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1.
Korean Journal of Otolaryngology - Head and Neck Surgery ; : 176-181, 2019.
Article in Korean | WPRIM | ID: wpr-830054

ABSTRACT

BACKGROUND AND OBJECTIVES@#To find more accurate way to determine the location of parotid tumors that cross anatomical criteria for the facial nerve (FN).SUBJECTS AND METHOD: Two hundred patients were included in the study and retrospectively studied. Five anatomical criteria were used to predict the location of parotid tumors on computed tomography (CT). Deep portion of tumors was measured and then, cut-off value was obtained after receiver operator curve analysis. The location of tumor was predicted by using the cut-off value and by the conventional way, in which the side where most of the tumor is located is determined as the tumor site.@*RESULTS@#The parotid tumors were located in superficial lobes in 148 cases, and in deep lobes in 52 cases by operative record. The tumors that cross the anatomical criteria were defined as ‘crossing tumor.’ The cut-off values for prediction of ‘crossing tumor’ location on CT were 6.7 mm for anatomical line, 6.4 mm for FN line, 11.2 mm for retromandibular vein, 4.9 mm for Utrecht line and 3.8 mm for Conn's arc. The accuracy of 5 anatomical criteria for ‘crossing tumor’ was between 55.9% and 81.6% when the cut-off value was used, whereas the accuracy was between 25.7% and 68.9% when conventional way was used.@*CONCLUSION@#In cases of ‘crossing tumor,’ the cut-off value obtained by measurement of deep portion of tumor can be applied to improve the diagnostic performance for the prediction of tumor location.

3.
Korean Journal of Otolaryngology - Head and Neck Surgery ; : 176-181, 2019.
Article in Korean | WPRIM | ID: wpr-760104

ABSTRACT

BACKGROUND AND OBJECTIVES: To find more accurate way to determine the location of parotid tumors that cross anatomical criteria for the facial nerve (FN). SUBJECTS AND METHOD: Two hundred patients were included in the study and retrospectively studied. Five anatomical criteria were used to predict the location of parotid tumors on computed tomography (CT). Deep portion of tumors was measured and then, cut-off value was obtained after receiver operator curve analysis. The location of tumor was predicted by using the cut-off value and by the conventional way, in which the side where most of the tumor is located is determined as the tumor site. RESULTS: The parotid tumors were located in superficial lobes in 148 cases, and in deep lobes in 52 cases by operative record. The tumors that cross the anatomical criteria were defined as ‘crossing tumor.’ The cut-off values for prediction of ‘crossing tumor’ location on CT were 6.7 mm for anatomical line, 6.4 mm for FN line, 11.2 mm for retromandibular vein, 4.9 mm for Utrecht line and 3.8 mm for Conn's arc. The accuracy of 5 anatomical criteria for ‘crossing tumor’ was between 55.9% and 81.6% when the cut-off value was used, whereas the accuracy was between 25.7% and 68.9% when conventional way was used. CONCLUSION: In cases of ‘crossing tumor,’ the cut-off value obtained by measurement of deep portion of tumor can be applied to improve the diagnostic performance for the prediction of tumor location.


Subject(s)
Humans , Facial Nerve , Methods , Parotid Gland , Parotid Neoplasms , Retrospective Studies , Veins
4.
Chonnam Medical Journal ; : 178-186, 2017.
Article in English | WPRIM | ID: wpr-788391

ABSTRACT

Recepteur d'origine nantais (RON) is a receptor tyrosine kinase belonging to the subfamily of which c-MET is the prototype. Large epidemiologic studies have confirmed the strong association between RON and gastric cancer development. Constitutive activation of RON signaling directly correlates with tumorigenic phenotypes of gastric cancer and a poor survival rate in advanced gastric cancer patients. In this review, we focus on recent evidence of the aberrant expression and activation of RON in gastric cancer tumors and provide insights into the mechanism of RON signaling associated with gastric cancer progression and metastasis. Current therapeutics against RON in gastric cancer are summarized.


Subject(s)
Humans , Epidemiologic Studies , Neoplasm Metastasis , Phenotype , Protein-Tyrosine Kinases , Proto-Oncogene Proteins c-met , Stomach Neoplasms , Survival Rate
5.
Korean Journal of Otolaryngology - Head and Neck Surgery ; : 565-569, 2017.
Article in Korean | WPRIM | ID: wpr-651325

ABSTRACT

BACKGROUND AND OBJECTIVES: The biological activity in antibacterial and antioxidative action of essential oils (EOs) have been investigated. In this study, we tried to evaluate the effects of Chamaecyparis obtusa EOs on producing chemical mediators by peripheral blood mononuclear cells (PBMCs). SUBJECTS AND METHOD: PBMCs from healthy volunteers were stimulated with lipopolysaccharide (LPS) and phytohaemagglutinin (PHA) in the presence of varying concentrations of EOs. Cytotoxic effects of EOs were measured using an aqueous cell proliferation assay kit and supernatants were analyzed using enzyme-linked immunosorbent assay. Tumor necrosis factor-α (TNF-α), interleukin-5, and interferon-γ (INF-γ) protein levels were measured to determine the anti-inflammatory effects of essential oil. RESULTS: EOs were found to have cytotoxic effects on PBMCs at levels of over 1%. EOs not only could induce PBMCs to produce chemical mediators, but it also significantly inhibited the LPS induced TNF-α and INF-γ productions as well as the PHA induced INF-γ production. CONCLUSION: EOs had cytotoxic effects at high concentrations and modulated chemical mediator productions from PBMC. These data suggest that EOs could be used to treat immunologic or inflammatory diseases.


Subject(s)
Cell Proliferation , Chamaecyparis , Enzyme-Linked Immunosorbent Assay , Healthy Volunteers , Interleukin-5 , Methods , Necrosis , Oils, Volatile
6.
Chonnam Medical Journal ; : 178-186, 2017.
Article in English | WPRIM | ID: wpr-89703

ABSTRACT

Recepteur d'origine nantais (RON) is a receptor tyrosine kinase belonging to the subfamily of which c-MET is the prototype. Large epidemiologic studies have confirmed the strong association between RON and gastric cancer development. Constitutive activation of RON signaling directly correlates with tumorigenic phenotypes of gastric cancer and a poor survival rate in advanced gastric cancer patients. In this review, we focus on recent evidence of the aberrant expression and activation of RON in gastric cancer tumors and provide insights into the mechanism of RON signaling associated with gastric cancer progression and metastasis. Current therapeutics against RON in gastric cancer are summarized.


Subject(s)
Humans , Epidemiologic Studies , Neoplasm Metastasis , Phenotype , Protein-Tyrosine Kinases , Proto-Oncogene Proteins c-met , Stomach Neoplasms , Survival Rate
7.
Korean Journal of Otolaryngology - Head and Neck Surgery ; : 770-774, 2016.
Article in Korean | WPRIM | ID: wpr-653250

ABSTRACT

BACKGROUND AND OBJECTIVES: Snoring is a condition that affects a large percentage of population and is associated with various medical and social complications. However, there are only few published reports investigating the effects of chronic snoring exposure on hearing. In the present study, we examined whether there is an association between chronic snoring noise exposure and noise induced hearing impairment not only in snorers but also in their spouses. Subjects and MethodZZSixty snorers and 27 spouses under the age of 55 were recruited. All participants had more than 5 years of exposure to snoring. Questionnaire for snoring and pure tone audiometry were conducted. Subjects were classified into normal hearing group and hearing impairment group. SUBJECTS AND METHOD: Sixty snorers and 27 spouses under the age of 55 were recruited. All participants had more than 5 years of exposure to snoring. Questionnaire for snoring and pure tone audiometry were conducted. Subjects were classified into normal hearing group and hearing impairment group. RESULTS: Forty percent of snorers and 25.9% of spouses had hearing impairment. The snorers with hearing impairment had longer duration of snoring than the snorers with normal hearing. However, there were no statistical differences in loudness of snoring between the two groups. In the spouse group, there were statistical differences in loudness of exposed snoring and in duration of snoring exposure between the hearing impairment group and the normal hearing group. CONCLUSION: The result of this study indicated that chronic exposure to snoring noise may be associated with hearing impairment in snorers and their spouses. But in the snorers, further studies are required to identify the factors other than snoring noise associated with hearing impairment.


Subject(s)
Humans , Audiometry , Hearing Loss , Hearing , Methods , Noise , Snoring , Spouses
8.
The Korean Journal of Internal Medicine ; : 40-45, 2016.
Article in English | WPRIM | ID: wpr-149376

ABSTRACT

BACKGROUND/AIMS: To evaluate a new monoclonal antibody for Helicobacter pylori urease in gastric tissue. METHODS: A total of 107 volunteers were enrolled. All subjects underwent a 13C-urea breath test and esophagogastroduodenoscopy. Gastric aspirates were analyzed for pH and ammonia. Six biopsy specimens in the gastric antrum and body were obtained for a rapid urease test and histology. The new monoclonal antibody-based H. pylori urease test (HPU) was performed to rapidly and qualitatively detect urease in two biopsy specimens. RESULTS: H. pylori infection was diagnosed in 73 subjects. The sensitivity and specificity of the HPU was 89% and 74%, respectively. The subjects were divided into two groups: one with true-positive and true-negative HPU results (n = 90) and the other with false-positive and false-negative HPU results (n = 17). Across all subjects, ammonia levels were 900.5 +/- 646.7 and 604.3 +/- 594.3 mumol/L (p > 0.05), and pH was 3.37 +/- 1.64 and 2.82 +/- 1.51 (p > 0.05). Sensitivity was higher in the presence of atrophic gastritis or intestinal metaplasia. CONCLUSIONS: HPU detected H. pylori in approximately 10 min. Gastric aspirate ammonia and pH levels did not affect the test results. Sensitivity was good in the presence of atrophic gastritis or intestinal metaplasia.


Subject(s)
Adult , Female , Humans , Male , Middle Aged , Antibodies, Monoclonal/immunology , Bacterial Proteins/analysis , Biomarkers/analysis , Biopsy , False Negative Reactions , False Positive Reactions , Gastritis, Atrophic/diagnosis , Helicobacter Infections/diagnosis , Helicobacter pylori/enzymology , Immunologic Tests , Metaplasia , Predictive Value of Tests , Pyloric Antrum/microbiology , Reproducibility of Results , Time Factors , Urease/analysis , Workflow
9.
Chonnam Medical Journal ; : 6-14, 2014.
Article in English | WPRIM | ID: wpr-788283

ABSTRACT

This study was designed to evaluate the efficacy of an orally administered aqueous extract of glutinous rice (GRE) to protect against acute gastric mucosal lesions induced by ethanol, indomethacin, and water immersion restraint stress in rats and to characterize the active substances responsible for the protection. GRE was shown to dose-dependently prevent the gastric lesions induced by the above ulcerogenic treatments at doses of 30 to 300 mg/kg. GRE treatment increased the gastric mucin content and partially blocked the ethanol-induced depletion of the gastric mucus layer. Also, it increased the nonprotein sulfhydryl concentration in the gastric mucosa. The gastroprotective action of GRE was markedly enhanced by co-treatment with 4-8 mg/kg tea extracts. The activity of GRE was completely lost by heat treatment at 80degrees C for 3 min or treatment with 0.01% pepsin at 37degrees C for 1 h. Protein extraction studies indicated that prolamins are involved in the gastroprotective activity of GRE. Our results suggest that glutinous rice proteins are useful for the prevention and treatment of gastritis and peptic ulcer.


Subject(s)
Animals , Rats , Ethanol , Gastric Mucins , Gastric Mucosa , Gastritis , Hot Temperature , Immersion , Indomethacin , Mucus , Pepsin A , Peptic Ulcer , Prolamins , Tea , Ulcer , Water
10.
Chonnam Medical Journal ; : 6-14, 2014.
Article in English | WPRIM | ID: wpr-111166

ABSTRACT

This study was designed to evaluate the efficacy of an orally administered aqueous extract of glutinous rice (GRE) to protect against acute gastric mucosal lesions induced by ethanol, indomethacin, and water immersion restraint stress in rats and to characterize the active substances responsible for the protection. GRE was shown to dose-dependently prevent the gastric lesions induced by the above ulcerogenic treatments at doses of 30 to 300 mg/kg. GRE treatment increased the gastric mucin content and partially blocked the ethanol-induced depletion of the gastric mucus layer. Also, it increased the nonprotein sulfhydryl concentration in the gastric mucosa. The gastroprotective action of GRE was markedly enhanced by co-treatment with 4-8 mg/kg tea extracts. The activity of GRE was completely lost by heat treatment at 80degrees C for 3 min or treatment with 0.01% pepsin at 37degrees C for 1 h. Protein extraction studies indicated that prolamins are involved in the gastroprotective activity of GRE. Our results suggest that glutinous rice proteins are useful for the prevention and treatment of gastritis and peptic ulcer.


Subject(s)
Animals , Rats , Ethanol , Gastric Mucins , Gastric Mucosa , Gastritis , Hot Temperature , Immersion , Indomethacin , Mucus , Pepsin A , Peptic Ulcer , Prolamins , Tea , Ulcer , Water
11.
Gut and Liver ; : 30-34, 2013.
Article in English | WPRIM | ID: wpr-214014

ABSTRACT

BACKGROUND/AIMS: The objective of this study was to evaluate a monoclonal antibody-based test to detect Helicobacter pylori-specific antigen in gastric aspirates from humans. METHODS: Sixty-one volunteers were enrolled in the study. All of the subjects underwent a 13C-urea breath test (UBT) before esophagogastroduodenoscopy. Gastric aspirates were analyzed for pH and ammonia and used for polymerase chain reaction (PCR), culture, and monoclonal antibody-based detection of H. pylori. Multiple biopsies of the gastric antrum and body were obtained for a rapid urease test (RUT) and histological evaluation. RESULTS: Thirty-six subjects were H. pylori-positive and 25 were H. pylori-negative according to the UBT results. Compared with the H. pylori-negative subjects, H. pylori-positive subjects had a higher pH (4.77+/-1.77 vs 3.49+/-1.30, p<0.05) and ammonia level (1,130.9+/-767.4 vs 184.2+/-126.3, p<0.0001). The sensitivities and specificities of the PCR test, RUT, culture test, and monoclonal antibody-based test were 100% and 72%, 89% and 100%, 47% and 100%, and 78% and 100%, respectively. CONCLUSIONS: The monoclonal antibody-based test for diagnosing H. pylori infection in gastric aspirates has increased sensitivity compared with the culture test and specificity as high as that of the RUT. The test may be useful as an additive test for examining gastric aspirates.


Subject(s)
Ammonia , Biopsy , Breath Tests , Endoscopy, Digestive System , Helicobacter , Helicobacter pylori , Hydrogen-Ion Concentration , Polymerase Chain Reaction , Pyloric Antrum , Sensitivity and Specificity , Urease
12.
The Korean Journal of Gastroenterology ; : 27-32, 2010.
Article in Korean | WPRIM | ID: wpr-158683

ABSTRACT

BACKGROUND/AIMS: Helicobacter pylori (H. pylori) transmission route is not yet clearly understood. Isolating H. pylori from stool, saliva, and vomitus is very difficult. However, H. pylori could be cultured from feces in the setting of rapid gastrointestinal tract transit. The aim of this study was to isolate H. pylori by culture and PCR in the rectum and terminal ileum during colonoscopy. METHODS: Twenty subjects with positive UBT (urea breath test) were included. We performed polymerase chain reaction (PCR) test and culture of H. pylori with the rectal fluid and terminal ileal fluid during colonoscopy. RESULTS: H. pylori was cultured with rectal fluid from 9 (45.0%) of 20 subjects and with ileal fluid from 11 (55.0%) of 20 subjects. H. pylori was a little more frequently cultured from the terminal ileal fluid than the rectal fluid without statistical significance (p>0.05). PCR test detected flaA (16/20, 80.0% and 17/20, 85.0%), 16S rRNA gene (16/20, 80.0% and 17/20, 85.0%), cagA (10/20, 50.0% and 12/20, 60.0%), and ureC (9/20, 45% and 11/20, 54.5%) from the rectal fluid and the terminal ileal fluid, respectively. The specificity and sensitivity of ureC were 100%. CONCLUSIONS: H. pylori could be cultured from the rectal fluid and terminal ileal fluid in the setting of rapid gastrointestinal tract transit. These results suggest of fecal-oral transmission of H. pylori.


Subject(s)
Adult , Female , Humans , Male , Middle Aged , Antigens, Bacterial/genetics , Bacterial Proteins/genetics , Breath Tests , Electrolytes/administration & dosage , Feces/microbiology , Helicobacter Infections/diagnosis , Helicobacter pylori/genetics , Ileum/microbiology , Polyethylene Glycols/administration & dosage , Polymerase Chain Reaction , RNA, Ribosomal, 16S/genetics , Rectum/microbiology , Sensitivity and Specificity , Urea/analysis , Urease/genetics
13.
The Korean Journal of Gastroenterology ; : 164-169, 2007.
Article in Korean | WPRIM | ID: wpr-147156

ABSTRACT

BACKGROUND/AIMS: Telomeres are simple repeat elements located at each chromosome end of eukaryotic cells. The main function of telomeres is to cap the chromosome end and protect it from enzymatic attack. Telomerase that facilitates the synthesis of telomere has been detected in not only cancer but also precancerous lesion. In this study, we compared the telomerase expression between low grade and high grade colorectal tubular adenoma. METHODS: Among thissues from forty eight patients with colorectal tubular adenoma (23 low grade and 25 high grade colorectal dysplasia), telomerase expressions were evaluated by immunohistochemical staining. RESULTS: We classified 48 patients into two groups by the extent of nuclei staining pattern. High telomerase expression was a group which showed staining nucleus pattern above 50% in tubular adenoma. Low telomerase expression was a group which showed staining pattern nucleus below 50%. Twelve in 25 high grade colorectal dysplasia showed high telomerase expression (48%). Only one in 23 low grade colorectal dysplasia showed high telomerase expression (4%). Telomerase expression was much higher in the tissues from the patients with high grade than in those with low grade colorectal dysplasia (p<0.05). CONCLUSIONS: Activation of telomerase may be related to the malignant potential in colorectal epithelial cells. Further studies are needed to define the role of telomerase in colorectal tumorigenesis.


Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Adenocarcinoma/enzymology , Colorectal Neoplasms/enzymology , Immunohistochemistry , Neoplasm Staging , Retrospective Studies , Telomerase/immunology
14.
Korean Journal of Medicine ; : 293-301, 2006.
Article in Korean | WPRIM | ID: wpr-189991

ABSTRACT

BACKGROUND: Human YB-1 is a transcription factor that binds to the inverted CCAAT box in the promoter region of a variety of genes such as PCNA, DNA polymerase and MDR. In this study we evaluated the effect of YB-1 antisense oligonucleotides on tumor cell growth. METHODS: Chang liver, HepG2 and CT-26 cells were cultured as immortalized cell lines. The MTT (3-[4,5-dimethylthiazol-2-yl] 2,5-diphenyltetrazolium bromide) assay, Northern blot and flow cytometric analyses were used to determine cell growth, gene expression and cell cycle changes. In an animal model, CT-26 cells were injected into Balb/c mice to induce tumor; YB-1 antisense oligonucleotides were injected into the tail vein or tumor tissue of the mice; change of tumor size was then measured. RESULTS: Phosphorothioated YB-1 antisense oligonucleotides suppressed the proliferation of the immortalized liver cells (Chang liver cells) and a variety of cancer cells (HepG2 and CT-26 cells); however, it did not inhibit normal cell growth. The DOTAP/antisense oligonucleotide mixture showed stronger effects on cell proliferation than did the antisense oligonucleotide alone. The YB-1 antisense oligonucleotide decreased specific expression of the YB-1 mRNA in the immortalized cancer cell lines. Flow cytometric analysis revealed that the inhibition of cell proliferation might have been due to a decrease in the S phase of the cell cycle. We found that in an animal tumor model, the administration of the YB-1 antisense oligonucleotide, in the vein or tumor tissues, decreased the tumor size significantly. CONCLUSIONS: These results suggest that the YB-1 antisense oligonucleotide may inhibit growth of a variety of cancer cells.


Subject(s)
Animals , Humans , Mice , Blotting, Northern , Cell Cycle , Cell Line , Cell Proliferation , DNA , Gene Expression , Liver , Models, Animal , Oligonucleotides, Antisense , Proliferating Cell Nuclear Antigen , Promoter Regions, Genetic , RNA, Messenger , S Phase , Transcription Factors , Veins
15.
Cancer Research and Treatment ; : 444-449, 2002.
Article in English | WPRIM | ID: wpr-27225

ABSTRACT

PURPOSE: MMP-2, 72 kDa-type IV collagenase, plays a major role in the migration and growth of tumor cells, a process that requires the disintegration of basement membrane. Activation of MMP-2 is correlated with the invasiveness of various tumors. The aim of this study was to determine the sequence-specific phosphorothioated oligodeoxynucleotides (ODNs) inhibiting the translation of MMP-2 mRNA and the subsequent invasiveness of tumor cells. MATERIALS AND METHODS: Eight types of antisense ODNs were designed and each (8micro gram/ml) were transfected into HT1080 cells. The effects of these antisense ODNs on MMP expression were examined by gelatin zymography, Western blot, Northern blot and matrigel assay. RESULTS: Antisense-5 (+904~923), antisense-6 (+1274~+1293) and antisense-7 (+1646~+1665) reduced the MMP-2 activity of the culture supernatant in HT1080 fibrosarcoma cells. Treatment with antisense-6 showed inhibition of MMP-2 mRNA and protein, and in vitro invasion in a dose-dependent manner. CONCLUSION: Antisense-6 might be one of the therapeutic candidates for tumor invasion and metastasis.


Subject(s)
Humans , Basement Membrane , Blotting, Northern , Blotting, Western , Collagenases , Fibrosarcoma , Gelatin , Matrix Metalloproteinase 2 , Neoplasm Metastasis , Oligodeoxyribonucleotides , RNA, Messenger
16.
Cancer Research and Treatment ; : 426-431, 2002.
Article in Korean | WPRIM | ID: wpr-199470

ABSTRACT

PURPOSE: The role of P38 mitogen-activated protein kinase (MAPK) in gastric cancer invasion has not yet been determined. In this study, we examined the effects of SB203580, a specific P38 MAPK inhibitor, on the in vitro invasion of gastric cancer and upon the molecules involved in this process. MATERIALS AND METHODS: Human gastric cancer SNU-638 cells were maintained in RPMI 1640 supplemented with 10% FBS. BIOCOAT matrigel invasion chambers were used to examine in vitro invasiveness, zymography for gelatinase activity, CAT assay for uPA promoter activity and Western and Northern blotting to determine protein and mRNA levels, respectively. RESULTS: Treatment of SNU-638 cells with SB203580, a specific P38 MAPK inhibitor, reduced in vitro invasiveness, dose-dependently. SB203580 treatment was found to decrease both mRNA expression and uPA promoter activity in gastric SNU-638 cells. In vitro invasion of SNU-638 cells was partially abrogated by uPA-neutralizing antibodies. The activities of MMPs were not significantly altered by SB203580. CONCLUSION: Our results suggest that P38 MAPK is a potential therapeutic target for inhibiting uPA-dependent gastric tumor invasiveness and metastasis.


Subject(s)
Animals , Cats , Humans , Antibodies , Blotting, Northern , Gelatinases , Matrix Metalloproteinases , Neoplasm Metastasis , p38 Mitogen-Activated Protein Kinases , Protein Kinases , RNA, Messenger , Stomach Neoplasms
17.
Experimental & Molecular Medicine ; : 221-226, 1998.
Article in English | WPRIM | ID: wpr-159766

ABSTRACT

Reactive oxygen species such as superoxides, hydrogen peroxide (H2O2) and hydroxyl radicals have been suggested to be involved in the catalytic action of nitric oxide synthase (NOS) to produce NO from L-arginine. An examination was conducted on the effects of oxygen radical scavengers and oxygen radical-generating systems on the activity of neuronal NOS and guanylate cyclase (GC) in rat brains and NOS from the activated murine macrophage cell line J774. Catalase and superoxide dismutase (SOD) showed no significant effects on NOS or GC activity. Nitroblue tetrazolium (NBT, known as a superoxide radical scavenger) and peroxidase (POD) inhibited NOS, but their inhibitory actions were removed by increasing the concentration of arginine or NADPH respectively, in the reaction mixture. NOS and NO-dependent GC were inactivated by ascorbate/FeSO4 (a metal-catalyzed oxidation system), 2'2'-azobis-amidinopropane (a peroxy radical producer), and xanthine/xanthine oxidase (a superoxide generating system). The effects of oxygen radicals or antioxidants on the two isoforms of NOS were almost similar. However, H2O2 activated GC in a dose-dependent manner from 100 microM to 1 mM without significant effects on NOS. H2O2-induced GC activation was blocked by catalase. These results suggested that oxygen radicals inhibited NOS and GC, but H2O2 could activate GC directly.


Subject(s)
Rats , Animals , Antioxidants/pharmacology , Brain/enzymology , Catalase/pharmacology , Cell Line , Guanylate Cyclase/metabolism , Hydrogen Peroxide/pharmacology , Macrophages/enzymology , NADP/pharmacology , Nitric Oxide Synthase/metabolism , Nitroblue Tetrazolium/pharmacology , Rats, Sprague-Dawley , Reactive Oxygen Species/metabolism , Signal Transduction , Superoxide Dismutase/pharmacology
18.
Experimental & Molecular Medicine ; : 171-175, 1997.
Article in English | WPRIM | ID: wpr-58968

ABSTRACT

Hemin blocked lipid peroxidations induced by either ascorbate/FeSO4, a metal-catalyzed oxidation system, or 2,2'-azobis-2-amidino-propane hydrochloride (ABAP) which produces peroxy radicals at constant rates. Hemin at very low micromolar concentrations strongly inhibited the ascorbate/FeSO4-induced peroxidation of rat liver phopholipids, soybean phosphatidylcholine and arachidonic acid, and this inhibition was also evident with the use of ABAP, although much higher concentrations of hemin were required than those for the inhibition of ascorbate/FeSO4-induced lipid peroxidation. However, hemoproteins such as hemoglobin, myoglobin and cytochrome C did not show any significant effect on this lipid peroxidation. Hemopexin and albumin abolished the inhibitory action of hemin. During incubation with ascorbate/FeSO4 or ABAP, hemin underwent a change in its absorption spectrum, resulting in a progressive decrease in the peak height of the characteristic absorption band at 385 nm. The above results suggest that hemin may act as an important antioxidant in vivo, protecting lipids from the peroxidative damage.


Subject(s)
Animals , Rats , Absorption , Arachidonic Acid , Cytochromes c , Hemin , Hemopexin , Lipid Peroxidation , Liver , Myoglobin , Phosphatidylcholines , Soybeans
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