17 results on '"C, Kaneda"'
Search Results
2. Melatonin stimulates glutathione peroxidase activity in human chorion
- Author
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Y, Okatani, A, Wakatsuki, K, Shinohara, C, Kaneda, and T, Fukaya
- Subjects
Glutathione Peroxidase ,Fetal Growth Retardation ,Superoxide Dismutase ,Abortion, Induced ,Chorion ,Free Radical Scavengers ,In Vitro Techniques ,Enzyme Activation ,Pre-Eclampsia ,Pregnancy ,Humans ,Female ,Lipid Peroxidation ,Melatonin - Abstract
In preeclampsia, placental production of lipid peroxides is abnormally increased, while placental glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities are decreased. Administration of melatonin, a powerful scavenger of oxygen free radicals, also may protect the placenta from free radical-induced damage by increasing the activity of antioxidant enzymes. To test this hypothesis we administered melatonin to pregnant women before they underwent voluntary interruption of pregnancy between 7 and 9 wk of gestation. Melatonin (6 mg) was administered orally at 12:00 hr, and samples of chorion and maternal blood were obtained at the time of the procedure, 1, 2 or 3 hr later. We measured the melatonin concentration in maternal serum and activities of GSH-Px and SOD and levels of melatonin in chorionic homogenates. Melatonin administration was reflected by markedly increased melatonin concentrations in maternal serum and in chorion, with peak levels achieved 1 hr after melatonin administration (serum, 46.87 +/- 10.87 nM/L; chorionic homogenate, 4.36 +/- 1.56 pmol/mg protein). Between 1 and 3 hr after melatonin administration, GSH-Px activity in chorionic homogenates increased significantly (P0.001), with peak levels occurring at 3 hr (51.68 +/- 3.22 mU/mg protein per min, 137.3% of GSH-Px activity in untreated control subjects). No significant changes in chorionic SOD activity occurred during the 3-hr post-administration period. These results indicate that exogenous melatonin increases GSH-Px activity in the chorion and thereby may protect indirectly against free radical injury. Melatonin could be useful in treating preeclampsia and possibly other clinical states involving excessive free radical production, such as intrauterine fetal growth retardation and fetal hypoxia.
- Published
- 2001
3. Melatonin protects fetal rat brain against oxidative mitochondrial damage
- Author
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A, Wakatsuki, Y, Okatani, K, Shinohara, N, Ikenoue, C, Kaneda, and T, Fukaya
- Subjects
Male ,Glutathione Peroxidase ,Xanthine Oxidase ,Free Radicals ,Superoxide Dismutase ,Brain ,Free Radical Scavengers ,Thiobarbituric Acid Reactive Substances ,Mitochondria ,Rats ,Adenosine Diphosphate ,Oxidative Stress ,Pregnancy ,Animals ,Female ,Lipid Peroxidation ,Rats, Wistar ,Melatonin - Abstract
Our objective was to investigate the effects of melatonin on the free radical-induced oxidative damage to mitochondria in fetal rat brain. Female Wistar rats on day 19 of pregnancy were used. Melatonin (10 mg/kg) or vehicle (control) was injected intraperitoneally 60 min prior to laparotomy for removal of the fetuses. The mitochondrial fraction was isolated from the fetal rat brain of each group. Superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were measured. As indicators of mitochondrial respiratory activity, we determined the respiratory control index (RCI) and the adenosine 5-diphosphate/oxygen (ADP/O) ratio in the presence and absence of 2.5 microM hypoxanthine and 0.02 units/mL xanthine oxidase. Mitochondrial lipid peroxidation was determined by measuring the concentration of thiobarbituric acid reactive substances in fetal brain mitochondria in the presence or absence of 2.5 microM hypoxanthine, 0.02 units/mL xanthine oxidase, and 50 microM FeSO4. The free radical-induced rates of inhibition of mitochondrial RCI and the ADP/O ratio were both significantly lower in the fetal rat brains treated with melatonin compared with those of the controls (RCI, 44.25 +/- 15.02% vs. 25.18 +/- 5.86%, P0.01; ADP/O ratio, 50.74 +/- 23.05% vs. 13.90 +/- 7.80%, P0.001). The mitochondrial lipid peroxidation induced by free radicals was significantly reduced in the melatonin-treated group compared with the controls (484.2 +/- 147.2%) vs. 337.6 +/- 61.0%, P0.01). Pretreatment with melatonin significantly increased the activity of GSH-Px (20.35 +/- 5.27 to 28.93 +/- 11.01 mU/min mg(-1) protein, P0.05) in fetal rat brain mitochondria, but the activity of SOD did not change significantly. Results indicate that the administration of melatonin to the pregnant rat may prevent the free radical-induced oxidative mitochondrial damage to fetal rat brain by a direct antioxidant effect and the activation of GSH-Px.
- Published
- 2001
4. Melatonin inhibits oxidative modification of low-density lipoprotein particles in normolipidemic post-menopausal women
- Author
-
A, Wakatsuki, Y, Okatani, N, Ikenoue, C, Izumiya, and C, Kaneda
- Subjects
Administration, Oral ,Free Radical Scavengers ,Middle Aged ,Thiobarbituric Acid Reactive Substances ,Lipoproteins, LDL ,Postmenopause ,Cholesterol ,Humans ,Female ,Oxidation-Reduction ,Triglycerides ,Aged ,Apolipoproteins B ,Melatonin - Abstract
In this study, we investigated the short-term effect of melatonin on the susceptibility of low-density lipoprotein (LDL) to oxidation in normolipidemic post-menopausal women. Fifteen post-menopausal women received 6.0 mg melatonin daily for 2 wk. Blood samples were obtained before and after the treatment and the plasma levels of total cholesterol, total triglyceride, high-density lipoprotein (HDL)-cholesterol, LDL-cholesterol, LDL-triglyceride, and LDL-apolipoprotein B were determined. LDL oxidation was performed by incubation with copper ions and was analyzed by monitoring the kinetics of conjugated diene formation and measuring the concentration of thiobarbituric-acid-reactive substances (TBARS). LDL-apolipoprotein B derivatization was analyzed by measuring trinitrobenzene sulfonic acid (TNBS) reactivity. Melatonin treatment significantly increased the plasma triglyceride levels (P0.05), but did not significantly alter the plasma levels of total cholesterol, HDL-cholesterol, or LDL-lipids. The kinetics analysis of conjugated diene production revealed that melatonin treatment significantly prolonged the lag time of conjugated diene formation (from 64.71+/-11.89 to 70.15+/-10.52 min, P0.05). The oxidation rate and the amount of conjugated diene, however, did not change significantly. The TBARS concentration was significantly reduced by melatonin treatment (from 49.31+/-7.57 to 38.69+/-23.90 nM/mg LDL, P0.05). Furthermore, melatonin treatment significantly reduced the copper-induced decrease of TNBS reactivity (from 79.43+/-6.19 to 86.50+/-9.07% at 1 hr and from 71.03+/-6.74 to 76.31+/-4.99% at 2 hr, P0.05). These results indicate that melatonin treatment may reduce LDL susceptibility to oxidative modification in normolipidemic post-menopausal women.
- Published
- 2000
5. Melatonin increases activities of glutathione peroxidase and superoxide dismutase in fetal rat brain
- Author
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Y, Okatani, A, Wakatsuki, and C, Kaneda
- Subjects
Rats, Sprague-Dawley ,Glutathione Peroxidase ,Fetus ,Pregnancy ,Superoxide Dismutase ,Animals ,Brain ,Female ,Free Radical Scavengers ,Fetal Blood ,Antioxidants ,Melatonin ,Rats - Abstract
Melatonin is a powerful scavenger of oxygen free radicals. In humans, melatonin is rapidly transferred from the maternal to the fetal circulation. To investigate whether or not maternal melatonin administration can protect the fetal rat brain from radical-induced damage by increasing the activities of antioxidant enzymes, we administered melatonin to pregnant rats on day 20 of gestation. Melatonin (10 mg/kg) was injected intraperitoneally at daytime (14:00 hr) and, to remove the fetuses, a laparotomy was performed at 1, 2, or 3 hr after its administration. We measured the melatonin concentration in the maternal serum and in fetal brain homogenates and determined the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in fetal brain homogenates. Melatonin administration markedly increased melatonin concentrations in the maternal serum and fetal brain homogenates, with peak levels achieved 1 hr after melatonin administration (serum: 538.2+/-160.7 pM/mL; brain homogenates: 13.8+/-2.8 pM/mg protein). Between 1 and 3 hr after melatonin administration, GSH-Px activity in fetal brain homogenates increased significantly (P0.01). Similarly, SOD activity increased significantly between 1 and 2 hr after melatonin administration (P0.01). These results indicate that melatonin administration to the mother increases antioxidant enzyme activities in the fetal brain and may thereby provide indirect protection against free radical injury. Thus, melatonin may potentially be useful in the treatment of neurodegenerative conditions that may involve excessive free radical production, such as fetal hypoxia and preeclampsia.
- Published
- 2000
6. Electrochemical synthesis of microporous polyaniline films using foam templates prepared by ultrasonication.
- Author
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Kaneda C, Sueyasu Y, Tanaka E, and Atobe M
- Abstract
We report a new soft template method for the synthesis of unique polyaniline (PANI) films with microporous structures. In this process, ultrasonication is used to foam an electrolyte solution containing a surfactant, which is subsequently employed as a soft template for PANI growth via the electrochemical polymerization of aniline. Analysis by scanning electron microscopy demonstrates that the resulting PANI films contain numerous micropores. These microporous PANI films exhibit faster charging (doping) and discharging (dedoping) current responses compared to ordinary flat films of the same material., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
7. Physical Activity and Body Mass Index in Relation to Infertility in Women.
- Author
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Kaneda C, Kanejima Y, Kitamura M, and Izawa KP
- Subjects
- Female, Humans, Infertility, Female physiopathology, Obesity physiopathology, Pregnancy, Pregnancy Rate trends, Body Mass Index, Exercise physiology, Infertility, Female etiology, Obesity complications
- Abstract
Background: Infertility is a global social issue, and reproductive health is a priority in global health. This review aimed to study the relation between physical activity (PA) and infertility in non-obese or non-overweight women., Methods: We used search strategies in the National Library of Medicine database including the PubMed database to October 2019 to find articles related to women and fertility, infertility, exercise, PA, pregnancy rate, live births, fecundability, and conception. Only cohort studies or randomized controlled trials in English were chosen for review that included outcomes directly related to becoming pregnant. We selected studies in which the participants were categorized by low or high body mass index (BMI)., Results: We found 6 papers meeting our criteria. In the association between PA and outcome, vigorous PA in women with low BMI resulted in both positive and negative effects that were weaker than those in women with high BMI. Among women with low BMI, moderate PA was weakly but positively associated with outcome whereas walking was not., Conclusion: We observed some trends and a slight difference between the outcomes of women with low versus high BMI. There are only a few studies on infertile women with low BMI, and further investigation is warranted., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)
- Published
- 2020
- Full Text
- View/download PDF
8. Black tea aroma inhibited increase of salivary chromogranin-A after arithmetic tasks.
- Author
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Yoto A, Fukui N, Kaneda C, Torita S, Goto K, Nanjo F, and Yokogoshi H
- Subjects
- Adult, Anxiety metabolism, Female, Humans, Male, Task Performance and Analysis, Visual Analog Scale, Young Adult, Affect drug effects, Chromogranin A analysis, Odorants analysis, Saliva chemistry, Stress, Psychological metabolism, Tea
- Abstract
Background: Growing attention has been paid to the effects of food flavor components on alleviating negative brain functions caused by stressful lifestyles. In this study, we investigated the alleviating effect of two kinds of black tea aromas on physical and psychological stress induced by the Uchida-Kraepelin test, based on salivary chromogranin-A (CgA) levels as a stress marker and subjective evaluations (Profile of Mood States)., Results: Compared with the water exposure control, inhaling black tea aroma (Darjeeling and Assam in this study) induced lower salivary CgA concentration levels after 30 min of mental stress load tasks. This anti-stress effect of black tea aroma did not differ between the two tea types even though the concentration of the anti-stress components in the Darjeeling tea aroma was higher than that in the Assam aroma. However, Darjeeling tea aroma tended to decrease the tension and/or anxiety score immediately after the first exposure., Conclusions: Inhaling black tea aroma may diminish stress levels caused by arithmetic mental stress tasks, and Darjeeling tea aroma tended to improve mood before mental stress load.
- Published
- 2018
- Full Text
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9. Transcription factor IRF8 plays a critical role in the development of murine basophils and mast cells.
- Author
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Sasaki H, Kurotaki D, Osato N, Sato H, Sasaki I, Koizumi S, Wang H, Kaneda C, Nishiyama A, Kaisho T, Aburatani H, Morse HC 3rd, Ozato K, and Tamura T
- Subjects
- Animals, Basophils metabolism, Cell Differentiation immunology, GATA2 Transcription Factor metabolism, Interferon Regulatory Factors metabolism, Mast Cells metabolism, Mice, Mice, Knockout, Stem Cells immunology, Stem Cells metabolism, Transcription Factors immunology, Transcription Factors metabolism, Basophils cytology, Basophils immunology, GATA2 Transcription Factor immunology, Interferon Regulatory Factors immunology, Mast Cells cytology, Mast Cells immunology
- Abstract
Basophils and mast cells play critical roles in host defense against pathogens and allergic disorders. However, the molecular mechanism by which these cells are generated is not completely understood. Here we demonstrate that interferon regulatory factor-8 (IRF8), a transcription factor essential for the development of several myeloid lineages, also regulates basophil and mast cell development. Irf8(-/-) mice displayed a severe reduction in basophil counts, which was accounted for by the absence of pre-basophil and mast cell progenitors (pre-BMPs). Although Irf8(-/-) mice retained peripheral tissue mast cells, remaining progenitors from Irf8(-/-) mice including granulocyte progenitors (GPs) were unable to efficiently generate either basophils or mast cells, indicating that IRF8 also contributes to the development of mast cells. IRF8 appeared to function at the GP stage, because IRF8 was expressed in GPs, but not in basophils, mast cells, and basophil/mast cell-restricted progenitor cells. Furthermore, we demonstrate that GATA2, a transcription factor known to promote basophil and mast cell differentiation, acts downstream of IRF8. These results shed light on the pathways and mechanism underlying the development of basophils and mast cells.
- Published
- 2015
- Full Text
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10. Human myo-inositol monophosphatase 2 rescues the nematode thermotaxis mutant ttx-7 more efficiently than IMPA1: functional and evolutionary considerations of the two mammalian myo-inositol monophosphatase genes.
- Author
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Ohnishi T, Tanizawa Y, Watanabe A, Nakamura T, Ohba H, Hirata H, Kaneda C, Iwayama Y, Arimoto T, Watanabe K, Mori I, and Yoshikawa T
- Subjects
- Animals, Behavior, Animal physiology, Blotting, Western, Caenorhabditis elegans genetics, Caenorhabditis elegans metabolism, Humans, In Situ Hybridization, Mice, Mice, Knockout, Transcriptome, Biological Evolution, Phosphoric Monoester Hydrolases genetics, Phosphoric Monoester Hydrolases metabolism, Phylogeny
- Abstract
Mammals express two myo-inositol monophosphatase (IMPase) genes, IMPA1/Impa1 and IMPA2/Impa2. In this study, we compared the spatial expression patterns of the two IMPase gene transcripts and proteins in mouse tissues. Results indicated discrete expression of the two IMPase genes and their protein products in various organs, including the brain. In Caenorhabditis elegans, loss of the IMPase gene, ttx-7, disrupts cellular polarity in RIA neurons, eliciting abnormal thermotaxis behavior. We performed a rescue experiment in mutant nematodes using mammalian IMPases. Human IMPA2 rescued the abnormal behavioral phenotype in the ttx-7 mutants more efficiently than IMPA1. These results raise a question about the phylogenetic origin of IMPases and the biological roles of mammalian IMPase 2 in mammals. Impa2 knockout mice generated in our laboratory, exhibited neither behavioral abnormalities nor a significant reduction in myo-inositol content in the brain and other examined tissues. Given the ability of human IMPA2 to rescue the ttx-7 mutant, and its genetic association with multiple neuropsychiatric disorders, close scrutiny of IMPA2 function and the evolutionary origin of IMPase genes is warranted., (© 2012 International Society for Neurochemistry.)
- Published
- 2013
- Full Text
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11. Melatonin stimulates glutathione peroxidase activity in human chorion.
- Author
-
Okatani Y, Wakatsuki A, Shinohara K, Kaneda C, and Fukaya T
- Subjects
- Abortion, Induced, Enzyme Activation drug effects, Female, Fetal Growth Retardation drug therapy, Fetal Growth Retardation etiology, Fetal Growth Retardation metabolism, Free Radical Scavengers pharmacology, Humans, In Vitro Techniques, Lipid Peroxidation drug effects, Pre-Eclampsia drug therapy, Pre-Eclampsia etiology, Pre-Eclampsia metabolism, Pregnancy, Superoxide Dismutase metabolism, Chorion drug effects, Chorion enzymology, Glutathione Peroxidase metabolism, Melatonin pharmacology
- Abstract
In preeclampsia, placental production of lipid peroxides is abnormally increased, while placental glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities are decreased. Administration of melatonin, a powerful scavenger of oxygen free radicals, also may protect the placenta from free radical-induced damage by increasing the activity of antioxidant enzymes. To test this hypothesis we administered melatonin to pregnant women before they underwent voluntary interruption of pregnancy between 7 and 9 wk of gestation. Melatonin (6 mg) was administered orally at 12:00 hr, and samples of chorion and maternal blood were obtained at the time of the procedure, 1, 2 or 3 hr later. We measured the melatonin concentration in maternal serum and activities of GSH-Px and SOD and levels of melatonin in chorionic homogenates. Melatonin administration was reflected by markedly increased melatonin concentrations in maternal serum and in chorion, with peak levels achieved 1 hr after melatonin administration (serum, 46.87 +/- 10.87 nM/L; chorionic homogenate, 4.36 +/- 1.56 pmol/mg protein). Between 1 and 3 hr after melatonin administration, GSH-Px activity in chorionic homogenates increased significantly (P < 0.001), with peak levels occurring at 3 hr (51.68 +/- 3.22 mU/mg protein per min, 137.3% of GSH-Px activity in untreated control subjects). No significant changes in chorionic SOD activity occurred during the 3-hr post-administration period. These results indicate that exogenous melatonin increases GSH-Px activity in the chorion and thereby may protect indirectly against free radical injury. Melatonin could be useful in treating preeclampsia and possibly other clinical states involving excessive free radical production, such as intrauterine fetal growth retardation and fetal hypoxia.
- Published
- 2001
- Full Text
- View/download PDF
12. Effects of short-term melatonin administration on lipoprotein metabolism in normolipidemic postmenopausal women.
- Author
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Wakatsuki A, Okatani Y, Ikenoue N, Kaneda C, and Fukaya T
- Subjects
- Apolipoproteins C blood, Apolipoproteins C drug effects, Cholesterol, VLDL blood, Cholesterol, VLDL drug effects, Female, Humans, Lipoprotein Lipase blood, Lipoprotein Lipase drug effects, Lipoproteins, VLDL blood, Middle Aged, Triglycerides blood, Antioxidants pharmacology, Lipoproteins, VLDL drug effects, Melatonin pharmacology, Postmenopause, Triglycerides metabolism
- Abstract
Objective: To investigate the effects of short-term administration of melatonin on lipoprotein metabolism in normolipidemic postmenopausal women., Methods: Fifteen such women received 6.0 mg melatonin daily for 2 weeks. Blood was sampled before and after treatment. We measured concentrations of total cholesterol and total triglyceride in the plasma, as well as the levels of cholesterol, triglyceride, and protein in the very low-density lipoprotein (VLDL), low-density lipoprotein (LDL), and high-density lipoprotein (HDL). Plasma apolipoprotein levels were determined by immunoturbidimetric assay. Activities of lipoprotein lipase, hepatic triglyceride lipase, and lecithin cholesterol acyltransferase were also determined by enzymatic analysis., Results: Melatonin administration significantly increased the plasma levels of triglyceride by 27.2% (P < 0.05), of VLDL-cholesterol by 37.2% (P < 0.01), of VLDL-triglyceride by 62.2% (P < 0.001), and of VLDL-protein by 30.0% (P < 0.05). However, the plasma total cholesterol level and the concentration of lipid and protein in LDL and HDL were not significantly affected. Melatonin significantly increased the plasma levels of apolipoprotein C-II by 29.5% (P < 0.005), of C-III by 17.1% (P < 0.001), and of E by 7.6% (P < 0.05). The plasma levels of apolipoprotein A-I, A-II, and B were not altered. Melatonin significantly inhibited the activity of lipoprotein lipase by -14.1% (P < 0.05), but did not significantly affect the activities of hepatic triglyceride lipase or of lecithin cholesterol acyltransferase., Conclusions: Findings indicate that melatonin increases the plasma level of VLDL particles by inhibiting the activity of lipoprotein lipase, but may not affect the plasma levels of LDL and HDL particles in postmenopausal women with normolipidemia.
- Published
- 2001
- Full Text
- View/download PDF
13. Melatonin protects fetal rat brain against oxidative mitochondrial damage.
- Author
-
Wakatsuki A, Okatani Y, Shinohara K, Ikenoue N, Kaneda C, and Fukaya T
- Subjects
- Adenosine Diphosphate metabolism, Animals, Brain metabolism, Female, Free Radicals toxicity, Glutathione Peroxidase metabolism, Lipid Peroxidation, Male, Mitochondria metabolism, Pregnancy, Rats, Rats, Wistar, Superoxide Dismutase metabolism, Thiobarbituric Acid Reactive Substances metabolism, Xanthine Oxidase toxicity, Brain drug effects, Free Radical Scavengers pharmacology, Melatonin pharmacology, Mitochondria drug effects, Oxidative Stress drug effects
- Abstract
Our objective was to investigate the effects of melatonin on the free radical-induced oxidative damage to mitochondria in fetal rat brain. Female Wistar rats on day 19 of pregnancy were used. Melatonin (10 mg/kg) or vehicle (control) was injected intraperitoneally 60 min prior to laparotomy for removal of the fetuses. The mitochondrial fraction was isolated from the fetal rat brain of each group. Superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were measured. As indicators of mitochondrial respiratory activity, we determined the respiratory control index (RCI) and the adenosine 5-diphosphate/oxygen (ADP/O) ratio in the presence and absence of 2.5 microM hypoxanthine and 0.02 units/mL xanthine oxidase. Mitochondrial lipid peroxidation was determined by measuring the concentration of thiobarbituric acid reactive substances in fetal brain mitochondria in the presence or absence of 2.5 microM hypoxanthine, 0.02 units/mL xanthine oxidase, and 50 microM FeSO4. The free radical-induced rates of inhibition of mitochondrial RCI and the ADP/O ratio were both significantly lower in the fetal rat brains treated with melatonin compared with those of the controls (RCI, 44.25 +/- 15.02% vs. 25.18 +/- 5.86%, P < 0.01; ADP/O ratio, 50.74 +/- 23.05% vs. 13.90 +/- 7.80%, P < 0.001). The mitochondrial lipid peroxidation induced by free radicals was significantly reduced in the melatonin-treated group compared with the controls (484.2 +/- 147.2%) vs. 337.6 +/- 61.0%, P < 0.01). Pretreatment with melatonin significantly increased the activity of GSH-Px (20.35 +/- 5.27 to 28.93 +/- 11.01 mU/min mg(-1) protein, P < 0.05) in fetal rat brain mitochondria, but the activity of SOD did not change significantly. Results indicate that the administration of melatonin to the pregnant rat may prevent the free radical-induced oxidative mitochondrial damage to fetal rat brain by a direct antioxidant effect and the activation of GSH-Px.
- Published
- 2001
- Full Text
- View/download PDF
14. Melatonin inhibits oxidative modification of low-density lipoprotein particles in normolipidemic post-menopausal women.
- Author
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Wakatsuki A, Okatani Y, Ikenoue N, Izumiya C, and Kaneda C
- Subjects
- Administration, Oral, Aged, Apolipoproteins B blood, Cholesterol blood, Female, Humans, Middle Aged, Oxidation-Reduction, Thiobarbituric Acid Reactive Substances, Triglycerides blood, Free Radical Scavengers pharmacology, Lipoproteins, LDL blood, Melatonin pharmacology, Postmenopause blood
- Abstract
In this study, we investigated the short-term effect of melatonin on the susceptibility of low-density lipoprotein (LDL) to oxidation in normolipidemic post-menopausal women. Fifteen post-menopausal women received 6.0 mg melatonin daily for 2 wk. Blood samples were obtained before and after the treatment and the plasma levels of total cholesterol, total triglyceride, high-density lipoprotein (HDL)-cholesterol, LDL-cholesterol, LDL-triglyceride, and LDL-apolipoprotein B were determined. LDL oxidation was performed by incubation with copper ions and was analyzed by monitoring the kinetics of conjugated diene formation and measuring the concentration of thiobarbituric-acid-reactive substances (TBARS). LDL-apolipoprotein B derivatization was analyzed by measuring trinitrobenzene sulfonic acid (TNBS) reactivity. Melatonin treatment significantly increased the plasma triglyceride levels (P<0.05), but did not significantly alter the plasma levels of total cholesterol, HDL-cholesterol, or LDL-lipids. The kinetics analysis of conjugated diene production revealed that melatonin treatment significantly prolonged the lag time of conjugated diene formation (from 64.71+/-11.89 to 70.15+/-10.52 min, P<0.05). The oxidation rate and the amount of conjugated diene, however, did not change significantly. The TBARS concentration was significantly reduced by melatonin treatment (from 49.31+/-7.57 to 38.69+/-23.90 nM/mg LDL, P<0.05). Furthermore, melatonin treatment significantly reduced the copper-induced decrease of TNBS reactivity (from 79.43+/-6.19 to 86.50+/-9.07% at 1 hr and from 71.03+/-6.74 to 76.31+/-4.99% at 2 hr, P<0.05). These results indicate that melatonin treatment may reduce LDL susceptibility to oxidative modification in normolipidemic post-menopausal women.
- Published
- 2000
- Full Text
- View/download PDF
15. Melatonin increases activities of glutathione peroxidase and superoxide dismutase in fetal rat brain.
- Author
-
Okatani Y, Wakatsuki A, and Kaneda C
- Subjects
- Animals, Brain enzymology, Female, Fetal Blood metabolism, Fetus, Free Radical Scavengers blood, Melatonin blood, Pregnancy, Rats, Rats, Sprague-Dawley, Antioxidants pharmacology, Brain drug effects, Free Radical Scavengers pharmacology, Glutathione Peroxidase metabolism, Melatonin pharmacology, Superoxide Dismutase metabolism
- Abstract
Melatonin is a powerful scavenger of oxygen free radicals. In humans, melatonin is rapidly transferred from the maternal to the fetal circulation. To investigate whether or not maternal melatonin administration can protect the fetal rat brain from radical-induced damage by increasing the activities of antioxidant enzymes, we administered melatonin to pregnant rats on day 20 of gestation. Melatonin (10 mg/kg) was injected intraperitoneally at daytime (14:00 hr) and, to remove the fetuses, a laparotomy was performed at 1, 2, or 3 hr after its administration. We measured the melatonin concentration in the maternal serum and in fetal brain homogenates and determined the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in fetal brain homogenates. Melatonin administration markedly increased melatonin concentrations in the maternal serum and fetal brain homogenates, with peak levels achieved 1 hr after melatonin administration (serum: 538.2+/-160.7 pM/mL; brain homogenates: 13.8+/-2.8 pM/mg protein). Between 1 and 3 hr after melatonin administration, GSH-Px activity in fetal brain homogenates increased significantly (P<0.01). Similarly, SOD activity increased significantly between 1 and 2 hr after melatonin administration (P<0.01). These results indicate that melatonin administration to the mother increases antioxidant enzyme activities in the fetal brain and may thereby provide indirect protection against free radical injury. Thus, melatonin may potentially be useful in the treatment of neurodegenerative conditions that may involve excessive free radical production, such as fetal hypoxia and preeclampsia.
- Published
- 2000
- Full Text
- View/download PDF
16. Subcellular localization of protein phosphatase type 1 isotypes in mouse osteoblastic cells.
- Author
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Haneji T, Morimoto H, Morimoto Y, Shirakawa S, Kobayashi S, Kaneda C, Shima H, and Nagao M
- Subjects
- Amino Acid Sequence, Animals, Antibodies, Blotting, Western, Cell Line, Cell Nucleolus enzymology, Cell Nucleus enzymology, Immunohistochemistry, Isoenzymes analysis, Mice, Molecular Sequence Data, Osteoblasts ultrastructure, Phosphoprotein Phosphatases immunology, Subcellular Fractions enzymology, Osteoblasts enzymology, Phosphoprotein Phosphatases analysis
- Abstract
The cytolocalization of protein phosphatase type 1 catalytic subunits in exponentially growing mouse osteoblastic MC3T3-E1 cells was determined. Formaldehyde-fixed and alcohol-permeabilized cultured cells were reacted with the PP1 alpha, PP1 delta, PP1 gamma 1, and PP1 gamma 2 antibodies using immunohistochemical methods. With PP1 alpha antibody intense staining occurred in the nuclei, while with PP1 delta antibody nucleolus-like bodies were intensely stained. PP1 gamma 1 localized in the perinuclear region and in the nucleus of the cultured cells, with the staining reaction of the former being much stronger than that in the latter. An immunoreaction did not occur in the cells interacted with PP1 gamma 2 antibody or with the normal rabbit serum. Proteins were prepared from the exponentially growing cells and subconfluent cells. Cellular fractionation was also done with the exponentially growing cells and proteins were prepared from each fraction. Each protein preparation was subjected to SDS-PAGE followed by Western blot analysis with the antibodies. PP1 alpha recognized the 38 kDa proteins mainly present in the nucleus, whereas PP1 delta interacted with the proteins in the nucleolar fraction whose molecular weight was estimated as 37 kDa. PP1 gamma 1 antibody recognized a band corresponding to an estimated molecular weight of 36 kDa mainly in the cytosolic fraction. PP1 gamma 2 antibody and the normal rabbit serum did not interact with any proteins prepared from the cultured cells. Our observations show that four different isozymes of protein phosphatases occupy distinct compartments in MC3T3-E1 cells. This differential distribution suggests that these isozymes may play different roles in cellular functions.
- Published
- 1998
- Full Text
- View/download PDF
17. Overexpression of mitochondrial genes in alloplasmic common wheat with a cytoplasm of wheatgrass (Agropyron trichophorum) showing depressed vigor and male sterility.
- Author
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Suzuki T, Nakamura C, Mori N, and Kaneda C
- Subjects
- Amanitins pharmacology, DNA, Mitochondrial analysis, DNA, Plant analysis, Fertility genetics, Genes, Plant genetics, Heparin pharmacology, Poaceae physiology, RNA analysis, RNA Polymerase II antagonists & inhibitors, RNA, Mitochondrial, RNA, Plant analysis, Transcription, Genetic drug effects, Triticum physiology, Gene Expression Regulation, Plant, Mitochondria genetics, Poaceae genetics, Triticum genetics
- Abstract
An alloplasmic hybrid (nucleus-cytoplasm hybrid) of common wheat (Triticum aestivum) with a cytoplasm of wheatgrass (Agropyron trichophorum) shows highly depressed vigor and complete male sterility. The presence of one short-arm telocentric homeologous group 1 chromosome (telosome) of the cytoplasm donor, however, restores normal vigor and male fertility of the hybrid. To study role(s) of the telosome on vigor/fertility restoration, mitochondrial genome organization and gene expression were compared among seedlings of the alloplasmic line showing depressed vigor, the corresponding restored line having a pair of the telosomes, and a euplasmic nuclear donor as control. No differences were detected in the mitochondrial genome structure between the depressed line and the restored line. Northern blot analysis using ten mitochondrial genes as probes showed no differences in transcript size and number between the depressed and restored lines, although clear differences were found in size of the major transcripts of two genes (cob and orf25) between the alloplasmic lines and the euplasmic control. Steady-state transcript levels were higher in the depressed line than in the other lines for all the mitochondrial genes analyzed including rrn18&5 when the same amount of mitochondrial RNA was loaded. The amount of rrn18&5 transcript in the total cellular RNA, however, did not differ among the lines. Run-on transcription analysis demonstrated markedly elevated transcriptional activities of all the mitochondrial genes analyzed in the depressed line based on unit amount of mitochondrial DNA, RNA and protein. The presence of Agropyron telosomes apparently normalized the level of mitochondrial transcription. These observations suggest either direct or indirect association of the observed mitochondrial gene overexpression with the depressed vigor and male sterility of the alloplasmic hybrid.
- Published
- 1995
- Full Text
- View/download PDF
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