydroxylase activity was significantly elevated at 14 and 20 days in SABLM- and Bt2cAMPBLM-treated animals. The ratio of cAMP/cGMP was significantly reduced at all time points in SABLM-treated animals but only at 7 and 14 days in Bt2cAMPBLM-treated animals. Bt2cAMP caused no significant changes in lung calcium and calmodulin levels and protein content of the bronchoalveolar lavage. BLM significantly increased various inflammatory cell counts in the lavage at all three time points. The cell counts in the Bt2cAMPBLM groups were generally lower at 7 days and higher at 20 days than those of the SABLM groups. Histological evaluation showed that the lungs of Bt2cAMPBLM-treated hamsters progressed from an inflammatory cell lesion to a fibrotic lesion at a slower rate than the SABLM groups. It was concluded that Bt2cAMP attenuated BLM-induced pulmonary fibrosis in hamsters in part by delaying the acute phase of the inflammatory reaction.
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PMID:Effects of dibutyrylcyclic adenosine monophosphate on bleomycin-induced lung toxicity in hamsters. 137 23

The bleomycin (BL)-hamster model of interstitial pulmonary fibrosis (IPF) is generally associated with increased lung lipid peroxidation, measured as malondialdehyde equivalent (MDAE), calcium and collagen content; and superoxide dismutase (SOD), prolyl hydroxylase (PH) and poly(ADP-ribose) polymerase activities. We found that combined treatment with taurine in drinking water (1%) and niacin IP (250 mg/kg) daily, significantly decreased the BL-induced increases in lung MDAE and calcium content, and SOD, PH and poly(ADP-ribose) polymerase activities. This treatment almost completely ameliorated the BL-induced increases in the lung collagen accumulation as well. Findings of a similar nature were also demonstrated when taurine (2.5%) and niacin (2.5%) were supplemented in the diet of hamsters used in the same BL model of IPF. The diet supplemented with taurine (2.5%), niacin (2.5%), or taurine (2.5%) + niacin (2.5%) also reduced AD-induced increases in lung collagen accumulation, phospholipids, MDAE and SOD activity. It was concluded that diet supplemented with taurine and/or niacin would completely or partially ameliorate chemically-induced pulmonary fibrosis.
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PMID:Taurine and niacin offer a novel therapeutic modality in prevention of chemically-induced pulmonary fibrosis in hamsters. 138 Jul 62

Bleomycin (BLM)-induced lung fibrosis has been shown to be accompanied by the activation of poly(ADP-ribose) polymerase and depletion of nicotinamide adenine dinucleotide (NAD) in the lung. Niacin, a precursor of NAD, was used in the present study to investigate its possible ameliorating effect on BLM-induced pulmonary fibrosis in hamsters. Niacin (500 mg/kg IP) or saline (IP) was injected daily for 16 or 23 days. On day 3, hamsters were treated with BLM (7.5 U/5 mL/kg) or an equivalent volume of saline intratracheally. BLM alone significantly increased lung hydroxyproline levels, bronchoalveolar lavage fluid protein concentration, and various inflammatory cell counts in the lavage in both experiments. In addition, BLM alone elevated prolyl hydroxylase and poly(adenosine-5'-diphosphate [ADP]-ribose) polymerase activities in the 3-week study. Niacin treatment significantly decreased BLM-elevated lung hydroxyproline, prolyl hydroxylase, and poly(ADP-ribose) polymerase activities. Histopathology revealed that niacin treatment attenuated BLM-induced thickened alveolar septa, foci of fibrotic consolidation, and accumulations of inflammatory cells in the parenchyma and air spaces. The ability of niacin to attenuate BLM-induced lung fibrosis in hamsters suggests that it may have potential as an antifibrotic agent in humans.
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PMID:Niacin attenuates bleomycin-induced lung fibrosis in the hamster. 169 27

Oxidant-mediated epithelial injury and repair processes may promote the development of pulmonary fibrosis. The authors examined this hypothesis by inducing oxidant injury in hamsters with intratracheally instilled mixtures of glucose, glucose oxidase (GO) and lactoperoxidase at weekly intervals. Solutions containing denatured GO (DE) served as a control treatment. One and six days after each treatment, anesthetized animals were sacrificed and lavaged, and their lungs and plasma were preserved for further study. Although DE-treatment consistently evoked a transient, neutrophil-rich inflammatory response, no significant biochemical or morphologic changes were detected at the ensuing 6-day time points. In contrast, repeated GO treatments prolonged inflammation and injured the alveolar epithelium, evidenced by significantly greater levels of neutrophils and macrophages in bronchoalveolar lavage fluid (BALF) and increased BALF levels of protein, beta-glucuronidase and lactic dehydrogenase activities. Active GO also altered BALF lymphocytes and monocytes, but no discernable pattern emerged. Fibrotic, consolidated parenchyma appeared after the second and third GO exposures, coinciding with increased levels of total collagen, prolyl hydroxylase activity, and anti-oxidant enzyme activities. Although alveolitis and type II cell hyperplasia were observed after the initial treatment, polyplike nodules covered by hyperplastic, undifferentiated epithelium were evident after the third treatment. After each exposure, GO-treated animals had larger volumes of parenchymal lesion than DE-treated hamsters. These data indicate that normal alveolar epithelial repair processes were greatly disrupted by repeated oxidant injury and suggest that repeated and/or continued epithelial injury may contribute to the development of pulmonary fibrosis.
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PMID:Repeated exposures to enzyme-generated oxidants cause alveolitis, epithelial hyperplasia, and fibrosis in hamsters. 175 May 14

Bleomycin damages cellular DNA and is a potent inducer of pulmonary fibrosis. It has been shown to act through a superoxide-mediated mechanism. We are interested in determining the biochemical mechanisms involved in fibrosis and in this preliminary study we have examined the temporal relationship between early biochemical events associated with DNA damage and fibrosis, in lungs of hamsters after administration of 0.75 unit of bleomycin. The activities of poly(ADP-ribose) synthetase, an enzyme associated with DNA repair, inducible superoxide dismutase (SOD) and prolyl hydroxylase as well as the tissue levels of NAD+ and hydroxyproline in the lung were determined. All three enzyme activities expressed as per milligram DNA or per lung, increased upon bleomycin treatment over the saline-administered controls. Lung poly(ADP-ribose) synthetase activity which is sensitive to DNA breaks, increased first (24% over control in 1 day, P less than 0.0001), attained the maximum value on the 5th day (952% over control, P less than 0.0001), and started to decline thereafter and approached near the control value on 14th day. Bleomycin treatment induced a rapid change in the level of lung NAD+. After 1 day the level of NAD+ was reduced by 42% compared to the control (P less than 0.001), further declined to 65% (P less than 0.001) on the 3rd day, and stayed at that level until the 7th day. On the 14th day, however, the NAD+ level was still lower (29%, P less than 0.05) but approaching the value in the control animals. The activity of prolyl hydroxylase showed significant increase on the 3rd day (50% over control, P less than 0.0001) after bleomycin administration. The enzyme activity continued to increase until the end of the experiment (490% of control, P less than 0.0001, on Day 14). The content of undialyzable hydroxyproline, a marker for collagen, was also increased significantly in the lung tissue on the 3rd day (30% over control, P less than 0.05), continued to increase and reached the highest level on the 14th day (71% over control, P less than 0.001). A significant increase in the activity of SOD (19% over control, P less than 0.001) was seen on the 5th day which continued to increase and attained the highest value on Day 14 (115% over control, P less than 0.0001).(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Poly(ADP-ribose) synthetase activity during bleomycin-induced lung fibrosis in hamsters. 241 86

Orally administered zinc was studied as a protective antifibrotic agent with respect to experimentally caused lung collagen accumulation in rats. Intraperitoneally injected carbon tetrachloride induced a diffuse alveolar damage with interstitial pulmonary fibrosis, and the morphologic findings suggested a primary toxic effect on the lungs. The carbon tetrachloride induction increased significantly the lung to body weight ratio, lung total protein and collagen content, lung total prolyl hydroxylase and galactosylhydroxylysyl glucosyltransferase activities, and daily urinary hydroxyproline excretion. Treatment with 114 mg/L of zinc in the animals' drinking water inhibited the lung prolyl hydroxylase activity and prevented the increases in lung collagen content and urinary hydroxyproline excretion but did not normalize any of the other above parameters. Enhanced lung prolyl hydroxylase activity was noted when a ferrous ion excess was included in the assay in order to reverse the competitive inhibition of the enzyme activity by zinc. It is suggested that zinc has a direct and selective preventive effect on rat lung collagen accumulation by inhibiting procollagen proline hydroxylation.
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PMID:Prevention by zinc of rat lung collagen accumulation in carbon tetrachloride injury. 299 29

Pharmacologic treatment of pulmonary fibrosis has been limited to the use of corticosteroids occasionally combined with other immunosuppressive agents. We tested the ability of a proline analogue that is a potent inhibitor of collagen biosynthesis to prevent the manifestations of bleomycin-induced pulmonary fibrosis in an animal model. Bleomycin sulfate was administered by intratracheal instillation to produce pulmonary fibrosis in male Fischer 344 rats. After 28 days lungs from bleomycin-treated animals had histologic, biochemical, and functional alterations consistent with pulmonary fibrosis. Vital capacity and compliance were reduced to 62% and 41% of their respective control values. Lung prolyl hydroxylase activity doubled during the first week after bleomycin, at a time when total lung collagen content remained unchanged. Thereafter total lung collagen content slowly rose to 72% above control values at 28 days. We administered the proline analogue DHP at a dose that completely inhibited the elevated levels of lung prolyl hydroxylase activity. Pulmonary collagen content of animals treated with DHP was only minimally elevated, and functional abnormalities were reduced. Pulmonary compliance increased significantly from 0.25 to 0.44 ml/cm of H2O, and vital capacity increased from 3.94 to 5.65 ml. These studies suggest that proline analogues offer potential for modifying the manifestations of pulmonary fibrosis that occur as a consequence of acute lung injury. Elevation of lung prolyl hydroxylase activity is an early even that serves as a useful index of the acute lung injury produced by bleomycin.
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PMID:Bleomycin-induced pulmonary fibrosis in the rat. Prevention with an inhibitor of collagen synthesis. 615 35


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