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Wang Z, Zhang J, Liu H, Huang H, Wang C, Shen Y, Li D, Jing H. Melatonin, a potent regulator of hemeoxygenase-1, reduces cardiopulmonary bypass-induced renal damage in rats. J Pineal Res 2009; 46:248-54. [PMID: 19317793 DOI: 10.1111/j.1600-079x.2008.00624.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Acute renal dysfunction is a frequent complication after cardiac surgery with cardiopulmonary bypass (CPB). This study was designed to evaluate the potential protective effect of melatonin on CPB-induced renal damage in a rat model. Forty male Sprague-Dawley rats were randomly divided into four groups: sham, control (CPB + placebo), low dose of melatonin (CPB + 10 mg/kg melatonin) and high dose of melatonin (CPB + 20 mg/kg melatonin). Blood samples were collected at the beginning, at the end of CPB, and at 0.5, 1, 2, 3, and 24 hr postoperation. Serum creatinine and blood urea nitrogen levels were assayed. Rats were killed 24 hr after surgery, the histologic appearance of the kidney and malondialdehyde (MDA), myeloperoxidase (MPO), catalase (CAT) and superoxide dismutase (SOD) contents were determined. The expression levels of hemeoxygenase-1 (HO-1) protein and gene were determined using western blotting and real-time PCR, respectively. In the control group, CPB surgery significantly increased urea, creatinine levels in serum, MDA and MPO levels in tissues, while decreasing SOD and CAT activities in tissues. Histopathologic findings of the control group confirmed that there was renal impairment by cast formation and tubular necrosis in the tubular epithelium. These changes were markedly reversed in both low dose of melatonin and high dose of melatonin groups. Furthermore, HO-1 gene transcript and protein were significantly upregulated in the kidney tissues after melatonin treatment compared with the placebo treatment. Our findings show that melatonin was effective in preventing CPB-induced renal damage probably through its antioxidant function and upregulation of HO-1.
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Affiliation(s)
- Zhongqiu Wang
- Department of Cardiothoracic Surgery, Jinling Hospital, Clinical Medicine School of Nanjing University, Nanjing, China
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Gitto E, Pellegrino S, Gitto P, Barberi I, Reiter RJ. Oxidative stress of the newborn in the pre- and postnatal period and the clinical utility of melatonin. J Pineal Res 2009; 46:128-39. [PMID: 19054296 DOI: 10.1111/j.1600-079x.2008.00649.x] [Citation(s) in RCA: 210] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Newborns, and especially those delivered preterm, are probably more prone to oxidative stress than individuals later in life. Also during pregnancy, increased oxygen demand augments the rate of production of reactive oxygen species (ROS) and women, even with normal pregnancies, experience elevated oxidative stress and lipid peroxidation compared with nonpregnant women. Also, there appears to be an increase in ROS generation in the placenta of pre-eclamptic women. In comparison with healthy adults, newborn infants have lower levels of plasma antioxidants such as vitamin E, beta-carotene, and sulphydryl groups, lower levels of plasma metal binding proteins including ceruloplasmin and transferrin, and reduced activity of erythrocyte superoxide dismutase. This review summarizes conditions of newborns where there is elevated oxidative stress. Included in this group of conditions is asphyxia, respiratory distress syndrome and sepsis and the review also summarizes the literature related to clinical trials of antioxidant therapies and of melatonin, a highly effective antioxidant and free radical scavenger. The authors document there is general agreement that short-term melatonin therapy may be highly effective and that it has a remarkably benign safety profile, even when neonates are treated with pharmacological doses. Significant complications with long-term melatonin therapy in children and adults also have not been reported. None of the animal studies of maternal melatonin treatment or in postnatal life have shown any treatment-related side effects. The authors conclude that treatment with melatonin might result in a wide range of health benefits, improved quality of life and reduced healthcare costs and may help reduce complications in the neonatal period.
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Affiliation(s)
- Eloisa Gitto
- Neonatal Intensive Care Unit, Institute of Medical Pediatrics, University of Messina, Messina, Italy
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Abstract
Singlet oxygen was generated by means of rose bengal under irradiation by visible light. N(1)-acetyl-5-methoxykynuramine (AMK) was rapidly destroyed by this reactive oxygen species, whereas its formylated precursor, N(1)-acetyl-N(2)-formyl-5-methoxykynuramine (AFMK), was remarkably inert. At photon fluence rates of 1400 mumol photons/m(2)s, and using 20 mum rose bengal, most of initially 0.2 mm AMK was destroyed within 2 min, whereas AFMK remained practically unchanged for much longer periods of time. Competition experiments with other scavengers revealed the following order of reactivity towards singlet oxygen: diazabicyclo-[2,2,2]-octane (DABCO) << imidazole < 4-ethylphenol < N(alpha)-acetylhistidine < histidine < melatonin < AMK, the last one being about 150 times more effective than DABCO. Contrary to the oxidation in free radical-generating systems, AMK did not form adducts with the tyrosine side chain fragment, 4-ethylphenol, under the influence of singlet oxygen. In UV-exposed cells (keratinocytes, plant cells) it is likely to be more rapidly destroyed by singlet oxygen than formed from AFMK.
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Affiliation(s)
- Meike Schaefer
- Johann Friedrich Blumenbach Institute of Zoology and Anthropology, University of Göttingen, Göttingen, Germany
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Esposito E, Genovese T, Caminiti R, Bramanti P, Meli R, Cuzzocrea S. Melatonin reduces stress-activated/mitogen-activated protein kinases in spinal cord injury. J Pineal Res 2009; 46:79-86. [PMID: 19090911 DOI: 10.1111/j.1600-079x.2008.00633.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Permanent functional deficits following spinal cord injury (SCI) arise from both mechanical injury and from secondary tissue reactions involving inflammation. The mitogen-activated protein kinases (MAPKs) play a critical role in cell signaling and gene expression. MAPK family includes three major members: extracellular signal regulated kinase (ERK), p38, and c-Jun N-terminal kinase (JNK), representing three different signaling cascades. Moreover, various studies have clearly shown that high-mobility group box 1 (HMGB1) protein is implicated as a putative danger signal involved in the pathogenesis of a variety of inflammatory conditions including autoimmunity, cancer, trauma and hemorrhagic shock, and ischemia-reperfusion injury. Recently, we have reported that the pineal secretory product melatonin exerts important anti-inflammatory effects in an experimental model of SCI induced by the application of vascular clips (force of 24 g) to the dura after a four-level T5-T8 laminectomy. However, no reports are available on the effect of melatonin on MAPK signaling pathways and HMGB1 expression in SCI. The aim of the present study was to evaluate whether the melatonin protective effect observed in SCI is related to the regulation of MAPK signaling pathways and HMGB1 in mice. In this study we demonstrate the efficacy of treatment with the melatonin in SCI in mice in reducing (a) motor recovery, (b) activation of MAPKs p38, JNK and ERK1/2, (c) tumor necrosis factor-alpha expression, and (d) expression of HMGB1. We propose that melatonin's ability to reduce SCI in mice is also related to a reduction in MAPK signaling pathways and HMGB1 expression.
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Affiliation(s)
- Emanuela Esposito
- Department of Experimental Pharmacology, University of Naples "Federico II", Napoli, Italy
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55
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Abstract
In this study, the effect of melatonin on sodium arsenite (arsenite)-induced peripheral neurotoxicity was investigated using dorsal root ganglion (DRG) explants. After 24-hr incubation, arsenite (30 microm) consistently elevated the expression of heat shock protein 70 and haeme oxygenase-1, two well-known stress proteins, in the treated DRG explants. Co-incubation with melatonin (4 and 20 mm) concentration-dependently attenuated arsenite-induced elevation in stress proteins. Furthermore, melatonin inhibited arsenite-induced phosphorylation of p38 and DNA fragmentation. Inhibition by melatonin of arsenite-induced apoptosis was mediated via inactivating both endoplasmic reticulum (ER) and mitochondrial pathways. In the ER pathway, melatonin suppressed arsenite-induced elevation in activating transcription factor-6 and CCAAT/enhancer-binding protein homologous protein in the nuclear fraction of the treated DRG explants. Moreover, melatonin attenuated arsenite-induced activation of caspase 12, an ER-specific enzyme. In the mitochondrial pathway, arsenite-induced increases in Bcl-2 levels and cytosolic cytochrome c were reduced by melatonin. At the same time, melatonin inhibited arsenite-induced activation of caspase 3 in the treated DRG explants. Compared with glutathione and N-acetyl cysteine, melatonin was more potent than either in inhibiting arsenite-induced elevation in stress proteins. Taken together, our study demonstrates that melatonin is protective against arsenite-induced neurotoxicity in DRG explants. In addition, melatonin prevented arsenite-induced apoptosis via suppression of ER and mitochondrial activation. Our data suggest that melatonin is potentially a therapy for arsenite-induced peripheral neuropathy.
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Affiliation(s)
- Anya M Y Lin
- Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan.
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Lee YD, Kim JY, Lee KH, Kwak YJ, Lee SK, Kim OS, Song DY, Lee JH, Baik TK, Kim BJ, Kim JY, Baik HW. Melatonin attenuates lipopolysaccharide-induced acute lung inflammation in sleep-deprived mice. J Pineal Res 2009; 46:53-7. [PMID: 18673421 DOI: 10.1111/j.1600-079x.2008.00621.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Sleep disorders are great problems in modern society. Even minimal changes of sleep can affect health. Especially, patients with pulmonary diseases complain of sleep problems such as sleep disturbance and insomnia. Recent studies have shown an association between sleep deprivation (SD) and inflammation, however, the underlying mechanisms remain unclear. In the present study, we investigated whether melatonin protects against acute lung inflammation in SD. Male ICR mice were deprived sleep using modified multiplatform water bath for 3 days. Acute lung inflammation was induced by lipopolysaccharide (LPS; 5 mg/kg). Melatonin (5 mg/kg) and LPS was administered in SD mice at day 2. Mice were divided into five groups as control, SD, LPS, LPS + SD, and LPS + SD + melatonin (each group, n = 11). Mice were killed on day 3 after treatment of melatonin and LPS for 24 hr. Lung tissues were collected for histological examination and protein analysis. The malondialdehyde (MDA) level was determined for the effect of oxidative stress. Melatonin restored weight loss in LPS + SD. Histological findings revealed alveolar damages with inflammatory cell infiltration in LPS + SD. Melatonin remarkably attenuated the alveolar damages. In western blot analysis, LPS reduced the levels of Bcl-XL and procaspase-3 in SD mice. After treatment with melatonin, the levels of Bcl-XL and procaspase-3 increased when compared with LPS + SD. LPS treatment showed an increase of TUNEL-positive cells, whereas melatonin prevented the increase of cell death in LPS + SD animals. In lipid peroxidation assay, melatonin significantly reduced the elevated MDA level in LPS + SD. Our results suggest that melatonin attenuates acute lung inflammation during SD via anti-apoptotic and anti-oxidative actions.
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Affiliation(s)
- Yang-Deok Lee
- Department of Internal Medicine, Eulji University School of Medicine, Daejeon, Republic of Korea
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Backhaus C, Rahman H, Scheffler S, Laatsch H, Hardeland R. NO scavenging by 3-hydroxyanthranilic acid and 3-hydroxykynurenine: N-nitrosation leads via oxadiazoles to o-quinone diazides. Nitric Oxide 2008; 19:237-44. [DOI: 10.1016/j.niox.2008.07.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2007] [Revised: 06/21/2008] [Accepted: 07/09/2008] [Indexed: 11/28/2022]
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58
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Henshaw DL, Ward JP, Matthews JC. Can disturbances in the atmospheric electric field created by powerline corona ions disrupt melatonin production in the pineal gland? J Pineal Res 2008; 45:341-50. [PMID: 18384531 DOI: 10.1111/j.1600-079x.2008.00594.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recent epidemiological studies have reported an increased risk of leukemia in adults and children near overhead high voltage powerlines at distances beyond the measured range of the direct electric and magnetic fields. Corona ions are emitted by powerlines, forming a plume that is carried away from the line by the wind. The plume generates highly variable disturbances in the atmospheric electric field of tens to a few hundred V/m on time scales from seconds to minutes. Such disturbances can be seen up to several hundred meters from powerlines. It is hypothesized that these random disturbances result in the disruption of nocturnal melatonin synthesis and related circadian rhythms, in turn leading to increased risk of a number of adverse health effects including leukemia. In support of the hypothesis, it is noted that melatonin is highly protective of oxidative damage to the human hemopoietic system. A review of electric field studies provides evidence that (i) diurnal variation in the natural atmospheric electric field may itself act as a weak Zeitgeber; (ii) melatonin disruption by electric fields occurs in rats; (iii) in humans, disturbances in circadian rhythms have been observed with artificial fields as low at 2.5 V/m. Specific suggestions are made to test the aspects of the hypothesis.
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Affiliation(s)
- Denis L Henshaw
- H H Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, UK.
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59
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Nagai R, Watanabe K, Wakatsuki A, Hamada F, Shinohara K, Hayashi Y, Imamura R, Fukaya T. Melatonin preserves fetal growth in rats by protecting against ischemia/reperfusion-induced oxidative/nitrosative mitochondrial damage in the placenta. J Pineal Res 2008; 45:271-6. [PMID: 18373555 DOI: 10.1111/j.1600-079x.2008.00586.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
We have previously demonstrated that melatonin protects against ischemia/reperfusion-induced oxidative damage to mitochondria in the fetal rat brain. The purpose of the present study was to evaluate the effects of maternally administered melatonin on ischemia/reperfusion-induced oxidative placental damage and fetal growth restriction in rats. The utero-ovarian arteries were occluded bilaterally for 30 min in rats on day 16 of pregnancy to induce fetal ischemia. Reperfusion was achieved by releasing the occlusion and restoring circulation. Melatonin solution (20 microg/mL) or the vehicle alone was administered orally during pregnancy. A sham operation was performed in control rats, which were treated with vehicle alone. Laparotomy was performed on day 20 of pregnancy and the number and weight of fetal rats and placentas were measured. Placental mitochondrial respiratory control index (RCI), a marker of mitochondrial respiratory activity, was also calculated for each group. Using immunohistochemistry, we investigated the degree of immunostaining of 8-hydroxy-2-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage, and redox factor-1(ref-1), which repairs DNA damage and acts as a redox-modifying factor in rat placenta. Predictably, the ischemia/reperfusion operation significantly decreased the weight of fetal rats and placentas and the RCI. Melatonin prevented ischemia/reperfusion-induced changes in RCI (1.55 +/- 0.05 to 1.83 +/- 0.09, P < 0.05) and fetal growth (3.04 +/- 0.17 to 3.90 +/- 0.1, P < 0.0001). Immunohistochemistry revealed significant positive staining for 8-OHdG and ref-1 following ischemia/reperfusion; these effects were also reduced by melatonin treatment. Results indicated that ischemia/reperfusion-induced oxidative placental DNA and mitochondrial damage and fetal growth restriction can be prevented by maternally administered melatonin.
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Affiliation(s)
- Ryuhei Nagai
- Department of Obstetrics and Gynecology, Kochi Medical School, Kochi, Japan
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60
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Santello FH, Frare EO, dos Santos CD, Caetano LC, Alonso Toldo MP, do Prado JC. Suppressive action of melatonin on the TH-2 immune response in rats infected with Trypanosoma cruzi. J Pineal Res 2008; 45:291-6. [PMID: 18373553 DOI: 10.1111/j.1600-079x.2008.00589.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Control of the acute phase of Trypanosoma cruzi infection is critically dependent on cytokine-mediated macrophage activation to intracellular killing, natural killer (NK) cells, CD4(+) T cells, CD8(+) T cells and B cells. Cell-mediated immunity in T. cruzi infection is also modulated by cytokines, but in addition to parasite-specific responses, autoimmunity can be also triggered. Importantly, cytokines may also play a role in the cell-mediated immunity of infected subjects. Here we studied the role of cytokines in the regulation of innate and adaptive immunity during the acute phase of T. cruzi infection in Wistar rats. Melatonin is an effective regulator of the immune system. Macrophages and T lymphocytes, which have melatonin receptors, are target cells for the immunomodulatory function of melatonin. In this paper melatonin was orally given via two protocols: prior to and concomitant with infection. Both treatments were highly effective against T. cruzi with enhanced action for the concomitant treatment. The data suggest an up-regulation of the TH-1 immune response as all analyzed parameters, interleukin (IL)-4, IL-10, transforming growth factor-beta1 and splenocyte proliferation, displayed reduced levels as compared with the untreated counterparts. However, the direct effects of melatonin on immune cells have not been fully investigated during T. cruzi infection. We conclude that in light of the current results, melatonin exerted important therapeutic benefits through its immune regulatory effects.
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Affiliation(s)
- Fabricia Helena Santello
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Brasil.
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61
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Zhu HQ, Cheng XW, Xiao LL, Jiang ZK, Zhou Q, Gui SY, Wei W, Wang Y. Melatonin prevents oxidized low-density lipoprotein-induced increase of myosin light chain kinase activation and expression in HUVEC through ERK/MAPK signal transduction. J Pineal Res 2008; 45:328-34. [PMID: 18435720 DOI: 10.1111/j.1600-079x.2008.00595.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Melatonin, the main secretary product of the pineal gland, is potentially effective in the prevention of a number of diseases in which free radical processes are involved. The development of hypercholesterolemia is a multifactorial process in which elevated oxidized low-density lipoprotein (ox-LDL) levels play a central role. The purpose of this study was to test whether melatonin prevents ox-LDL-induced increase of myosin light chain kinase (MLCK) activation and expression in human umbilical vein endothelial cells (HUVECs) through extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) signal transduction. HUVEC were cultured in vitro and treated with ox-LDL, melatonin, and PD98059 (a selective inhibitor of ERK), respectively. The expression, transcription, and activity of MLCK were measured by western blot, immunohistochemistry, reverse transcription-polymerase chain reaction and gamma-(32)P-adenosine triphosphate (ATP) incorporation, respectively. The results showed that the expression and activity of MLCK were increased in ox-LDL-treated HUVECs and this was decreased by melatonin and PD98059. The expression and activity of MLCK induced by ox-LDL was associated with the phosphorylation of ERK. These results indicate for the first time that hypercholesterolemia may be associated with MLCK expression and the activity which can be reduced by melatonin through ERK/MAPK signal transduction.
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Affiliation(s)
- Hua-Qing Zhu
- Laboratory of Molecular Biology and Department of Biochemistry, Anhui Medical University, Ministry of Education and Anhui Province, Anhui, China
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62
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Kedziora-Kornatowska K, Szewczyk-Golec K, Czuczejko J, Pawluk H, van Marke de Lumen K, Kozakiewicz M, Bartosz G, Kedziora J. Antioxidative effects of melatonin administration in elderly primary essential hypertension patients. J Pineal Res 2008; 45:312-7. [PMID: 18363674 DOI: 10.1111/j.1600-079x.2008.00592.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The imbalance of the redox state of the aging organism may be involved in the development of primary essential hypertension. Melatonin, a potent antioxidant agent, was found to exert a hypotensive effect and improve the function of the cardiovascular system. The aim of this study was to determine the influence of melatonin supplementation on oxidative stress parameters in elderly primary essential hypertensive (EH) patients, controlled by a diuretic (indapamide) monotherapy. The levels of malondialdehyde (MDA) and reduced glutathione (GSH), activities of Cu-Zn superoxide dismutase (SOD-1), catalase (CAT) and glutathione peroxidase (GSH-Px) in erythrocytes, the plasma level of nitrate/nitrite, the content of carbonyl groups of plasma proteins and morning melatonin levels in the serum of 17 elderly EH patients were determined at the baseline and after the 15th and 30th days of melatonin supplementation (5 mg daily). Melatonin administration resulted in a significant increase in the morning melatonin concentration, SOD-1 and CAT activities, and a reduction in the MDA level. Statistically significant alterations in the levels of GSH, nitrate/nitrite and carbonyl groups and the activity of GSH-Px were not observed. These results indicate an improvement in the antioxidative defense of the organism by melatonin supplementation in the examined group and may suggest melatonin supplementation as an additional treatment supporting hypotensive therapy in elderly EH patients.
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63
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Ortiz GG, Benítez-King GA, Rosales-Corral SA, Pacheco-Moisés FP, Velázquez-Brizuela IE. Cellular and biochemical actions of melatonin which protect against free radicals: role in neurodegenerative disorders. Curr Neuropharmacol 2008; 6:203-14. [PMID: 19506721 PMCID: PMC2687933 DOI: 10.2174/157015908785777201] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2007] [Revised: 01/01/2008] [Accepted: 02/19/2008] [Indexed: 01/21/2023] Open
Abstract
Molecular oxygen is toxic for anaerobic organisms but it is also obvious that oxygen is poisonous to aerobic organisms as well, since oxygen plays an essential role for inducing molecular damage. Molecular oxygen is a triplet radical in its ground-stage (.O-O.) and has two unpaired electrons that can undergoes consecutive reductions of one electron and generates other more reactive forms of oxygen known as free radicals and reactive oxygen species. These reactants (including superoxide radicals, hydroxyl radicals) possess variable degrees of toxicity. Nitric oxide (NO*) contains one unpaired electron and is, therefore, a radical. NO* is generated in biological tissues by specific nitric oxide synthases and acts as an important biological signal. Excessive nitric oxide production, under pathological conditions, leads to detrimental effects of this molecule on tissues, which can be attributed to its diffusion-limited reaction with superoxide to form the powerful and toxic oxidant, peroxynitrite.Reactive oxygen and nitrogen species are molecular "renegades"; these highly unstable products tend to react rapidly with adjacent molecules, donating, abstracting, or even sharing their outer orbital electron(s). This reaction not only changes the target molecule, but often passes the unpaired electron along to the target, generating a second free radical, which can then go on to react with a new target amplifying their effects.This review describes the mechanisms of oxidative damage and its relationship with the most highly studied neurodegenerative diseases and the roles of melatonin as free radical scavenger and neurocytoskeletal protector.
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Affiliation(s)
- Genaro G Ortiz
- Laboratorio de Desarrollo-Envejecimiento, Enfermedades Neurodegenerativas, División de Neurociencias, Centro de Investigación Biomédica de Occidente (CIBO), Instituto Mexicano del Seguro Social, IMSS, Sierra Mojada 800 C.P. 44340 Guadalajara, Jalisco, México.
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64
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Das A, Belagodu A, Reiter RJ, Ray SK, Banik NL. Cytoprotective effects of melatonin on C6 astroglial cells exposed to glutamate excitotoxicity and oxidative stress. J Pineal Res 2008; 45:117-24. [PMID: 18373557 PMCID: PMC2632944 DOI: 10.1111/j.1600-079x.2008.00582.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
To preserve the central nervous system (CNS) function after a traumatic injury, therapeutic agents must be administered to protect neurons as well as glial cells. Cell death in CNS injuries and diseases are attributed to many factors including glutamate toxicity and oxidative stress. We examined whether melatonin, a potent anti-oxidant and free radical scavenger, would attenuate apoptotic death of rat C6 astroglial cells under glutamate excitotoxicity and oxidative stress. Exposure of C6 cells to 500 microM L-glutamic acid (LGA) and 100 microm hydrogen peroxide (H(2)O(2)) for 24 hr caused significant increases in apoptosis. Apoptosis was evaluated by Wright staining and ApopTag assay. Melatonin receptor 1 appeared to be involved in the protection of these cells from excitotoxic and oxidative damage. Cells undergoing excitotoxic and oxidative stress for 15 min were then treated with 150 nM melatonin, which prevented Ca(2+)influx and cell death. Western blot analyses showed alterations in Bax and Bcl-2 expression resulting in increased Bax:Bcl-2 ratio during apoptosis. Western blot analyses also showed increases in calpain and caspase-3 activities, which cleaved 270 kD alpha-spectrin at specific sites to generate 145 kD spectrin breakdown product (SBDP) and 120 kD SBDP, respectively. However, 15-min post-treatment of C6 cells with melatonin dramatically reduced Bax:Bcl-2 ratio and proteolytic activities, decreasing LGA or H(2)O(2)-induced apoptosis. Our data showed that melatonin prevented proteolysis and apoptosis in C6 astroglial cells. The results suggest that melatonin may be an effective cytoprotective agent against glutamate excitotoxicity and oxidative stress in CNS injuries and diseases.
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MESH Headings
- Animals
- Antioxidants/pharmacology
- Apoptosis/drug effects
- Astrocytes/metabolism
- Astrocytes/pathology
- Blotting, Western
- Calcium/metabolism
- Cell Line, Tumor
- Cell Survival/drug effects
- Glutamic Acid/pharmacology
- Melatonin/pharmacology
- Oxidative Stress/drug effects
- Proto-Oncogene Proteins c-bcl-2/genetics
- Proto-Oncogene Proteins c-bcl-2/metabolism
- Receptor, Melatonin, MT1/genetics
- Receptor, Melatonin, MT1/metabolism
- Receptor, Melatonin, MT2/genetics
- Receptor, Melatonin, MT2/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- bcl-2-Associated X Protein/genetics
- bcl-2-Associated X Protein/metabolism
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Affiliation(s)
- Arabinda Das
- Division of Neurology, Department of Neurosciences, Medical University of South Carolina, Charleston, SC
| | - Amogh Belagodu
- Division of Neurology, Department of Neurosciences, Medical University of South Carolina, Charleston, SC
| | - Russel J. Reiter
- Department of Cellular and Structural Biology, University of Texas, San Antonio, TX
| | - Swapan K. Ray
- Department of Pathology, Microbiology and Immunology, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Naren L. Banik
- Division of Neurology, Department of Neurosciences, Medical University of South Carolina, Charleston, SC
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65
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Esposito E, Genovese T, Caminiti R, Bramanti P, Meli R, Cuzzocrea S. Melatonin regulates matrix metalloproteinases after traumatic experimental spinal cord injury. J Pineal Res 2008; 45:149-56. [PMID: 18298463 DOI: 10.1111/j.1600-079x.2008.00569.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The matrix metalloproteinases (MMPs) are important enzymes that regulate developmental processes, maintain normal physiology in adulthood and have reparative roles at specific stages after an insult to the nervous system. MMPs, particularly MMP-9/gelatinase B, promote early inflammation and barrier disruption after spinal cord injury (SCI). Recently, we have reported that the pineal secretory product melatonin exerts important anti-inflammatory effects in an experimental model of SCI induced by the application of vascular clips (force of 24 g) to the dura after a four-level T5-T8 laminectomy. However, no reports are available on the relationship between the activity of MMPs and melatonin's anti-inflammatory effects. The aim of the present study was to evaluate whether the protective effect of melatonin observed in SCI is related to the regulation of MMP-9 and MMP-2 in mice. Biochemical and zymographic methods were used to analyze MMP-9 and -2 expression and activities in spinal cord tissue from SCI-treated mice at 24 hr after the trauma. Our studies reveal that melatonin reduced SCI and lipid peroxidation in spinal cord at 24 hr after SCI. Melatonin also diminished proMMP-9 and -2 activities that were induced in the spinal cord tissues at 24 hr after SCI. The reduced activities of MMP-9 and -2 were associated with depressed expression of TNF-alpha. We propose that melatonin's ability to reduce SCI in mice is also related to a reduction in MMP-9 and MMP-2 activity and expression.
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Affiliation(s)
- Emanuela Esposito
- Department of Experimental Pharmacology, University of Naples Federico II, Napoli, Italy
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66
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Zhou J, Zhang S, Zhao X, Wei T. Melatonin impairs NADPH oxidase assembly and decreases superoxide anion production in microglia exposed to amyloid-beta1-42. J Pineal Res 2008; 45:157-65. [PMID: 18298462 DOI: 10.1111/j.1600-079x.2008.00570.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Melatonin shows significant protective effects in Alzheimer's disease (AD) models in vitro and in vivo; these effects are related to its function as an antioxidant. The source of reactive oxygen species (ROS) generation in the AD brain is primarily the amyloid-beta (Abeta)- activated microglial nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. However, the effects of melatonin on the activation of NADPH oxidase remain unclear. In the present study, the cultures of microglia were incubated in the presence of fibrillar Abeta(1-42), which induces the assembly and the activation of NADPH oxidase, and triggers the production of superoxide anion-derived ROS. Pretreatment of microglia with melatonin dose-dependently prevents the activation of NADPH oxidase and decreases the production of ROS. Melatonin inhibits the phosphorylation of the p47(phox) subunit of NADPH oxidase via a PI3K/Akt-dependent signalling pathway, blocks the translocation of p47(phox) and p67(phox) subunit to the membrane, down-regulates the binding of p47(phox) to gp91(phox), and impairs the assembly of NADPH oxidase. Our data offer new insights into the mechanism of inhibiting ROS generation by melatonin in Abeta-activated microglia. Inhibition of ROS production indirectly might be the underlying mechanism for the neuroprotection by melatonin in the AD brain.
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Affiliation(s)
- Juefei Zhou
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Science, Graduate University of Chinese Academy of Science, Beijing, China
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67
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Siwicka A, Moleda Z, Wojtasiewicz K, Zawadzka A, Maurin JK, Panasiewicz M, Pacuszka T, Czarnocki Z. The oxidation products of melatonin derivatives exhibit acetylcholinesterase and butyrylcholinesterase inhibitory activity. J Pineal Res 2008; 45:40-9. [PMID: 18284552 DOI: 10.1111/j.1600-079x.2008.00554.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
It is already well documented that melatonin exhibits strong antioxidant properties. It traps several reactive oxygen species including singlet oxygen, peroxyl and hydroxyl radicals. Also, peroxynitrite-induced reactions are inhibited by melatonin. The oxidation of melatonin by singlet molecular oxygen [O(2) ((1)Delta(g))] may produce cyclic 3-hydroxymelatonin whose structure we have already studied. In this investigation we report on the synthesis of several melatonin analogues having a carbamate substituent instead of the methoxy group at 5 position of the indole ring. These compounds behave analogously to melatonin with respect to singlet oxygen and produce the corresponding cyclic 3-hydroxymelatonin analogues. The structures of the products were investigated with spectral methods and X-ray crystallography. The compounds obtained possess the 2,3,8,8a-tetrahydropyrrolo[2,3-b]indole heterocyclic system which is a structural motif characteristic of alkaloids, physostigmine and phenserine, that are potent acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitors used in the Alzheimer's disease treatment. We measured the inhibitory activity of the obtained compounds against AChE and BChE from human erythrocytes and serum. In the case of the compounds having a phenylcarbamate and methoxyphenylcarbamate substituents, the inhibitory activity (IC(50)) ranged from 0.252 +/- 0.033 to 3.804 +/- 0.581 microM. Other compounds were less active and showed rather complex interactions with the structure-activity relationship in need of further investigation.
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68
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Huang SH, Cao XJ, Wei W. Melatonin decreases TLR3-mediated inflammatory factor expression via inhibition of NF-kappa B activation in respiratory syncytial virus-infected RAW264.7 macrophages. J Pineal Res 2008; 45:93-100. [PMID: 18312297 DOI: 10.1111/j.1600-079x.2008.00560.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Double-stranded (ds) RNA has been identified as a ligand for Toll-like receptor 3 (TLR3). Respiratory syncytial virus (RSV), a single-stranded RNA virus and a major respiratory pathogen and pneumovirus in human infants pathogenesis of which relies on early inflammatory and immune events of the host in response to RSV, could be recognized by TLR3 sensing viral dsRNA produced during replication. The downstream signaling pathway from TLR3 leads to activation of IFN regulatory factor (IRF)-3 and/or NF-kappaB and subsequent expression of numerous proinflammatory factors. Melatonin (MT) is an effective regulator of the immune system. To determine the molecular mechanisms responsible for the suppressive effect of MT on RSV infection, we analyzed signaling molecules involved in the TLR3-mediated activation of inflammatory factors in macrophages infected with RSV and the modulatory role of MT on these mediators. We report that RSV infection of RAW264.7 macrophages time-dependently stimulate the rapid activation of TLR3 and NF-kappaB, as well as subsequent NF-kappaB-dependent gene expression such as those encoding TNF-alpha and inducible nitric oxide synthase. Moreover, we demonstrate that MT decreased TLR3-mediated downstream gene expression in RSV-infected macrophages in a dose- and time-dependent manner, and that MT inhibition of NF-kappaB activity seemed to be the key event required to explain the reduction in inflammatory gene expression caused by MT. But MT did not influence TLR3 at either the protein or mRNA level or MyD88 transcription. These results could be related to the beneficial immunoregulatory role of MT in RSV-infected macrophages and address the possible therapeutic potential of this indoleamine in human RSV diseases.
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Affiliation(s)
- Sheng-Hai Huang
- Institute of Clinical Pharmacology, Key Laboratory of Anti-inflammatory and Immunopharmacology in Anhui Province, Anhui Medical University, Hefei, China
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69
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Oba S, Nakamura K, Sahashi Y, Hattori A, Nagata C. Consumption of vegetables alters morning urinary 6-sulfatoxymelatonin concentration. J Pineal Res 2008; 45:17-23. [PMID: 18205730 DOI: 10.1111/j.1600-079x.2007.00549.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Melatonin, which is contained in certain vegetables, may have an influence on circulatory melatonin concentrations. This study examined the effects of the consumption of vegetables on 6-sulfatoxymelatonin concentrations in morning urine. Ninety-four healthy women aged 24-55 were recruited through a city public health center in Japan. The women randomly allocated to the intervention group were requested to consume high amounts of six selected vegetables, with a target of 350 g/day for 65 days, while those in the control group were asked to avoid the same six vegetables during the same period. First-void morning urine was collected before and at the end of the intervention period, and creatinine-adjusted 6-sulfatoxymelatonin concentrations were measured. At the end of the intervention period, daily mean intake of melatonin from the six vegetables was 1288.0 ng in the intervention group and 5.3 ng in the control group. In the intervention group, the mean concentration of 6-sulfatoxymelatonin changed from 48.1 [95% confidence interval (CI): 40.4-57.2] ng/mg creatinine to 49.6 (95% CI: 42.8-57.3) ng/mg creatinine across the intervention period. In the control group, the mean concentration of 6-sulfatoxymelatonin changed from 55.5 (95% CI: 48.7-63.2) ng/mg creatinine to 50.8 (95% CI: 44.0-58.7) ng/mg creatinine across the intervention period. A comparison of the two groups with regard to the changes in the 6-sulfatoxymelatonin concentrations across the intervention period showed a significant difference (P = 0.03). The results indicate that increased consumption of vegetables raises circulatory melatonin concentrations.
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Affiliation(s)
- Shino Oba
- Department of Prevention for Lifestyle-related Diseases, Gifu University Graduate School of Medicine, Gifu, Japan
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70
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Wu JY, Tsou MY, Chen TH, Chen SJ, Tsao CM, Wu CC. Therapeutic effects of melatonin on peritonitis-induced septic shock with multiple organ dysfunction syndrome in rats. J Pineal Res 2008; 45:106-16. [PMID: 18298464 DOI: 10.1111/j.1600-079x.2008.00567.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The pathogenesis of multiple organ dysfunction syndrome (MODS) in septic shock is complicated and not fully understood. Some studies show that an overproduction of nitric oxide (NO) leads to the refractory hypotension and multiple organ failure, while other studies suggest that free radicals, e.g. superoxide (O(2)(-)), contribute to the detrimental effect on vascular responsiveness and tissue/organ damage. Thus, this study was performed on the Wistar rat by using cecal ligation and puncture (CLP) to induce septic shock-associated MODS. We evaluated the effect of an antioxidant melatonin in CLP-induced septic rats and demonstrated that melatonin (3 mg/kg, i.v. at 3, 6, 12 hr after CLP) significantly (a) attenuated hyporeactivity to norepinephrine and delayed hypotension, (b) reduced plasma index of hepatic and renal dysfunction, (c) diminished plasma NO and interleukin-1beta (IL-1beta) concentrations as well as aortic O(2)(-) levels, (d) reduced marked infiltration of polymorphonuclear neutrophils (PMNs) in the lung and liver tissues, and (e) promoted the survival rate at 18 hr to twofold compared with the CLP alone group. The current study underlined the inhibition of plasma NO and IL-1beta as well as aortic O(2)(-) production and the reduction of PMN infiltration may lead to the amelioration of MODS, which may contribute to the beneficial effect of antioxidants (e.g. melatonin in this study) in conscious rats with peritonitis-induced lethality. Thus, the antioxidant could be a novel agent for the treatment of septic animals or patients in the early stage.
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Affiliation(s)
- Jeng-Yuan Wu
- Division of Thoracic Surgery, Taichung Tzu Chi General Hospital, Taichung, Taiwan
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71
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Seever K, Hardeland R. Novel pathway for N1-acetyl-5-methoxykynuramine: UVB-induced liberation of carbon monoxide from precursor N1-acetyl-N2-formyl-5-methoxykynuramine. J Pineal Res 2008; 44:450-5. [PMID: 18194200 DOI: 10.1111/j.1600-079x.2007.00550.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Irradiation of the melatonin metabolite N(1)-acetyl-N(2)-formyl-5-methoxykynuramine (AFMK) with UV light of 254 nm causes the release of carbon monoxide (CO) and, thus, deformylation to N(1)-acetyl-5-methoxykynuramine (AMK). Liberation of CO was demonstrated by reduction of PdCl(2) to metallic palladium, under avoidance of actions by other reductants. Photochemical AMK formation was not due to UV-induced hydroxyl radicals, because the reaction also took place with high efficiency in ethanol and 2-propanol. Moreover, AMK was generated from AFMK by UVB on a dry thin layer chromatographic plate. Although AMK seems to be the major primary product generated by UVB radiation, prolonged exposure of AFMK led to various other products, especially formed by destruction of AMK, as shown by irradiation of this latter compound. With regard to the demonstration of melatonin in skin and substantial amounts of AFMK in keratinocytes, these findings may be of dermatologic relevance.
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Affiliation(s)
- Katinka Seever
- Johann Friedrich Blumenbach Institute of Zoology and Anthropology, University of Göttingen, Göttingen, Germany
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72
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Krotzky M, Hardeland R. Metabolism of the Melatonin Metabolite N1-Acetyl-N2-formyl-5-methoxykynuramine in Saccharomyces cerevisiae. CYTOLOGIA 2008. [DOI: 10.1508/cytologia.73.123] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Mirko Krotzky
- Johann Friedrich Blumenbach Institute of Zoology and Anthropology, University of Goettingen
| | - Rüdiger Hardeland
- Johann Friedrich Blumenbach Institute of Zoology and Anthropology, University of Goettingen
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