1
|
Hypotensive effects of melatonin in rats: Focus on the model, measurement, application, and main mechanisms. Hypertens Res 2022; 45:1929-1944. [PMID: 36123396 DOI: 10.1038/s41440-022-01031-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 08/23/2022] [Accepted: 08/25/2022] [Indexed: 11/08/2022]
Abstract
The hypotensive effects of melatonin are based on a negative correlation between melatonin levels and blood pressure in humans. However, there is a positive correlation in nocturnal animals that are often used as experimental models in cardiovascular research, and the hypotensive effects and mechanism of melatonin action are often investigated in rats and mice. In rats, the hypotensive effects of melatonin have been studied in normotensive and spontaneously or experimentally induced hypertensive strains. In experimental animals, blood pressure is often measured indirectly during the light (passive) phase of the day by tail-cuff plethysmography, which has limitations regarding data quality and animal well-being compared to telemetry. Melatonin is administered to rats in drinking water, subcutaneously, intraperitoneally, or microinjected into specific brain areas at different times. Experimental data show that the hypotensive effects of melatonin depend on the experimental animal model, blood pressure measurement technique, and the route, time and duration of melatonin administration. The hypotensive effects of melatonin may be mediated through specific membrane G-coupled receptors located in the heart and arteries. Due to melatonin's lipophilic nature, its potential hypotensive effects can interfere with various regulatory mechanisms, such as nitric oxide and reactive oxygen species production and activation of the autonomic nervous and circadian systems. Based on the research conducted on rats, the cardiovascular effects of melatonin are modulatory, delayed, and indirect.
Collapse
|
2
|
Nugent WH, Carr DA, Macko AR, Song BK. Physiological and microvascular responses to hemoglobin concentration-targeted hemolytic anemia in rats. J Appl Physiol (1985) 2020; 128:1579-1586. [PMID: 32378976 DOI: 10.1152/japplphysiol.00767.2019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hemolytic anemia (HA) is reduced blood oxygen-carrying capacity resulting from the depletion of red blood cells. Treatment for severe cases involves transfusion to improve oxygen delivery (Do2), which carries risk. In humans, a total hemoglobin (tHb) concentration of 8 g/dL is severe, and <7 g/dL indicates transfusion. Some evidence suggests that compensatory mechanisms maintaining Do2 are not compromised until <5 g/dL rendering transfusion at 7 g/dL premature. A Sprague-Dawley rat model of phenylhydrazine-induced HA was assessed over decreasing tHb for a Do2 decompensation point. Three groups (100, 50, or 25% tHb, equating to 16.4, 7.4, or 3.2 g/dL) were generated. Cardiopulmonary, blood chemistry, and oxygenation parameters were measured under anesthesia. Vasoconstrictive responsiveness to phenylephrine was assessed in the exteriorized spinotrapezius. For 50% tHb, cardiopulmonary parameters, Do2, and lactate levels were similar to those for 100% tHb. Enhanced vasoconstriction occurred with 50% tHb (P < 0.0001), not 25% tHb. The 25% group showed decreases in cardiopulmonary parameters, Do2, and lactate levels compared with the 100% and 50% groups (P < 0.05). Do2 showed a positive correlation with lactate levels at 25% tHb, but decompensation, defined by peripheral hypoxia, was not reached. This is the first study relating Do2 to tHb in rats. A 50% reduction in tHb was supported by vascular compensation, whereas 25% tHb levied the cardiopulmonary system. A decompensation point was not identified. A rising need for treatment as tHb levels decline below 8 g/dL is evident, but, as compensatory mechanisms remain intact as tHb approaches 3.2 g/dL in rats, a transfusion limit of 5 g/dL in healthy patients is supported.NEW & NOTEWORTHY Early, chronic compensation to severe hemolytic anemia is vascular, switching to cardiopulmonary support as hemoglobin levels decline. Oxygen delivery does not correlate with serum lactate level until total hemoglobin is reduced by 75%.
Collapse
Affiliation(s)
- William H Nugent
- Song Biotechnologies, Limited Liability Company, Baltimore, Maryland
| | - Danuel A Carr
- Song Biotechnologies, Limited Liability Company, Baltimore, Maryland
| | - Antoni R Macko
- Song Biotechnologies, Limited Liability Company, Baltimore, Maryland
| | - Bjorn K Song
- Song Biotechnologies, Limited Liability Company, Baltimore, Maryland
| |
Collapse
|
3
|
Lee WJ, Chen LC, Lin JH, Cheng TC, Kuo CC, Wu CH, Chang HW, Tu SH, Ho YS. Melatonin promotes neuroblastoma cell differentiation by activating hyaluronan synthase 3-induced mitophagy. Cancer Med 2019; 8:4821-4835. [PMID: 31274246 PMCID: PMC6712479 DOI: 10.1002/cam4.2389] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 06/17/2019] [Accepted: 06/18/2019] [Indexed: 12/20/2022] Open
Abstract
Neuroblastoma is the second most common pediatric malignancy and has a high rate of spontaneous remission. Uncovering the mechanisms underlying neuroblastoma cell differentiation is critical for therapeutic purposes. A neuroblastoma cell line (N2a) treated with either serum withdrawal (<2.5%) or melatonin (>0.1 nmol/L) for 24 hours was used as a cell differentiation research model. Interestingly, the hyaluronan synthase 3 (HAS3) protein was induced in differentiated N2a cells. N2a-allografted nude mice received an intraperitoneal injection of melatonin (40 or 80 mg/kg/day for 3 weeks). The mean tumor volume in mice treated with 80 mg/kg melatonin was smaller than that in PBS-treated mice (1416.3 and 3041.3 mm3 , respectively, difference = 1625 mm3 , *P = 0.0003, n = 7 per group). Compared with the vector control group, N2a cells with forced HAS3 overexpression showed significantly increased neuron length (*P = 0.00082) and neurite outgrowth (*P = 0.00059). Intracellular changes in autophagy, including distorted mitochondria with abnormal circular inner membranes, were detected by transmission electron microscopy (TEM). Our study demonstrated that HAS3-mediated signaling activated by physiological concentrations of melatonin (>0.1 nmol/L) triggered significant N2a cell differentiation. These results provide molecular data with potential clinical relevance for therapeutic drug development.
Collapse
Affiliation(s)
- Wen-Jui Lee
- Ph.D. Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University and National Health Research Institutes, Taipei, Taiwan
| | - Li-Ching Chen
- Division of Breast Surgery, Department of Surgery, Taipei Medical University Hospital, Taipei, Taiwan.,Taipei Cancer Center, Taipei Medical University, Taipei, Taiwan.,TMU Research Center of Cancer Translational Medicine, Taipei Medical University, Taipei, Taiwan
| | - Juo-Han Lin
- Ph.D. Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei, Taiwan
| | - Tzu-Chun Cheng
- School of Medical Laboratory Science and Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Ching-Chuan Kuo
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, Taiwan
| | - Chih-Hsiung Wu
- Department of Surgery, En Chun Kong Hospital, New Taipei City, Taiwan.,Department of Surgery, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Hui-Wen Chang
- Department of Laboratory Medicine, Taipei Medical University Hospital, Taipei, Taiwan
| | - Shih-Hsin Tu
- Division of Breast Surgery, Department of Surgery, Taipei Medical University Hospital, Taipei, Taiwan.,Taipei Cancer Center, Taipei Medical University, Taipei, Taiwan.,Department of Surgery, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yuan-Soon Ho
- TMU Research Center of Cancer Translational Medicine, Taipei Medical University, Taipei, Taiwan.,School of Medical Laboratory Science and Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.,Department of Laboratory Medicine, Taipei Medical University Hospital, Taipei, Taiwan.,Graduate Institute of Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.,Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| |
Collapse
|
4
|
Fontana J, Zima M, Vetvicka V. Biological Markers of Oxidative Stress in Cardiovascular Diseases: After so Many Studies, What do We Know? Immunol Invest 2018; 47:823-843. [DOI: 10.1080/08820139.2018.1523925] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Josef Fontana
- Center for Research on Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Michal Zima
- Department of Bioenergetics, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Vaclav Vetvicka
- Department of Pathology, University of Louisville, Louisville, KY USA
| |
Collapse
|