OBJECTIVES: Melatonin, a hormonal product of the pineal gland, is now known to be a multi-faceted free radical scavenger and anti-oxidant. Since little information is available regarding the action of melatonin on the heart, we studied the effects of melatonin on adult ventricular myocytes subjected to chemical hypoxia and reoxygenation. METHODS: Adult rat ventricular myocytes were preloaded with tetramethylrhodamine (TMRM) in combination with one of the following fluorophores: dichlorodihydrofluorescein diacetate (DCDHF), dihydrorhodamine 123 (DHR) or fluo 3 (Fluo) and then investigated with confocal laser scanning microscopy. Chemical hypoxia was induced by addition of 1.5 mM KCN and 20 mM deoxyglucose to the superfusion buffer. Melatonin (50-100 microM) was added at intervals during the protocol. RESULTS: Cells subjected to 12.5 min chemical hypoxia showed marked morphological changes, increased fluorescence intensity of DCDHF, DHR and Fluo, suggesting Ca2+ accumulation and generation of H2O2 and reactive oxygen species. The number of cells showing increased fluorescence also increased significantly. Melatonin (50 and 100 microM) caused a significant reduction in morphological changes, number of cells with increased fluorescence and fluorescence intensity of DHR and Fluo, (but not DCDHF). CONCLUSION: Melatonin effectively reduced damage induced by chemical hypoxia in adult cardiomyocytes, probably by virtue of its effects on reactive oxygen species generation and intracellular Ca2+ accumulation. Copyright 2001 Academic Press.
OBJECTIVES:Melatonin, a hormonal product of the pineal gland, is now known to be a multi-faceted free radical scavenger and anti-oxidant. Since little information is available regarding the action of melatonin on the heart, we studied the effects of melatonin on adult ventricular myocytes subjected to chemical hypoxia and reoxygenation. METHODS: Adult rat ventricular myocytes were preloaded with tetramethylrhodamine (TMRM) in combination with one of the following fluorophores: dichlorodihydrofluorescein diacetate (DCDHF), dihydrorhodamine 123 (DHR) or fluo 3 (Fluo) and then investigated with confocal laser scanning microscopy. Chemical hypoxia was induced by addition of 1.5 mM KCN and 20 mM deoxyglucose to the superfusion buffer. Melatonin (50-100 microM) was added at intervals during the protocol. RESULTS: Cells subjected to 12.5 min chemical hypoxia showed marked morphological changes, increased fluorescence intensity of DCDHF, DHR and Fluo, suggesting Ca2+ accumulation and generation of H2O2 and reactive oxygen species. The number of cells showing increased fluorescence also increased significantly. Melatonin (50 and 100 microM) caused a significant reduction in morphological changes, number of cells with increased fluorescence and fluorescence intensity of DHR and Fluo, (but not DCDHF). CONCLUSION:Melatonin effectively reduced damage induced by chemical hypoxia in adult cardiomyocytes, probably by virtue of its effects on reactive oxygen species generation and intracellular Ca2+ accumulation. Copyright 2001 Academic Press.
Authors: Dun-Xian Tan; Lucien C Manchester; Rosa M Sainz; Juan C Mayo; Josefa León; Russel J Reiter Journal: Endocrine Date: 2005-07 Impact factor: 3.633
Authors: Zhongyi Chen; Chu C Chua; Jinping Gao; Kao-Wei Chua; Ye-Shih Ho; Ronald C Hamdy; Balvin H L Chua Journal: J Pineal Res Date: 2008-12-11 Impact factor: 13.007
Authors: Venkatramanujam Srinivasan; D Warren Spence; Seithikurippu R Pandi-Perumal; Gregory M Brown; Daniel P Cardinali Journal: Int J Alzheimers Dis Date: 2011-05-04
Authors: Ksenia A Sedova; Olesya G Bernikova; Julia I Cuprova; Alexandra D Ivanova; Galina A Kutaeva; Michael G Pliss; Ekaterina V Lopatina; Marina A Vaykshnorayte; Emiliano R Diez; Jan E Azarov Journal: Int J Mol Sci Date: 2019-12-15 Impact factor: 5.923
Authors: Alena S Tsvetkova; Olesya G Bernikova; Natalya J Mikhaleva; Darya S Khramova; Alexey O Ovechkin; Marina M Demidova; Pyotr G Platonov; Jan E Azarov Journal: Int J Mol Sci Date: 2020-12-30 Impact factor: 5.923