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Ben-Azu B, Toloyai PEY, Adebesin A, Ojiokor VO, Adebayo OG, Fokoua AR, Moke GE, Ejukolemu EJ, Akpojevughe IOO, Abdulkadir AM, Okwuchi E. Alcohol-exacerbates post-traumatic stress psychiatric behavior and its neuropathological sequalae in experimental mice: preventive effects of morin. Alcohol 2024:S0741-8329(24)00111-3. [PMID: 39094850 DOI: 10.1016/j.alcohol.2024.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 06/28/2024] [Accepted: 07/29/2024] [Indexed: 08/04/2024]
Abstract
Posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) are very prevalent and co-occurring. It is unclear how alcohol exacerbates PTSD predicaments owing to less characterized pathophysiological mechanisms. Also, studies on pharmacological agents that can effectively reverse PTSD-AUD comorbidity have, to date, been scarce. Hence, we designed a methodological approach to investigate the pathophysiological mechanisms and pharmacological outcomes of morin, a neuroprotective flavonoid in mice. After 7 days of PTSD following single-prolonged stress (SPS) induction in mice, the PTSD mice were exposed to intermittent binge ethanol administration using ethanol (2g/kg, oral gavage) every other day, alongside daily morin (50 and 100mg/kg) or fluoxetine (10mg/kg) from days 8-21. The consequences of PTSD-AUD behavior, hypothalamic-pituitary-adrenal-axis (HPA-axis) dysfunction, neurochemistry, oxidative/nitrergic stress, and inflammation were evaluated in the prefrontal-cortex (PFC), striatum, and hippocampus of mice. The exacerbated anxiety-like behavior, and spatial/non-spatial memory deficits, with general depressive phenotypes and social stress susceptibility by SPS-ethanol interaction, were alleviated by morin and fluoxetine, evidenced by reduced corticosterone release and adrenal hypertrophy. SPS-ethanol exacerbates dopamine, serotonin, and glutamic acid decarboxylase alterations, and monoamine oxidase-B and acetylcholinesterase hyperactivities in the striatum, PFC, and hippocampus, respectively, which were prevented by morin. Compared to SPS-ethanol aggravation, morin prevented TNF-α, and IL-6 release, malondialdehyde and nitrite levels, with improved antioxidant (glutathione, superoxide-dismutase, catalase) levels in the hippocampus, PFC, and striatum. Overall, these findings suggest that AUD exacerbated PTSD might be primarily connected, among other mechanisms, with aggravated HPA-axis dysfunction, upregulated neurochemical degradative enzymes, enhancement of oxidative/nitrergic stress and neuroinflammation, stereo-selectively in the mice brains, which morin abated via the preventive mechanisms.
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Affiliation(s)
- Benneth Ben-Azu
- DELSU Joint Canada-Israel Neuroscience and Biopsychiatry Laboratory, Department of Pharmacology, Faculty of Basic Medical Sciences, Delta State University, Abraka, Nigeria.
| | - Pere-Ebi Y Toloyai
- Department of Medical Biochemistry, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
| | - Adaeze Adebesin
- Department of Pharmacology and Therapeutics, Faculty of Basic Medical Sciences, Abafemi Awolowo College of Health Sciences, Olabisi Onabanjo University, Sagamu Campus, Sagamu, Ogun State, Nigeria
| | - Vivian O Ojiokor
- Department of Anatomy, Faculty of Basic Medical Sciences, College of Medicine, Enugu State University of Science and Technology (ESUT), Enugu, Enugu State, Nigeria
| | - Olusegun G Adebayo
- DELSU Joint Canada-Israel Neuroscience and Biopsychiatry Laboratory, Department of Pharmacology, Faculty of Basic Medical Sciences, Delta State University, Abraka, Nigeria; Neurophysiology Unit, Department of Physiology, Faculty of Basic Medical Sciences, University of Ibadan, Ibadan, Oyo State, Nigeria
| | - Aliance Romain Fokoua
- DELSU Joint Canada-Israel Neuroscience and Biopsychiatry Laboratory, Department of Pharmacology, Faculty of Basic Medical Sciences, Delta State University, Abraka, Nigeria; Research unit of Neuroinflammatory and Cardiovascular Pharmacology, Department of Animal Biology, Faculty of Sciences, University of Dschang, Cameroon
| | - Goodes E Moke
- DELSU Joint Canada-Israel Neuroscience and Biopsychiatry Laboratory, Department of Pharmacology, Faculty of Basic Medical Sciences, Delta State University, Abraka, Nigeria
| | - Elo J Ejukolemu
- DELSU Joint Canada-Israel Neuroscience and Biopsychiatry Laboratory, Department of Pharmacology, Faculty of Basic Medical Sciences, Delta State University, Abraka, Nigeria
| | - Ife-Oluwa O Akpojevughe
- Department of Medical Biochemistry, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
| | - Abdulkareem M Abdulkadir
- Department of Medical Biochemistry, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
| | - Ephraim Okwuchi
- Department of Medical Biochemistry, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
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Wang M, Wen W, Chen Y, Yishajiang S, Li Y, Li Z, Zhang X. TRPC5 channel participates in myocardial injury in chronic intermittent hypoxia. Clinics (Sao Paulo) 2024; 79:100368. [PMID: 38703717 PMCID: PMC11087918 DOI: 10.1016/j.clinsp.2024.100368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 03/25/2024] [Accepted: 04/14/2024] [Indexed: 05/06/2024] Open
Abstract
OBJECTIVE The purpose of this study is to develop an animal model of Chronic Intermittent Hypoxia (CIH) and investigate the role of the TRPC5 channel in cardiac damage in OSAHS rats. METHODS Twelve male Sprague Dawley rats were randomly divided into the CIH group and the Normoxic Control (NC) group. Changes in structure, function, and pathology of heart tissue were observed through echocardiography, transmission electron microscopy, HE-staining, and TUNEL staining. RESULTS The Interventricular Septum thickness at diastole (IVSd) and End-Diastolic Volume (EDV) of rats in the CIH group significantly increased, whereas the LV ejection fraction and LV fraction shortening significantly decreased. TEM showed that the myofilaments in the CIH group were loosely arranged, the sarcomere length varied, the cell matrix dissolved, the mitochondrial cristae were partly flocculent, the mitochondrial outer membrane dissolved and disappeared, and some mitochondria were swollen and vacuolated. The histopathological examination showed that the cardiomyocytes in the CIH group were swollen with granular degeneration, some of the myocardial fibers were broken and disorganized, and most of the nuclei were vacuolar and hypochromic. CONCLUSION CIH promoted oxidative stress, the influx of Ca2+, and the activation of the CaN/NFATc signaling pathway, which led to pathological changes in the morphology and ultrastructure of cardiomyocytes, the increase of myocardial apoptosis, and the decrease of myocardial contractility. These changes may be associated with the upregulation of TRPC5.
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Affiliation(s)
- Mengmeng Wang
- Department of Hypertension, The First Affiliated Hospital of Xinjiang Medical University, China
| | - Wen Wen
- Department of Hypertension, The First Affiliated Hospital of Xinjiang Medical University, China
| | - Yulan Chen
- Department of Hypertension, The First Affiliated Hospital of Xinjiang Medical University, China.
| | - Sharezati Yishajiang
- Department of Hypertension, The First Affiliated Hospital of Xinjiang Medical University, China
| | - Yu Li
- Second Department of General Internal Medicine, The First Affiliated Hospital of Xinjiang Medical University, China
| | - Zhiqiang Li
- Laboratory Animal Center, Xinjiang Medical University, China
| | - Xiangyang Zhang
- Department of Hypertension, The First Affiliated Hospital of Xinjiang Medical University, China
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Srivastava P, Sudevan ST, Thennavan A, Mathew B, Kanthlal SK. Inhibiting Monoamine Oxidase in CNS and CVS would be a Promising Approach to Mitigating Cardiovascular Complications in Neurodegenerative Disorders. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2024; 23:331-341. [PMID: 36872357 DOI: 10.2174/1871527322666230303115236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 12/17/2022] [Accepted: 01/03/2023] [Indexed: 03/07/2023]
Abstract
The flavoenzyme monoamine oxidases (MAOs) are present in the mitochondrial outer membrane and are responsible for the metabolism of biogenic amines. MAO deamination of biological amines produces toxic byproducts such as amines, aldehydes, and hydrogen peroxide, which are significant in the pathophysiology of multiple neurodegenerative illnesses. In the cardiovascular system (CVS), these by-products target the mitochondria of cardiac cells leading to their dysfunction and producing redox imbalance in the endothelium of the blood vessels. This brings up the biological relationship between the susceptibility of getting cardiovascular disorders in neural patients. In the current scenario, MAO inhibitors are highly recommended by physicians worldwide for the therapy and management of various neurodegenerative disorders. Many interventional studies reveal the benefit of MAO inhibitors in CVS. Drug candidates who can target both the central and peripheral MAO could be a better to compensate for the cardiovascular comorbidities observed in neurodegenerative patients.
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Affiliation(s)
- Princika Srivastava
- Department of Pharmacology, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, AIMS Health Science Campus, Kochi, 682 041, Kerala, India
| | - Sachithra Thazhathuveedu Sudevan
- Department of Pharmaceutical Chemistry, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, AIMS Health Sciences Campus, Kochi, 682 041, India
| | - Arumugam Thennavan
- Central Lab Animal Facility, Amrita Vishwa Vidyapeetham, AIMS Health Science Campus, Kochi, 682 041, Kerala, India
| | - Bijo Mathew
- Department of Pharmaceutical Chemistry, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, AIMS Health Sciences Campus, Kochi, 682 041, India
| | - S K Kanthlal
- Department of Pharmacology, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, AIMS Health Science Campus, Kochi, 682 041, Kerala, India
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Schulz R, Schlüter KD. Importance of Mitochondria in Cardiac Pathologies: Focus on Uncoupling Proteins and Monoamine Oxidases. Int J Mol Sci 2023; 24:ijms24076459. [PMID: 37047436 PMCID: PMC10095304 DOI: 10.3390/ijms24076459] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Revised: 03/22/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023] Open
Abstract
On the one hand, reactive oxygen species (ROS) are involved in the onset and progression of a wide array of diseases. On the other hand, these are a part of signaling pathways related to cell metabolism, growth and survival. While ROS are produced at various cellular sites, in cardiomyocytes the largest amount of ROS is generated by mitochondria. Apart from the electron transport chain and various other proteins, uncoupling protein (UCP) and monoamine oxidases (MAO) have been proposed to modify mitochondrial ROS formation. Here, we review the recent information on UCP and MAO in cardiac injuries induced by ischemia-reperfusion (I/R) as well as protection from I/R and heart failure secondary to I/R injury or pressure overload. The current data in the literature suggest that I/R will preferentially upregulate UCP2 in cardiac tissue but not UCP3. Studies addressing the consequences of such induction are currently inconclusive because the precise function of UCP2 in cardiac tissue is not well understood, and tissue- and species-specific aspects complicate the situation. In general, UCP2 may reduce oxidative stress by mild uncoupling and both UCP2 and UCP3 affect substrate utilization in cardiac tissue, thereby modifying post-ischemic remodeling. MAOs are important for the physiological regulation of substrate concentrations. Upon increased expression and or activity of MAOs, however, the increased production of ROS and reactive aldehydes contribute to cardiac alterations such as hypertrophy, inflammation, irreversible cardiomyocyte injury, and failure.
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Sharma S, Sharma P, Subedi U, Bhattarai S, Miller C, Manikandan S, Batinic-Haberle I, Spasojevic I, Sun H, Panchatcharam M, Miriyala S. Mn(III) Porphyrin, MnTnBuOE-2-PyP 5+, Commonly Known as a Mimic of Superoxide Dismutase Enzyme, Protects Cardiomyocytes from Hypoxia/Reoxygenation Induced Injury via Reducing Oxidative Stress. Int J Mol Sci 2023; 24:6159. [PMID: 37047131 PMCID: PMC10094288 DOI: 10.3390/ijms24076159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/15/2023] [Accepted: 03/22/2023] [Indexed: 04/14/2023] Open
Abstract
Myocardial ischemia-reperfusion injury (I/R) causes damage to cardiomyocytes through oxidative stress and apoptosis. We investigated the cardioprotective effects of MnTnBuOE-2-PyP5+ (BMX-001), a superoxide dismutase mimic, in an in vitro model of I/R injury in H9c2 cardiomyocytes. We found that BMX-001 protected against hypoxia/reoxygenation (H/R)-induced oxidative stress, as evident by a significant reduction in intracellular and mitochondrial superoxide levels. BMX-001 pre-treatment also reduced H/R-induced cardiomyocyte apoptosis, as marked by a reduction in TUNEL-positive cells. We further demonstrated that BMX-001 pre-treatment significantly improved mitochondrial function, particularly O2 consumption, in mouse adult cardiomyocytes subjected to H/R. BMX-001 treatment also attenuated cardiolipin peroxidation, 4-hydroxynonenal (4-HNE) level, and 4-HNE adducted proteins following H/R injury. Finally, the pre-treatment with BMX-001 improved cell viability and lactate dehydrogenase (LDH) activity in H9c2 cells following H/R injury. Our findings suggest that BMX-001 has therapeutic potential as a cardioprotective agent against oxidative stress-induced H/R damage in H9c2 cardiomyocytes.
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Affiliation(s)
- Sudha Sharma
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences-Shreveport, Shreveport, LA 71103, USA
| | - Papori Sharma
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences-Shreveport, Shreveport, LA 71103, USA
| | - Utsab Subedi
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences-Shreveport, Shreveport, LA 71103, USA
| | - Susmita Bhattarai
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences-Shreveport, Shreveport, LA 71103, USA
| | - Chloe Miller
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences-Shreveport, Shreveport, LA 71103, USA
| | - Shrivats Manikandan
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences-Shreveport, Shreveport, LA 71103, USA
| | - Ines Batinic-Haberle
- Department of Radiation Oncology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Ivan Spasojevic
- Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
- Pharmacokinetics/Pharmacodynamics (PK/PD) Core Laboratory, Duke Cancer Institute, Duke University School of Medicine, Durham, NC 27710, USA
| | - Hong Sun
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences-Shreveport, Shreveport, LA 71103, USA
| | - Manikandan Panchatcharam
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences-Shreveport, Shreveport, LA 71103, USA
| | - Sumitra Miriyala
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences-Shreveport, Shreveport, LA 71103, USA
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Merce AP, Ionică LN, Bînă AM, Popescu S, Lighezan R, Petrescu L, Borza C, Sturza A, Muntean DM, Creţu OM. Monoamine oxidase is a source of cardiac oxidative stress in obese rats: the beneficial role of metformin. Mol Cell Biochem 2023; 478:59-67. [PMID: 35723772 DOI: 10.1007/s11010-022-04490-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 05/31/2022] [Indexed: 01/17/2023]
Abstract
Diet-induced metabolic diseases, such as obesity, metabolic syndrome, and type 2 diabetes (T2DM) are the global threatening epidemics that share cardiovascular oxidative stress as common denominator. Monoamine oxidase (MAO) has recently emerged as a constant source of reactive oxygen species (ROS) in DM. Metformin, the first-line drug in T2DM, elicits cardiovascular protection via pleiotropic effects. The present study was aimed to assess the contribution of MAO to the early cardiac oxidative stress in a rat model of high-calorie junk food (HCJF) diet-induced obesity and prediabetes and whether metformin can alleviate it. After 6 months of HCJF, rats developed obesity and hyperglycemia. Hearts were isolated and used for the evaluation of MAO expression and ROS production. Experiments were performed in the presence vs absence of metformin (10 µM) and MAO-A and B inhibitors (clorgyline and selegiline, 10 µM), respectively. Both MAO isoforms were overexpressed and led to increased ROS generation in cardiac samples harvested from the obese animals. Acute treatment with metformin and MAO inhibitors was able to mitigate oxidative stress. More important, metformin downregulated MAO expression in the diseased samples. In conclusion, MAO contributes to oxidative stress in experimental obesity and can be targeted with metformin.
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Affiliation(s)
- Adrian P Merce
- Department of Functional Sciences - Pathophysiology, "Victor Babeş" University of Medicine and Pharmacy, Eftimie Murgu Sq. No. 2, 300041, Timişoara, Romania.,Center for Translational Research and Systems Medicine, "Victor Babeş" University of Medicine and Pharmacy, EftimieMurgu Sq. No. 2, 300041, Timişoara, Romania
| | - Loredana N Ionică
- Department of Functional Sciences - Pathophysiology, "Victor Babeş" University of Medicine and Pharmacy, Eftimie Murgu Sq. No. 2, 300041, Timişoara, Romania.,Center for Translational Research and Systems Medicine, "Victor Babeş" University of Medicine and Pharmacy, EftimieMurgu Sq. No. 2, 300041, Timişoara, Romania
| | - Anca M Bînă
- Department of Functional Sciences - Pathophysiology, "Victor Babeş" University of Medicine and Pharmacy, Eftimie Murgu Sq. No. 2, 300041, Timişoara, Romania.,Center for Translational Research and Systems Medicine, "Victor Babeş" University of Medicine and Pharmacy, EftimieMurgu Sq. No. 2, 300041, Timişoara, Romania
| | - Simona Popescu
- Department of Internal Medicine VII - Diabetes, Nutrition, Metabolic Diseases, "Victor Babeş" University of Medicine and Pharmacy, Eftimie Murgu Sq. No. 2, 300041, Timişoara, Romania
| | - Rodica Lighezan
- Department of Infectious Diseases-Parasitology, "Victor Babeş" University of Medicine and Pharmacy, Eftimie Murgu Sq. No. 2, 300041, Timişoara, Romania
| | - Lucian Petrescu
- Department of Cardiology - Cardiology II, "Victor Babeş" University of Medicine and Pharmacy, Eftimie Murgu Sq. No. 2, 300041, Timişoara, Romania
| | - Claudia Borza
- Department of Functional Sciences - Pathophysiology, "Victor Babeş" University of Medicine and Pharmacy, Eftimie Murgu Sq. No. 2, 300041, Timişoara, Romania.,Center for Translational Research and Systems Medicine, "Victor Babeş" University of Medicine and Pharmacy, EftimieMurgu Sq. No. 2, 300041, Timişoara, Romania
| | - Adrian Sturza
- Department of Functional Sciences - Pathophysiology, "Victor Babeş" University of Medicine and Pharmacy, Eftimie Murgu Sq. No. 2, 300041, Timişoara, Romania. .,Center for Translational Research and Systems Medicine, "Victor Babeş" University of Medicine and Pharmacy, EftimieMurgu Sq. No. 2, 300041, Timişoara, Romania. .,Department of Functional Sciences III - Pathophysiology, Center for Translational Research and Systems Medicine, "Victor Babeş" University of Medicine and Pharmacy of Timişoara , Eftimie Murgu Sq. No. 2, 300041, Timişoara, Romania.
| | - Danina M Muntean
- Department of Functional Sciences - Pathophysiology, "Victor Babeş" University of Medicine and Pharmacy, Eftimie Murgu Sq. No. 2, 300041, Timişoara, Romania. .,Center for Translational Research and Systems Medicine, "Victor Babeş" University of Medicine and Pharmacy, EftimieMurgu Sq. No. 2, 300041, Timişoara, Romania. .,Department of Functional Sciences III - Pathophysiology, Center for Translational Research and Systems Medicine, "Victor Babeş" University of Medicine and Pharmacy of Timişoara , Eftimie Murgu Sq. No. 2, 300041, Timişoara, Romania.
| | - Octavian M Creţu
- Department of Surgery - Surgical Semiotics, "Victor Babeş" University of Medicine and Pharmacy, Eftimie Murgu Sq. No. 2, 300041, Timişoara, Romania.,Center for Hepato‑Biliary and Pancreatic Surgery, "Victor Babeş" University of Medicine and Pharmacy Timişoara, Eftimie Murgu Sq. No. 2, 300041, Timişoara, Romania
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Sonobe T, Akiyama T, Pearson JT. Transporter-dependent uptake and metabolism of myocardial interstitial serotonin in the rat heart. J Physiol Sci 2022; 72:27. [DOI: 10.1186/s12576-022-00852-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 10/13/2022] [Indexed: 11/10/2022]
Abstract
AbstractTo investigate the roles of the serotonin (5-HT) transporter (SERT) and plasma membrane monoamine transporter (PMAT) in 5-HT uptake and its metabolism in the heart, we monitored myocardial interstitial levels of 5-HT and 5-HIAA, a metabolite of 5-HT by monoamine oxidase (MAO), in anesthetized rats using a microdialysis technique. Fluoxetine (SERT inhibitor), decynium-22 (PMAT inhibitor), or their mixture was locally administered by reverse-microdialysis for 60 min. Subsequently, pargyline (MAO inhibitor) was co-administered. Fluoxetine rapidly increased dialysate 5-HT concentration, while decynium-22 gradually increased it. The mixture induced a larger increase in dialysate 5-HT concentration compared to fluoxetine or decynium-22 alone. Fluoxetine increased dialysate 5-HIAA concentration, and this increase was abolished by pargyline. Decynium-22 and the mixture did not change dialysate 5-HIAA concentration, which were not affected by pargyline. Both SERT and PMAT regulate myocardial interstitial 5-HT levels by its uptake; however, 5-HT uptake via PMAT leads to 5-HT metabolism by MAO.
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8
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Sonobe T, Akiyama T, Pearson JT. Carrier-mediated serotonin efflux induced by pharmacological anoxia in the rat heart in vivo. Clin Exp Pharmacol Physiol 2021; 48:1685-1692. [PMID: 34411314 DOI: 10.1111/1440-1681.13576] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 08/04/2021] [Accepted: 08/16/2021] [Indexed: 11/30/2022]
Abstract
Serotonin (5-HT) accumulates in the heart during myocardial ischaemia and induces deleterious effects on the cardiomyocytes. We aimed to investigate whether carrier-mediated 5-HT efflux contributed to the increase in interstitial 5-HT level during ischaemia. Using microdialysis technique applied to the heart of anaesthetised Wistar rats, myocardial interstitial concentration of 5-HT was measured by electro-chemical detection coupled with high-performance liquid chromatography (HPLC-ECD) while simultaneously various pharmacological agents, which create a similar condition to ischaemia, were locally administered by reverse-microdialysis. Sodium cyanide-induced chemical anoxia increased dialysate 5-HT concentration. A similar increase in dialysate 5-HT concentration was induced by ouabain, an inhibitor of sodium-potassium ATPase and reserpine, an inhibitor of vesicular monoamine transporter. Fluoxetine, a selective serotonin reuptake inhibitor raised the baseline level of 5-HT, and neither sodium cyanide nor the combination of ouabain and reserpine induced further increase in 5-HT in the presence of fluoxetine. The results indicate that reverse transport of 5-HT via SERT, which is caused by an impaired ion gradient, contributes to the rise in interstitial level of 5-HT during ischaemia suggesting carrier-mediated 5-HT efflux occurs in the heart in vivo.
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Affiliation(s)
- Takashi Sonobe
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Japan
| | - Tsuyoshi Akiyama
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Japan
| | - James T Pearson
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Japan
- Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, Vic., Australia
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SRC-3 Knockout Attenuates Myocardial Injury Induced by Chronic Intermittent Hypoxia in Mice. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:6372430. [PMID: 34777690 PMCID: PMC8580638 DOI: 10.1155/2021/6372430] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 10/03/2021] [Accepted: 10/13/2021] [Indexed: 12/30/2022]
Abstract
This study investigated the effects of chronic intermittent hypoxia (CIH), a model of sleep apnea syndrome (SAS), on cardiac function. SRC-3 was extremely lowly expressed in the adult mouse heart tissue, while SRC-3 was highly expressed in the adult mouse heart tissue after CIH, suggesting that SRC-3 is involved in CIH model. We further studied the role of SRC-3 in CIH-induced myocardial injury in mice. Twenty-four healthy Balb/c male mice (n = 16, wild type; n = 8, SRC-3 knockout (SRC3-KO)) were randomly divided into three groups: air control (Ctrl), CIH, and CIH+SRC3-KO. Mice were exposed to CIH for 12 weeks. qRT-PCR was used to evaluate cardiac expression of the following genes: 11HSD1, 11HSD2, GR, MR, COX-2, OPN, NOX2, HIF-1-α, IL-1β, IL-6, iNOS, TNF-α, PC-1, and TGF-β. Enzymatic levels of SOD, CAT, MDA, NOS, and NO in the mouse hearts were determined using commercially available kits. Immunohistochemistry (IHC) was used to evaluate NF-κB expression in cardiac tissues. A transmission electron microscope (TEM) was used to evaluate myocardial ultrastructure. TUNEL staining was used to assess myocardial cell apoptosis. CIH induced cardiac damage, which was ameliorated in the SRC-3 KO mice. CIH significantly increased the heart-to-body weight ratio, expression of all aforementioned genes except 11HSD1, GR, and MR, and increased the levels of MDA, NOS, NO, and NF-κB, which were attenuated in the SRC-3 KO mice. The CIH group had the lowest SOD and CAT levels, which were partially recovered in the CIH+SRC3-KO group. 11HSD2 gene expression was elevated in both the CIH and CIH+SRC3-KO groups compared to the Ctrl group. The CIH group had severe myocardial cell apoptosis and mitochondrial dysfunction, which were alleviated in the CIH+SRC3-KO group. CIH causes cardiac damage through inducing oxidative stress and inflammation. Knockout of SRC-3 ameliorates CIH-induced cardiac damage through antagonizing CIH-triggered molecular changes in cardiac tissue.
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Heger J, Hirschhäuser C, Bornbaum J, Sydykov A, Dempfle A, Schneider A, Braun T, Schlüter KD, Schulz R. Cardiomyocytes-specific deletion of monoamine oxidase B reduces irreversible myocardial ischemia/reperfusion injury. Free Radic Biol Med 2021; 165:14-23. [PMID: 33476795 DOI: 10.1016/j.freeradbiomed.2021.01.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/08/2021] [Accepted: 01/10/2021] [Indexed: 01/22/2023]
Abstract
Monoamine oxidase B (MAO-B), a protein localized at the outer mitochondrial membrane, catalyzes the oxidative deamination of biogenic amines thereby producing reactive oxygen species (ROS). Increased ROS formation contributes to myocardial ischemia/reperfusion (I/R); however, the importance of different ROS producing enzymes for increased I/R-induced ROS formation and the subsequent I/R injury is still a matter of debate. Here we describe the first cardiomyocytes-specific MAO-B knockout mouse and test the hypothesis that lack of cardiomyocyte MAO-B protects the heart from I/R injury. A cardiac-specific and tamoxifen-inducible MAO-B knockout mouse (MAO-B KO) was generated using the Cre/lox system; Cre-negative MAO-Bfl/fl littermates served as controls (WT). Lack of MAO-B was verified by Western blot and immunohistochemistry. Cardiac function of MAO-B KO and WT was analyzed by echocardiography, quantification of mitochondrial ROS production, and measurement of myocardial infarct size (in % of ventricle) in hearts exposed to global I/R using the Langendorff technique. MAO-B protein expression was significantly down-regulated in MAO-B KO mice after two weeks of tamoxifen feeding followed by ten weeks of feeding with normal chow. ROS formation stimulated by the MAO-B-specific substrate β-phenylethylamin (PEA; 250 μM) was significantly lower in mitochondria isolated from MAO-B KO compared to WT hearts (WT 4.5 ± 0.8 a. u.; MAO-B KO 1.2 ± 0.3 a. u.). Echocardiography revealed no significant differences in LV dimensions as well as ejection fraction (EF) between WT and MAO-B KO mice (EF: WT 67.3 ± 8.8%; MAO-B KO 67.7 ± 6.5%). After I/R, infarct size was significantly lower in MAO-B KO hearts (WT 69.3 ± 15.1%; MAO-B KO 46.8 ± 12.0%). CONCLUSION: Lack of cardiomyocytes-specific MAO-B reduces infarct size suggesting that MAO-B activity contributes to acute reperfusion injury.
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Affiliation(s)
- Jacqueline Heger
- Justus-Liebig-University Giessen, Physiologisches Institut, Giessen, Germany.
| | | | - Julia Bornbaum
- Justus-Liebig-University Giessen, Physiologisches Institut, Giessen, Germany
| | - Akylbek Sydykov
- Justus-Liebig-University Giessen, Excellence Cluster Cardio-Pulmonary System (ECCPS), Giessen, Germany
| | - Astrid Dempfle
- Universitätsklinikum Schleswig-Holstein, Christian-Albrechts-University Kiel, Institute for Medical Informatics and Statistics, Kiel, Germany
| | - André Schneider
- Max-Planck-Institute for Heart and Lung Research (MPI), Bad Nauheim, Germany
| | - Thomas Braun
- Max-Planck-Institute for Heart and Lung Research (MPI), Bad Nauheim, Germany
| | | | - Rainer Schulz
- Justus-Liebig-University Giessen, Physiologisches Institut, Giessen, Germany
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Comparative Study of Protective Action of Exogenous 2-Cys Peroxiredoxins (Prx1 and Prx2) Under Renal Ischemia-Reperfusion Injury. Antioxidants (Basel) 2020; 9:antiox9080680. [PMID: 32751232 PMCID: PMC7465264 DOI: 10.3390/antiox9080680] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/10/2020] [Accepted: 07/27/2020] [Indexed: 01/09/2023] Open
Abstract
The pathogenesis of ischemia-reperfusion (I/R) injuries is based on oxidative stress caused by a sharp increase in the concentration of free radicals, reactive oxygen species (ROS) and secondary products of free radical oxidation of biological macromolecules during reperfusion. Application of exogenous antioxidants lowers the level of ROS in the affected tissues, suppresses or adjusts the course of oxidative stress, thereby substantially reducing the severity of I/R injury. We believe that the use of antioxidant enzymes may be the most promising line of effort since they possess higher efficiency than low molecular weight antioxidants. Among antioxidant enzymes, of great interest are peroxiredoxins (Prx1–6) which reduce a wide range of organic and inorganic peroxide substrates. In an animal model of bilateral I/R injury of kidneys (using histological, biochemical, and molecular biological methods) it was shown that intravenous administration of recombinant typical 2-Cys peroxiredoxins (Prx1 and Prx2) effectively reduces the severity of I/R damage, contributing to the normalization of the structural and functional state of the kidneys and an almost 2-fold increase in the survival of experimental animals. The use of recombinant Prx1 or Prx2 can be an efficient approach for the prevention and treatment of renal I/R injury.
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12
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Sonobe T, Akiyama T, Du C, Pearson JT. Serotonin uptake via plasma membrane monoamine transporter during myocardial ischemia-reperfusion in the rat heart in vivo. Physiol Rep 2019; 7:e14297. [PMID: 31782271 PMCID: PMC6882957 DOI: 10.14814/phy2.14297] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Serotonin (5-HT) accumulates in the heart during myocardial ischemia and induces deleterious effects on the cardiomyocytes through receptor-dependent and monoamine oxidase-dependent pathways. We aimed to clarify the involvement of extra-neuronal monoamine transporters in the clearance of 5-HT during ischemia and reperfusion in the heart. Using a microdialysis technique in the anesthetized Wistar rat heart, we monitored myocardial interstitial 5-HT and 5-hydroxyindole acetic acid (5-HIAA) concentration by means of electro-chemical detection coupled with high-performance liquid chromatography (HPLC-ECD). Effects of inhibitors of the plasma membrane monoamine transporter (PMAT) and the organic cation transporter 3 (OCT3) (decynium-22 and corticosterone) on the 5-HT and 5-HIAA concentrations during baseline, coronary occlusion, and reperfusion were investigated. Basal dialysate 5-HT concentration were increased by local administration of decynium-22, but not by corticosterone. Addition of fluoxetine, a serotonin transporter (SERT) inhibitor further increased the 5-HT concentration upon during administration of decynium-22. Decynium-22 elevated the background level of 5-HT during coronary occlusion and maintained 5-HT concentration at a high level during reperfusion. Production of 5-HIAA in the early reperfusion was significantly suppressed by decynium-22. These results indicate that PMAT and SERT independently regulate basal level of interstitial 5-HT, and PMAT plays a more important role in the clearance of 5-HT during reperfusion. These data suggest the involvement of PMAT in the monoamine oxidase-dependent deleterious pathway in the heart.
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Affiliation(s)
- Takashi Sonobe
- Department of Cardiac PhysiologyNational Cerebral and Cardiovascular Center Research InstituteSuitaOsakaJapan
| | - Tsuyoshi Akiyama
- Department of Cardiac PhysiologyNational Cerebral and Cardiovascular Center Research InstituteSuitaOsakaJapan
| | - Cheng‐Kun Du
- Department of Cardiac PhysiologyNational Cerebral and Cardiovascular Center Research InstituteSuitaOsakaJapan
| | - James T. Pearson
- Department of Cardiac PhysiologyNational Cerebral and Cardiovascular Center Research InstituteSuitaOsakaJapan
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Ishikawa Y, Kitagawa H, Sawada T, Seto T, Takahashi K, Yamazaki T. Deuterium oxide protects against myocardial injury induced by ischemia and reperfusion in rats. SCAND CARDIOVASC J 2019; 53:329-336. [PMID: 31455109 DOI: 10.1080/14017431.2019.1657939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Objectives. Although deuterium oxide (D2O) has preservative property on the extracted organ, whether D2O also protects the in situ myocardial injury remains unknown. Using cardiac microdialysis, local administration of D2O through dialysis probe was applied in situ rat heart. We examined the effect of the D2O on the myocardial injury induced ischemia, reperfusion, and chemical hypoxia. Methodology. We measured dialysate myoglobin levels during 30 min of coronary occlusion and reperfusion in the absence and presence of D2O. Furthermore, to confirm the effect of D2O on NaCN induced myocardial injury, we measured the dialysate myoglobin levels with local perfusion of NaCN in the absence and presence of D2O. Results. The dialysate myoglobin levels increased from 177 ± 45 ng/mL at baseline to 3030 ± 1523 ng/mL during 15-30 min of coronary occlusion and further increased to 8588 ± 1684ng/mL at 0-15 min of reperfusion. The dialysate myoglobin levels with 60 min local perfusion of NaCN increased to 1214 ± 279 ng/mL. D2O attenuated myocardial myoglobin release during 15-30 min of coronary occlusion and 0-30 min of reperfusion and 15-60 min of local perfusion of NaCN. Conclusions. D2O might have a beneficial effect of myocardium against ischemia, reperfusion and chemical hypoxia.
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Affiliation(s)
- Yuko Ishikawa
- Department of Anesthesiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Hirotoshi Kitagawa
- Department of Anesthesiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Tadashi Sawada
- Department of Anesthesiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Tomoyoshi Seto
- Department of Anesthesiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Kan Takahashi
- Department of Anesthesiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Toji Yamazaki
- Department of Anesthesiology, Shiga University of Medical Science, Otsu, Shiga, Japan
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14
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Hydrogen and Oxygen Mixture to Improve Cardiac Dysfunction and Myocardial Pathological Changes Induced by Intermittent Hypoxia in Rats. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:7415212. [PMID: 30984338 PMCID: PMC6431505 DOI: 10.1155/2019/7415212] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 12/11/2018] [Accepted: 01/23/2019] [Indexed: 12/25/2022]
Abstract
Obstructive sleep apnea (OSA) can cause intermittent changes in blood oxygen saturation, resulting in the generation of many reactive oxygen species (ROS). To discover new antioxidants and clarify the endoplasmic reticulum (ER) stress involved in cardiac injury in OSA, we established a chronic intermittent hypoxia (CIH) rat model with a fraction of inspired O2 (FiO2) ranging from 21% to 9%, 20 times/h for 8 h/day, and the rats were treated with H2-O2 mixture (67% hydrogen and 33% oxygen) for 2 h/day for 35 days. Our results showed that H2-O2 mixture remarkably improved cardiac dysfunction and myocardial fibrosis. We found that H2-O2 mixture inhalation declined ER stress-induced apoptosis via three major response pathways: PERK-eIF2α-ATF4, IRE 1-XBP1, and ATF 6. Furthermore, we revealed that H2-O2 mixture blocked c-Jun N-terminal kinase- (JNK-) MAPK activation, increased the ratio of Bcl-2/Bax, and inhibited caspase 3 cleavage to protect against CIH-induced cardiac apoptosis. In addition, H2-O2 mixture considerably decreased ROS levels via upregulating superoxide dismutase (SOD) and glutathione (GSH) as well as downregulating NADPH oxidase (NOX 2) expression in the hearts of CIH rats. All the results demonstrated that H2-O2 mixture significantly reduced ER stress and apoptosis and that H2 might be an efficient antioxidant against the oxidative stress injury induced by CIH.
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15
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Emerging role of monoamine oxidase as a therapeutic target for cardiovascular disease. Curr Opin Pharmacol 2017; 33:64-69. [PMID: 28528298 DOI: 10.1016/j.coph.2017.04.003] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 03/28/2017] [Accepted: 04/19/2017] [Indexed: 11/23/2022]
Abstract
In the past decade, accumulating evidence highlighted the role of monoamine oxidases (MAOs) in cardiovascular disease (CVD). MAOs are flavoenzymes located in the outer mitochondrial membrane, responsible for the degradation of neurotransmitters and biogenic amines. During this process they generate hydrogen peroxide, aldehydes and ammonia, species that can target mitochondria and induce mitochondrial dysfunction and cardiomyocyte death. Indeed, MAO inhibition affords cardioprotection in several models of CVD, such as ischemia/reperfusion, heart failure and diabetes. Importantly, a few studies provided encouraging results suggesting that MAO inhibition might be beneficial also in patients with CVD. Thus, selective and reversible MAO inhibitors, currently used as therapy for depression and neurodegenerative disorders, might be considered as candidate drugs for the treatment of CVD.
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16
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Retinal Diseases Associated with Oxidative Stress and the Effects of a Free Radical Scavenger (Edaravone). OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:9208489. [PMID: 28194256 PMCID: PMC5286467 DOI: 10.1155/2017/9208489] [Citation(s) in RCA: 149] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 12/20/2016] [Indexed: 02/07/2023]
Abstract
Oxidative stress plays a pivotal role in developing and accelerating retinal diseases including age-related macular degeneration (AMD), glaucoma, diabetic retinopathy (DR), and retinal vein occlusion (RVO). An excess amount of reactive oxygen species (ROS) can lead to functional and morphological impairments in retinal pigment epithelium (RPE), endothelial cells, and retinal ganglion cells (RGCs). Here we demonstrate that edaravone, a free radical scavenger, decreased apoptotic cell death, oxidative damage to DNA and lipids, and angiogenesis through inhibiting JNK and p38 MAPK pathways in AMD, glaucoma, DR, and RVO animal models. These data suggest that the therapeutic strategy for targeting oxidative stress may be important for the treatment of these ocular diseases, and edaravone may be useful for treating retinal diseases associated with oxidative stress.
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Abstract
Ischemic disorders, such as myocardial infarction, stroke, and peripheral vascular disease, are the most common causes of debilitating disease and death in westernized cultures. The extent of tissue injury relates directly to the extent of blood flow reduction and to the length of the ischemic period, which influence the levels to which cellular ATP and intracellular pH are reduced. By impairing ATPase-dependent ion transport, ischemia causes intracellular and mitochondrial calcium levels to increase (calcium overload). Cell volume regulatory mechanisms are also disrupted by the lack of ATP, which can induce lysis of organelle and plasma membranes. Reperfusion, although required to salvage oxygen-starved tissues, produces paradoxical tissue responses that fuel the production of reactive oxygen species (oxygen paradox), sequestration of proinflammatory immunocytes in ischemic tissues, endoplasmic reticulum stress, and development of postischemic capillary no-reflow, which amplify tissue injury. These pathologic events culminate in opening of mitochondrial permeability transition pores as a common end-effector of ischemia/reperfusion (I/R)-induced cell lysis and death. Emerging concepts include the influence of the intestinal microbiome, fetal programming, epigenetic changes, and microparticles in the pathogenesis of I/R. The overall goal of this review is to describe these and other mechanisms that contribute to I/R injury. Because so many different deleterious events participate in I/R, it is clear that therapeutic approaches will be effective only when multiple pathologic processes are targeted. In addition, the translational significance of I/R research will be enhanced by much wider use of animal models that incorporate the complicating effects of risk factors for cardiovascular disease. © 2017 American Physiological Society. Compr Physiol 7:113-170, 2017.
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Affiliation(s)
- Theodore Kalogeris
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri, USA
| | - Christopher P. Baines
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri, USA
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA
- Department of Biomedical Sciences, University of Missouri College of Veterinary Medicine, Columbia, Missouri, USA
| | - Maike Krenz
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri, USA
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA
| | - Ronald J. Korthuis
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri, USA
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA
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18
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Du CK, Zhan DY, Akiyama T, Inagaki T, Shishido T, Shirai M, Pearson JT. Myocardial interstitial levels of serotonin and its major metabolite 5-hydroxyindole acetic acid during ischemia-reperfusion. Am J Physiol Heart Circ Physiol 2016; 312:H60-H67. [PMID: 27793854 DOI: 10.1152/ajpheart.00471.2016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 10/07/2016] [Accepted: 10/26/2016] [Indexed: 11/22/2022]
Abstract
The aim of this study was to examine the accumulation of serotonin (5-HT) and degradation of 5-HT taken up into cells in the ischemic region during myocardial ischemia-reperfusion. Using microdialysis technique in anesthetized rats, we monitored myocardial interstitial levels of 5-HT and its metabolite produced by monoamine oxidase (MAO), 5-hydroxyindole acetic acid (5-HIAA), during 30-min coronary occlusion followed by 45-min reperfusion, and investigated the effects of local administration of the MAO inhibitor pargyline and the 5-HT uptake inhibitor fluoxetine. In the vehicle group, the dialysate 5-HT concentration increased from 1.3 ± 0.2 nM at baseline to 29.6 ± 2.8 nM at 22.5-30 min of occlusion, but the dialysate 5-HIAA concentration did not change from baseline (9.9 ± 1.1 nM). Upon reperfusion, the dialysate 5-HT concentration increased further to a peak (34.2 ± 4.2 nM) at 0-7.5 min and then declined. The dialysate 5-HIAA concentration increased to 31.9 ± 5.2 nM at 7.5-15 min of reperfusion and maintained this high level until 45 min. Pargyline markedly suppressed the increase in dialysate 5-HIAA concentration after reperfusion and increased the averaged dialysate 5-HT concentration during the reperfusion period. Fluoxetine suppressed the increase in dialysate 5-HT concentration during occlusion but did not change dialysate 5-HT or 5-HIAA concentration after reperfusion. During ischemia, 5-HT secreted from ischemic tissues accumulates but 5-HT degradation by MAO is suppressed. After reperfusion, degradation of 5-HT taken up into cells is enhanced and contributes to the clearance of accumulated 5-HT. This degradation following cellular uptake is dependent on MAO activity but not the fluoxetine-sensitive uptake transporter. NEW & NOTEWORTHY By monitoring myocardial interstitial levels of 5-HT and its metabolite, 5-hydroxyindole acetic acid, we investigated 5-HT kinetics during myocardial ischemia-reperfusion. 5-HT accumulates but 5-HT degradation is suppressed during ischemia. After reperfusion, 5-HT degradation is enhanced and this degradation is dependent on monoamine oxidase activity but not fluoxetine-sensitive uptake transporter.
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Affiliation(s)
- Cheng-Kun Du
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan; and
| | - Dong-Yun Zhan
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan; and
| | - Tsuyoshi Akiyama
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan; and
| | - Tadakatsu Inagaki
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan; and
| | - Toshiaki Shishido
- Department of Research Promotion, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - Mikiyasu Shirai
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan; and
| | - James T Pearson
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan; and
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