A Myeloperoxidase-Specific Assay Based upon Bromide-Dependent Chemiluminescence of Luminol

As, Haqqani; Sandhu, JK; Birnboim, H.C.

doi:10.1006/abio.1999.4206

Cited by 53 publications

(37 citation statements)

References 27 publications

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“…Serum amylase activity was measured colorimetrically using the Phadebas assay (Pharmacia Diagnostics, Portage, MI). Neutrophil sequestration in pancreas and lung was quantitated by measuring tissue MPO activity as described previously (20). Trypsin activity was measured fluorometrically, as described previously (23).…”

Section: Methodsmentioning

confidence: 99%

Nelfinavir/ritonavir reduces acinar injury but not inflammation during mouse caerulein pancreatitis

Singh

Bren

Algeciras‐Schimnich

et al. 2009

American Journal of Physiology-Gastrointestinal and Liver Physi

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There is no clinical treatment that reduces acinar injury during pancreatitis. Human immunodeficiency virus (HIV) protease inhibitors (PI), including nelfinavir (NFV) and ritonavir (RTV), may reduce the rate of pancreatitis in HIV-infected patients. Since permeability transition pore (PTPC)-mediated mitochondrial dysfunction occurs during pancreatitis, and we have shown that PI prevents PTPC opening, we studied its effects in a model of pancreatitis. The effect of NFV plus RTV (NFV/RTV) or vehicle on caerulein-induced pancreatitis in mice was compared by measuring changes in mitochondrial membrane potential in vitro and cytochrome c leakage in vivo. Histological and inflammatory makers were also compared. NFV/RTV improved DiOC6 retention in acini exposed to caerulein in vitro. In vivo NFV prevented cytosolic leakage of cytochrome c and reduced pancreatic acinar injury, active caspase-3 staining, TUNEL-positive acinar cells, and serum amylase ( P < 0.05). Conversely, trypsin activity, serum cytokine levels, and pancreatic and lung inflammation were unaffected. NFV/RTV reduces pancreatic injury and acinar cell death in experimental mouse caerulein-induced pancreatitis but does not impact inflammation.

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Section: Methodsmentioning

confidence: 99%

Nelfinavir/ritonavir reduces acinar injury but not inflammation during mouse caerulein pancreatitis

Singh

Bren

Algeciras‐Schimnich

et al. 2009

American Journal of Physiology-Gastrointestinal and Liver Physi

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“…The sample was then centrifuged (10,000 g for 5 min at 4°C), and the supernatant was used for MPO assay. The MPO assay is a modification of the bromide-dependent chemiluminescence technique as described by Haqqani et al (18).…”

Section: Methodsmentioning

confidence: 99%

Inhibition of cyclooxygenase-2 ameliorates the severity of pancreatitis and associated lung injury

Song

Bhagat

Singh

et al. 2002

American Journal of Physiology-Gastrointestinal and Liver Physi

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Inhibition of cyclooxygenase-2 ameliorates the severity of pancreatitis and associated lung injury. Am J Physiol Gastrointest Liver Physiol 283: G1166-G1174, 2002. First published July 17, 2002 10.1152/ajpgi.00370.2001.-Cyclooxygenase-2 (COX-2), a widely distributed enzyme, plays an important role in inflammation. We have studied the role of COX-2 in acute pancreatitis and pancreatitis-associated lung injury using both the pharmacological inhibition of COX-2 and genetic deletion of COX-2. Pancreatitis was induced in mice by 12 hourly injections of cerulein. The severity of pancreatitis was assessed by measuring serum amylase, pancreatic trypsin activity, intrapancreatic sequestration of neutrophils, and acinar cell necrosis. The severity of lung injury was evaluated by measuring lactate dehydrogenase levels in the bronchoalveolar lavage fluid and by quantitating neutrophil sequestration in the lung. In both the pharmacologically inhibited and genetically altered mice, the severity of pancreatitis and pancreatitis-associated lung injury was reduced compared with the noninhibited strains of COX-2-sufficient mice. This reduction in injury indicates that COX-2 plays an important proinflammatory role in pancreatitis and its associated lung injury. Our findings support the concept that COX-2 inhibitors may play a beneficial role in the prevention of acute pancreatitis or in the reduction of its severity.prostaglandin; proinflammatory; cerulein; neutrophil; heat shock protein 70; inducible nitric oxide synthase; trypsin; myeloperoxidase CLINICAL ACUTE PANCREATITIS can present with varying degrees of severity. It is frequently associated with lung injury, manifesting as the adult respiratory distress syndrome. Approximately 80% of patients experience a mild attack with minimal sequelae; however, the other 20% of patients develop severe disease with a mortality rate that can reach 40% (37). The factors that determine the development and ultimate severity of pancreatitis are still not fully understood.The initiation of prostanoid synthesis from arachidonic acid involves the enzyme cyclooxygenase (COX), an enzyme that is also referred to as PGH synthase or PG endoperoxide synthase, because it is also the ratelimiting enzyme for PGE 2 synthesis. Two COX isoforms have been identified: a constitutive form (COX-1), which is thought to have an important housekeeping function, and an inducible form (COX-2), which has been implicated as an important proinflammatory mediator (21). COX-2 is upregulated in response to a variety of proinflammatory stimuli including IL-1, TNF-␣, and bacterial lipopolysaccharide (1, 9, 23). COX-2 mRNA and protein levels are increased during experimental pancreatitis, but the role of COX-2 in pancreatitis has not been well defined (13).In this communication, we report the result of studies dealing with the role of COX-2 in acute pancreatitis and pancreatitis-associated lung injury. In our studies, some mice were pretreated with COX-2 inhibitors (15, 33), whereas other mice were bred with genetic deleti...

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“…Details of extraction of myeloperoxidase from tumor fractions have been previously described (42). An assay specific for myeloperoxidase was used (47). The frequency of hypoxanthine phosphoribosyltransferase (hprt Ϫ ) mutants was measured in cells growing ex vivo as described previously (42).…”

Section: Measurement Of Neutrophil Content and Hprt ϫ Mutants In Tumors-mentioning

confidence: 99%

Selective Nitration of Histone Tyrosine Residues in Vivo in Mutatect Tumors

Haqqani¹,

Kelly²,

Birnboim³

2002

Journal of Biological Chemistry

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Nitric oxide-derived reactive species have been implicated in many disorders. Protein nitrotyrosine is often used as a stable marker of these reactive species. Using immunohistochemistry, we have previously detected nitrotyrosine in murine Mutatect tumors, where neutrophils are the principal source of nitric oxide. We now report on the identification of several prominent nitrotyrosine-containing proteins. Using Western blot analysis, nitrotyrosine in higher molecular mass proteins (>20 kDa) was detected in tumors containing a high number of neutrophils but not in tumors with fewer neutrophils. Staining for nitrotyrosine was consistently seen in low molecular mass proteins (<15 kDa), regardless of the level of neutrophils. Protein nitrotyrosine was not seen in Mutatect cells growing in vitro. Treatment with nitric oxide donors produced nitration of <15-kDa proteins, but only after extended periods. These small proteins, both from tumors and cultured cells, were identified by mass spectrometry to be histones. Only a subset of tyrosine residues was nitrated. Selective nitration may reflect differential accessibility of different tyrosine residues and the influence of neighboring residues within the nucleosome. The prominence of histone nitration may reflect its relative stability, making this post-translational modification a potentially useful marker of extended exposure of cells or tissues to nitric oxide-derived reactive species.Nitric oxide (NO ⅐ ) 1 -derived reactive nitrogen oxide species (RNOS) are cytotoxic and mutagenic, and have been implicated in the pathogenesis of several inflammatory disorders (1-9). Inflammatory cells, such as macrophages, monocytes, and neutrophils produce a relatively large amount of RNOS. These reactive species may exert deleterious effects by modifying or damaging various cellular targets including DNA, lipids, and proteins (10 -12). One of the targets in proteins is tyrosine (Tyr), which can be converted into a fairly stable end-product, 3-nitrotyrosine (NTyr) (13). The presence of free NTyr amino acids or NTyr-containing proteins in biological samples is used as a molecular marker of RNOS production in a tissue (13). In addition, nitration of Tyr residues in proteins may alter protein function (4, 14 -17), which may have both physiological and pathological significance. The presence of protein NTyr has been reported in inflammatory disorders such as Helicobacter pylori infection, Crohn's disease, ulcerative colitis, Wegener's granulomatosis, cystic fibrosis, asthma, obliterative bronchiolitis, and rheumatoid arthritis (2-9). The level of protein NTyr has been found to correlate with the severity of inflammatory diseases (18 -20). Protein NTyr has also been detected in some tumors (21-24). A high level of protein NTyr correlates with poor outcome in melanoma patients (25). Although a high level of protein NTyr has been detected in vivo in human or animal diseases, only a limited number of NTyr-containing proteins has been identified (26 -34).Several methods have been employed to...

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A Myeloperoxidase-Specific Assay Based upon Bromide-Dependent Chemiluminescence of Luminol

Cited by 53 publications

References 27 publications

Nelfinavir/ritonavir reduces acinar injury but not inflammation during mouse caerulein pancreatitis

Nelfinavir/ritonavir reduces acinar injury but not inflammation during mouse caerulein pancreatitis

Inhibition of cyclooxygenase-2 ameliorates the severity of pancreatitis and associated lung injury

Selective Nitration of Histone Tyrosine Residues in Vivo in Mutatect Tumors

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