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Rivera-Mancía S, Tristán-López L, Hernández-Díaz K, Rivera-Espinosa L, Ríos C, Montes S. In vitro inhibition of brain phosphate-activated glutaminase by ammonia and manganese. J Trace Elem Med Biol 2020; 62:126625. [PMID: 32717575 DOI: 10.1016/j.jtemb.2020.126625] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/07/2020] [Accepted: 06/11/2020] [Indexed: 12/26/2022]
Abstract
INTRODUCTION As a consequence of the loss of liver function in chronic liver disease, increased levels of ammonia, manganese, and glutamine have been observed in the brain of hepatic encephalopathy patients. OBJECTIVE In the present study, we explored phosphate activated glutaminase (PAG) activity in mitochondrial enriched fractions under treatment with ammonia and manganese. METHODS We dissected out the brain cortex, striatum, and cerebellum of male Wistar rats 250-280 g weight; brain sections were pooled to obtain enriched mitochondrial fractions by differential centrifugation. Aliquots equivalent to 200 μg of protein were incubated with semi-log increasing concentrations of ammonia and/or manganese both as chloride salts (from 0 to 10 000 μM) and glutamine (4 mM) for 30 min. Then, the glutamate produced by the reaction was determined by HPLC coupled with fluorescence detection. RESULTS AND DISCUSSION Both manganese and ammonia inhibited PAG in a concentration-dependent manner. Non-linear modeling was used to determine IC50 and IC20 for ammonia (120 μM) and manganese (2 mM). We found that PAG activity under the combination of IC20 of ammonia and manganese was equivalent to the sum of the effects of both substances, being PAG inhibition more pronounced in mitochondrial fractions from cerebellum. The PAG inhibition observed here could potentially explain a pathway for glutamine accumulation, by means of the inhibition of PAG activity as a consequence of increased concentrations of manganese and ammonia in the brain under liver damage conditions.
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Affiliation(s)
- Susana Rivera-Mancía
- CONACYT- National Institute of Cardiology "Ignacio Chávez", Juan Badiano 1, Sección XVI, Tlalpan, CDMX, 14080, Mexico
| | - Luis Tristán-López
- Neurochemistry Department, National Institute of Neurology and Neurosurgery "Manuel Velasco Suárez", Insurgentes sur 3877, La Fama, Tlalpan, CDMX, 14269, Mexico
| | - Karen Hernández-Díaz
- Neurochemistry Department, National Institute of Neurology and Neurosurgery "Manuel Velasco Suárez", Insurgentes sur 3877, La Fama, Tlalpan, CDMX, 14269, Mexico
| | - Liliana Rivera-Espinosa
- Pharmacology Department, National Institute of Pediatrics, Iman Avenue 1, Insurgentes Cuicuilco, Coyoacán, CDMX, 04530, Mexico
| | - Camilo Ríos
- Neurochemistry Department, National Institute of Neurology and Neurosurgery "Manuel Velasco Suárez", Insurgentes sur 3877, La Fama, Tlalpan, CDMX, 14269, Mexico
| | - Sergio Montes
- Neurochemistry Department, National Institute of Neurology and Neurosurgery "Manuel Velasco Suárez", Insurgentes sur 3877, La Fama, Tlalpan, CDMX, 14269, Mexico.
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Cadmium exposure negatively affects the microarchitecture of trabecular bone and decreases the density of a subset of sympathetic nerve fibers innervating the developing rat femur. Biometals 2020; 34:87-96. [PMID: 33145678 DOI: 10.1007/s10534-020-00265-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 10/27/2020] [Indexed: 10/23/2022]
Abstract
Cadmium (Cd) is toxic to the skeletal system resulting in bone loss and pain. We aimed at determining the effect of chronic Cd exposure on bone density and microarchitecture along with changes in the density of a subset of sensory and sympathetic nerve fibers innervating the developing rat femur. Newborn male Wistar rats were injected daily for 49 days with CdCl2 (1 mg/kg i.p.) or saline solution (control group). At the day of sacrifice, levels of Cd in the right femur, liver and kidney were determined by atomic absorption spectrophotometry. Additionally, microCT followed by immunohistochemical analyses were performed in the left femur. Results showed Cd accumulation in trabecular bone neared levels seen in liver and kidney. Cd concentration in cortical bone was significantly lower versus trabecular bone. MicroCT analysis revealed that Cd-exposed rats had a significant decrease in trabecular bone parameters at the distal femoral metaphysis; however, most of the cortical bone parameters were not significantly affected. Cd-exposed rats showed a significant loss of TH+ sympathetic nerve fibers, but not of CGRP+ sensory nerve fibers, at the level of bone marrow of the femoral diaphysis as compared to control rats. This study shows that Cd negatively affects bone density and microarchitecture of trabecular bone and decreases the density of sympathetic nerve fibers innervating rat femur. Future studies are warranted to determine the toxigenic mechanisms of Cd on sympathetic nerves and how sympathetic denervation influences bone loss in animals exposed to Cd.
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Montes S, Castro-Chávez A, Florian-Soto C, Heras-Romero Y, Ríos C, Rivera-Mancía S. Bumetanide increases manganese accumulation in the brain of rats with liver damage. Eur J Pharmacol 2016; 774:127-34. [DOI: 10.1016/j.ejphar.2016.02.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 01/26/2016] [Accepted: 02/03/2016] [Indexed: 11/30/2022]
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Çelik MS, Güven K, Akpolat V, Akdağ MZ, Nazıroğlu M, Gül-Güven R, Çelik MY, Erdoğan S. Extremely low-frequency magnetic field induces manganese accumulation in brain, kidney and liver of rats. Toxicol Ind Health 2013; 31:576-80. [DOI: 10.1177/0748233713480204] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The aim of the present study was to determine the effects of extremely low-frequency magnetic field (ELF-MF) on accumulation of manganese (Mn) in the kidney, liver and brain of rats. A total of 40 rats were randomly divided into eight groups. Four control groups received 0, 3.75, 15 and 60 mg Mn per kg body weight orally every 2 days for 45 days, respectively. The remaining four groups received same concentrations of Mn and were also exposed to ELF-MF (1.5 mT; 50 Hz) for 4 h for 5 days a week during 45 days. Following the last exposure, kidney, liver and brain were taken from all rats and they were analyzed for Mn accumulation levels using an inductively coupled plasma-optical emission spectrometer. In result of the current study, we observed that Mn levels in brain, kidney and liver were higher in Mn groups than in control groups. Mn levels in brain, kidney and liver were also higher in Mn plus ELF-MF groups than in Mn groups. In conclusion, result of the current study showed that the ELF-MF induced manganese accumulation in kidney, liver and brain of rats.
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Affiliation(s)
- Mustafa Salih Çelik
- Department of Biophysics, Faculty of Medicine, Dicle University, Diyarbakir, Turkey
| | - Kemal Güven
- Department of Biology, Faculty of Science, Dicle University, Diyarbakir, Turkey
| | - Veysi Akpolat
- Department of Biophysics, Faculty of Medicine, Dicle University, Diyarbakir, Turkey
| | - Mehmet Zulkuf Akdağ
- Department of Biophysics, Faculty of Medicine, Dicle University, Diyarbakir, Turkey
| | - Mustafa Nazıroğlu
- Department of Biophysics, Faculty of Medicine, Suleyman Demirel University, Isparta, Turkey
| | - Reyhan Gül-Güven
- Science Teaching Program, Primary Education Department, Faculty of Ziya Gokalp Education, Diyarbakir, Turkey
| | - M Yusuf Çelik
- Department of Biostatics, Faculty of Medicine, Dicle University, Diyarbakir, Turkey
| | - Sait Erdoğan
- Department of Chemistry, Faculty of Science, Dicle University, Diyarbakir, Turkey
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Manganese and ammonia interactions in the brain of cirrhotic rats: effects on brain ammonia metabolism. Neurochem Res 2012; 37:1074-84. [PMID: 22290316 DOI: 10.1007/s11064-012-0710-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 01/13/2012] [Accepted: 01/18/2012] [Indexed: 01/18/2023]
Abstract
Hepatic encephalopathy is a major complication of cirrhosis. Ammonia and manganese have been associated with hepatic encephalopathy underlying mechanisms. Motor impairment and brain edema are common signs of hepatic encephalopathy. In the present study a model of liver damage in rats was combined with ammonia and manganese exposure to evaluate the role of these substances separately and their interactions on brain glutamine, water content and motor coordination. Additionally, we explored brain levels of each substance -Mn and ammonia- in the presence or absence of the other. Liver damage was induced by bile duct ligation. Rats were exposed to MnCl2 in drinking water (1 mg Mn/ml) and to ammonia in chow pellets containing 20% ammonium acetate (w/w). As expected, manganese and ammonia levels increased in the brain of cirrhotic rats exposed to these substances; in these animals, glutamine brain levels also increased and positively correlated with tissue water content in cortex. A three way-ANOVA showed that manganese favored ammonia and glutamine accumulation in brain, and possibly their subsequent deleterious effects, as evidenced by the fact that manganese and ammonia accumulation in the brain of cirrhotic rats severely affected motor function. These results suggest that even when controlling ammonia levels in cirrhotic patients, reduction of manganese intake is also a potential strategy to be considered in clinical practice.
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Rivera-Mancía S, Montes S, Méndez-Armenta M, Muriel P, Ríos C. Morphological changes of rat astrocytes induced by liver damage but not by manganese chloride exposure. Metab Brain Dis 2009; 24:243-55. [PMID: 19353255 DOI: 10.1007/s11011-009-9138-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Accepted: 09/03/2008] [Indexed: 11/29/2022]
Abstract
Liver cirrhosis is a common cause of death around the world. One of its more severe complications is hepatic encephalopathy. As a consequence of liver impairment, manganese (Mn) and other substances accumulate in the brain. Astrocytic morphological changes have been found in postmortem brains of cirrhotic patients. In this study we used a model of cirrhosis induced by bile duct ligation and Mn accumulation by exposing rats to MnCl(2) (1 mg Mn/ml) in their drinking water. Four experimental groups were used: Sham, Sham plus Mn treatment, BDL (bile duct ligated) and BDL plus Mn treatment. Brain Mn was measured by atomic absorption spectrophotometry in cortex, striatum and globus pallidus. Altered and normal astrocytes were counted in the same brain areas. Brain Mn was highest in rats of the BDLMn group. An increased number of altered astrocytes was found only in BDL groups, Mn did not modify this effect. No changes were found in the total number of astrocytes. According to our results, biliary obstruction induced an increase in the number of altered astrocytes since early stages of cirrhosis and Mn did not affect this effect.
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Affiliation(s)
- Susana Rivera-Mancía
- Departamento de Neuroquímica, Instituto Nacional de Neurología y Neurocirugía, Manuel Velasco Suárez, México D.F, México
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Montes S, Riojas-Rodríguez H, Sabido-Pedraza E, Ríos C. Biomarkers of manganese exposure in a population living close to a mine and mineral processing plant in Mexico. ENVIRONMENTAL RESEARCH 2008; 106:89-95. [PMID: 17915211 DOI: 10.1016/j.envres.2007.08.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2006] [Revised: 08/15/2007] [Accepted: 08/17/2007] [Indexed: 05/17/2023]
Abstract
Manganese (Mn) is considered an essential metal; nevertheless, excessive Mn exposure in humans is known to affect central nervous system. Mn access to its toxic target, the brain, is a complex phenomenon subject to physiological and physiopathological processes; in which, among others, the route of exposure plays an important role. Mn airborne exposure has gained interest both in occupational and environmental studies in order to understand the effects of low-level, long-term exposure. The objective of the present study was to describe the relationship between blood Mn and prolactin as marker of effect exposure, as well as other variables from subjects dwelling in a mining district in central Mexico environmentally exposed to the metal. This study was conducted on 230 volunteers; blood samples were obtained from cubital vein and hemoglobin, prolactin, lead (Pb), and Mn levels were measured. Non-parametrical Spearman's correlation showed statistical associations between blood and Mn levels and prolactin (rho=0.197), hemoglobin (rho= -0.213), age (rho= -0.186), and blood lead (rho= -0.167). Multiple regression analysis showed that blood Mn levels as an important factor to determine serum prolactin levels (beta=0.111, p=0.029) in a model corrected by gender and age. Results suggest that assessment of Mn exposure by biomarkers on general population is complex due to the variability and characteristics of the metal; however, specific subpopulations such as iron-deficient individuals are suspected to accumulate Mn in blood and thus they may be susceptible to the neurotoxic effects of Mn.
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Affiliation(s)
- Sergio Montes
- Departamento de Neuroquímica, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, Insurgentes Sur 3877, La Fama, Tlalpan, Mexico city, México
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Sánchez-Salgado JC, Ortiz-Andrade RR, Aguirre-Crespo F, Vergara-Galicia J, León-Rivera I, Montes S, Villalobos-Molina R, Estrada-Soto S. Hypoglycemic, vasorelaxant and hepatoprotective effects of Cochlospermum vitifolium (Willd.) Sprengel: a potential agent for the treatment of metabolic syndrome. JOURNAL OF ETHNOPHARMACOLOGY 2007; 109:400-5. [PMID: 16978815 DOI: 10.1016/j.jep.2006.08.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2006] [Revised: 07/10/2006] [Accepted: 08/11/2006] [Indexed: 05/11/2023]
Abstract
Cochlospermum vitifolium (Willd.) Sprengel is a Mexican medicinal plant that is used in the folk medicine for the treatment of hypertension, diabetes, hepatitis and related diseases. The purpose of the present study was to assess the pharmacological properties of different extracts from Cochlospermum vitifolium bark as potential agent for the treatment of some factors related with metabolic syndrome (MS), a complex disease produced for several pathophysiological factors such as visceral fat obesity, insulin resistance, hypertension, dyslipidemia and liver steatosis. Hexane (HECv), dichloromethane (DECv) and methanol (MECv) extracts were subjected to some pharmacological assays to determine their vasorelaxant and hypoglycemic activity. On the other hand, MECv was also evaluated to determine its hepatoprotective effect on sub-chronic experimental assay. HECv showed a significant endothelium-independent relaxation on rat aorta rings (intact endothelium: IC(50)=14.42+/-5.90 microg/mL, E(max)=92.71+/-8.9%; denuded endothelium: IC(50)=27.94+/-4.0 microg/mL, E(max)=78.68+/-4.6%) and MECv produced an endothelium-dependent relaxation (IC(50)=21.94+/-6.87 microg/mL, E(max)=79.12+/-7.80%) on this tissue. Furthermore, HECv (at a dose of 120 mg/kg) also showed a significant decrease of blood glucose levels (p<0.05) on normoglycemic rats. Moreover, MECv (at a dose of 100 mg/kg) also was administered to bile duct-obstructed rats to determine its hepatoprotective activity, showing a statistically significant decrease of serum glutamic-pyruvic transaminase (PGT, 45%) and alkaline phosphatase (APh, 15%) (p<0.05). Finally, we obtained a crystalline polyphenolic compound from MECv by spontaneous precipitation. Those crystals were identified as (+/-)-naringenin by X-ray diffraction, NMR, IR and GC-MS techniques. Results suggest that Cochlospermum vitifolium could be used as a potential agent against MS since it shows hypoglycemic, vasorelaxant and hepatoprotective properties.
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Affiliation(s)
- J C Sánchez-Salgado
- Facultad de Farmacia, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001 Col. Chamilpa, 62210 Cuernavaca, Morelos, Mexico
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Gulyás B, Dobai J, Szilágyi G, Csécsei G, Székely G. Nitric oxide production in striatum and pallidum of cirrhotic rats. Neurochem Res 2006; 31:157-66. [PMID: 16673175 DOI: 10.1007/s11064-005-9005-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/06/2005] [Indexed: 10/25/2022]
Abstract
Ammonium and manganese are neurotoxic agents related to brain metabolic disturbances observed after prolonged liver damage. The aim of this study was to assess the production of nitric oxide (NO) in the brain of cirrhotic rats exposed to manganese. We induced cirrhosis by bile duct ligation for 4 weeks in rats. From brain, striatum and globus pallidus were dissected out, and NO synthase activity and the content of nitrites plus nitrates (NOx) were determined. In pallidum we found a diminished constitutive NO synthase activity from cirrhotic rats, independently of manganese exposure. This result was confirmed by low levels of NOx in the same brain area (P<0.05, two-way ANOVA). This finding was not related to protein expression of NO synthase since no differences were observed in immunoblot signals between cirrhotic and sham-operated animals. Results from present study suggest that the production of NO is reduced in basal ganglia during cirrhosis.
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Affiliation(s)
- B Gulyás
- Department of Neuroscience, Karolinska Institute, S-171 77, Stockholm, Sweden.
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Montes S, Alcaraz-Zubeldia M, Muriel P, Rios C. Role of manganese accumulation in increased brain glutamine of the cirrhotic rat. Neurochem Res 2003; 28:911-7. [PMID: 12718445 DOI: 10.1023/a:1023279527545] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cirrhosis promotes increases of both manganese and glutamine in brain. Manganese is a modulator and glutamine is the product of glutamine synthetase. This work studies the relationship between manganese and glutamine synthetase in a model of cirrhosis in the rat. We administered manganese (1 g/L) in the drinking water of sham-operated and bile-duct obstructed rats. We evaluated the manganese and glutamine accumulation and the glutamine synthetase activity in frontal cortex, striatum, and pallidum after 2, 4, and 6 weeks of biliary obstruction or sham surgery. Cirrhotic rats receiving manganese increased their brain content of metal about 400%-600% after 4 weeks of treatment (P < .05) and also remarkably accumulated glutamine through time in the three regions studied (P < .05 at week 6). Interestingly, bile-duct obstructed rats treated with manganese showed no effect on glutamine synthetase activity. Results from this study suggest that manganese induces increases of brain glutamine independently of its synthesis.
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Affiliation(s)
- Sergio Montes
- Departamento de Neuroquímica, Instituto Nacional de Neurología y, Neurocirugía "Manuel Velasco Suárez", Mexico
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