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Chiu HC, Yang RS, Weng TI, Chiu CY, Lan KC, Liu SH. A ubiquitous endocrine disruptor tributyltin induces muscle wasting and retards muscle regeneration. J Cachexia Sarcopenia Muscle 2023; 14:167-181. [PMID: 36382567 PMCID: PMC9891973 DOI: 10.1002/jcsm.13119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 09/14/2022] [Accepted: 10/10/2022] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Organotin pollutant tributyltin (TBT) is an environmental endocrine disrupting chemical and is a known obesogen and diabetogen. TBT can be detected in human following consumption of contaminated seafood or water. The decrease in muscle strength and quality has been shown to be associated with type 2 diabetes in older adults. However, the adverse effects of TBT on the muscle mass and function still remain unclear. Here, we investigated the effects and molecule mechanisms of low-dose TBT on skeletal muscle regeneration and atrophy/wasting using the cultured skeletal muscle cell and adult mouse models. METHODS The mouse myoblasts (C2C12) and differentiated myotubes were used to assess the in vitro effects of low-dose tributyltin (0.01-0.5 μM). The in vivo effects of TBT at the doses of 5 and 25 μg/kg/day (n = 6/group), which were five times lower than the established no observed adverse effect level (NOAEL) and equal to NOAEL, respectively, by oral administration for 4 weeks on muscle wasting and muscle regeneration were evaluated in a mouse model with or without glycerol-induced muscle injury/regeneration. RESULTS TBT reduced myogenic differentiation in myoblasts (myotube with 6-10 nuclei: 53.9 and 35.8% control for 0.05 and 0.1 μM, respectively, n = 4, P < 0.05). TBT also decreased myotube diameter, upregulated protein expression levels of muscle-specific ubiquitin ligases (Atrogin-1 and MuRF1), myostatin, phosphorylated AMPKα, and phosphorylated NFκB-p65, and downregulated protein expression levels of phosphorylated AKT and phosphorylated FoxO1 in myotubes (0.2 and 0.5 μM, n = 6, P < 0.05). Exposure of TBT in mice elevated body weight, decreased muscle mass, and induced muscular dysfunction (5 and 25 μg/kg, P > 0.05 and P < 0.05, respectively, n = 6). TBT inhibited soleus muscle regeneration in mice with glycerol-induced muscle injury (5 and 25 μg/kg, P > 0.05 and P < 0.05, respectively, n = 6). TBT upregulated protein expression levels of Atrogin-1, MuRF1, myostatin, and phosphorylated AMPKα and downregulated protein expression level of phosphorylated FoxO1 in the mouse soleus muscles (5 and 25 μg/kg, P > 0.05 and P < 0.05, respectively, n = 6). CONCLUSIONS This study demonstrates for the first time that low-dose TBT significantly inhibits myogenic differentiation and triggers myotube atrophy in a cell model and significantly decreases muscle regeneration and muscle mass and function in a mouse model. These findings suggest that low-dose TBT exposure may be an environmental risk factor for muscle regeneration inhibition, atrophy/wasting, and disease-related myopathy.
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Affiliation(s)
- Hsien-Chun Chiu
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Rong-Sen Yang
- Departments of Orthopaedics, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Te-I Weng
- Department of Forensic Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chen-Yuan Chiu
- Center of Consultation, Center for Drug Evaluation, Taipei, Taiwan
| | - Kuo-Cheng Lan
- Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Shing-Hwa Liu
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan.,Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan.,Department of Pediatrics, College of Medicine, National Taiwan University, Taipei, Taiwan
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Pereira CLV, Ximenes CF, Merlo E, Sciortino AS, Monteiro JS, Moreira A, Jacobsen BB, Graceli JB, Ginsburg KS, Ribeiro Junior RF, Bers DM, Stefanon I. Cardiotoxicity of environmental contaminant tributyltin involves myocyte oxidative stress and abnormal Ca 2+ handling. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 247:371-382. [PMID: 30690233 PMCID: PMC7724993 DOI: 10.1016/j.envpol.2019.01.053] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 12/23/2018] [Accepted: 01/14/2019] [Indexed: 05/11/2023]
Abstract
Tributyltin (TBT) is an organotin environmental pollutant widely used as an agricultural and wood biocide and in antifouling paints. Countries began restricting TBT use in the 2000s, but their use continues in some agroindustrial processes. We studied the acute effect of TBT on cardiac function by analyzing myocardial contractility and Ca2+ handling. Cardiac contractility was evaluated in isolated papillary muscle and whole heart upon TBT exposure. Isolated ventricular myocytes were used to measure calcium (Ca2+) transients, sarcoplasmic reticulum (SR) Ca2+ content and SR Ca2+ leak (as Ca2+ sparks). Reactive oxygen species (ROS), as superoxide anion (O2•-) was detected at intracellular and mitochondrial myocardium. TBT depressed cardiac contractility and relaxation in papillary muscle and intact whole heart. TBT increased cytosolic, mitochondrial ROS production and decreased mitochondrial membrane potential. In isolated cardiomyocytes TBT decreased both Ca2+ transients and SR Ca2+ content and increased diastolic SR Ca2+ leak. Decay of twitch and caffeine-induced Ca2+ transients were slowed by the presence of TBT. Dantrolene prevented and Tiron limited the reduction in SR Ca2+ content and transients. The environmental contaminant TBT causes cardiotoxicity within minutes, and may be considered hazardous to the mammalian heart. TBT acutely induced a negative inotropic effect in isolated papillary muscle and whole heart, increased arrhythmogenic SR Ca2+ leak leading to reduced SR Ca2+ content and reduced Ca2+ transients. TBT-induced myocardial ROS production, may destabilize the SR Ca2+ release channel RyR2 and reduce SR Ca2+ pump activity as key factors in the TBT-induced negative inotropic and lusitropic effects.
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Affiliation(s)
- C L V Pereira
- Department of Physiology, Federal University of Espírito Santo- UFES, Espírito Santo, Brazil
| | - C F Ximenes
- Department of Physiology, Federal University of Espírito Santo- UFES, Espírito Santo, Brazil
| | - E Merlo
- Department of Physiology, Federal University of Espírito Santo- UFES, Espírito Santo, Brazil
| | - A S Sciortino
- Department of Physiology, Federal University of Espírito Santo- UFES, Espírito Santo, Brazil
| | - J S Monteiro
- Department of Physiology, Federal University of Espírito Santo- UFES, Espírito Santo, Brazil
| | - A Moreira
- Department of Physiology, Federal University of Espírito Santo- UFES, Espírito Santo, Brazil
| | - B B Jacobsen
- Department of Physiology, Federal University of Espírito Santo- UFES, Espírito Santo, Brazil; Department of Pharmacology, University of California, Davis, USA
| | - J B Graceli
- Department of Morphology, Federal University of Espírito Santo-UFES, Espírito Santo, Brazil
| | - K S Ginsburg
- Department of Pharmacology, University of California, Davis, USA
| | - R F Ribeiro Junior
- Department of Physiology, Federal University of Espírito Santo- UFES, Espírito Santo, Brazil; Department of Pharmacology, University of California, Davis, USA
| | - D M Bers
- Department of Pharmacology, University of California, Davis, USA
| | - I Stefanon
- Department of Physiology, Federal University of Espírito Santo- UFES, Espírito Santo, Brazil; Department of Pharmacology, University of California, Davis, USA.
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Rodrigues SML, Ximenes CF, de Batista PR, Simões FV, Coser PHP, Sena GC, Podratz PL, de Souza LN, Vassallo DV, Graceli JB, Stefanon I. Tributyltin contributes in reducing the vascular reactivity to phenylephrine in isolated aortic rings from female rats. Toxicol Lett 2014; 225:378-85. [DOI: 10.1016/j.toxlet.2014.01.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 01/01/2014] [Accepted: 01/02/2014] [Indexed: 11/26/2022]
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4
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Nath M. Toxicity and the cardiovascular activity of organotin compounds: a review. Appl Organomet Chem 2008. [DOI: 10.1002/aoc.1436] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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5
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Toovey S. Effects of weight, age, and time on artemether–lumefantrine associated ototoxicity and evidence of irreversibility. Travel Med Infect Dis 2006; 4:71-6. [PMID: 16887727 DOI: 10.1016/j.tmaid.2005.02.003] [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] [Received: 10/12/2004] [Revised: 02/24/2005] [Accepted: 02/28/2005] [Indexed: 10/25/2022]
Abstract
An association between artemether-lumefantrine treatment of uncomplicated falciparum malaria and decreases in audiometrically determined hearing thresholds has been reported. Questions arising from this report were whether the effect described is attributable to drug or disease, the effects of subject weight and age on audiometric changes, and whether the changes are reversible. Spearman's correlation coefficients were calculated to look for relationships between audiometric changes and: (1) the interval spanning artemether-lumefantrine exposure and study exit audiogram; (2) subject age; (3) subject weight. The study utilised prospectively collected data from an occupational health clinic in Mozambique (N = 150). The exposure-exit audiogram interval ranged from 3 to 392 days (mean 163.8 days, SD 91.91 days). Spearman's correlation coefficients were effectively zero for analyses (1) and (2), and too weak to contribute significantly to variances for analysis (3). Previous audiometric studies in malaria patients and healthy volunteers point away from malaria as causing irreversible audiometric changes. The audiometric changes associated with the artemether-lumefantrine treatment of malaria appear irreversible. Ototoxicity is common to many antimalarials and the elucidation of a common antiparasitic and ototoxic pathway will assist in the design of safer new antimalarials.
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Opinion of the Scientific Panel on contaminants in the food chain [CONTAM] to assess the health risks to consumers associated with exposure to organotins in foodstuffs. EFSA J 2004. [DOI: 10.2903/j.efsa.2004.102] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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Lu YC, Kuo SY, Jiann BP, Chang HT, Chen WC, Huang JK, Jan CR. Triethyltin increases cytosolic Ca(2+) levels in human osteoblasts. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2003; 14:1-7. [PMID: 21782656 DOI: 10.1016/s1382-6689(03)00004-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2002] [Accepted: 12/18/2002] [Indexed: 05/31/2023]
Abstract
In human osteosarcoma MG63 cells, effect of triethyltin, an environmental toxicant, on intracellular Ca(2+) concentration ([Ca(2+)](i)) was measured by using fura-2. Triethyltin (1-50 μM) caused a rapid and sustained plateau rise of [Ca(2+)](i) in a concentration-dependent manner (EC(50)=10 μM). Triethyltin-induced [Ca(2+)](i) rise was prevented by 50% by removal of extracellular Ca(2+) but was not altered by voltage-gated Ca(2+) channel blockers. In Ca(2+)-free medium, thapsigargin, an inhibitor of the endoplasmic reticulum (ER) Ca(2+)-ATPase, caused a monophasic [Ca(2+)](i) rise, after which the increasing effect of triethyltin on [Ca(2+)](i) was attenuated by 60%; also, pretreatment with triethyltin abolished thapsigargin-induced [Ca(2+)](i) increase. Depletion of mitochondrial Ca(2+) with carbonylcyanide m-chlorophenylhydrazone (CCCP; 2 μM) did not affect triethyltin-induced Ca(2+) release. U73122, an inhibitor of phoispholipase C, abolished ATP (but not triethyltin)-induced [Ca(2+)](i) rise. A low concentration (1 μM) of triethyltin failed to alter ATP and bradykinin-induced [Ca(2+)](i) rises. These findings suggest that triethyltin rapidly increases [Ca(2+)](i) in osteoblasts by stimulating both extracellular Ca(2+) influx and intracellular Ca(2+) release via as yet unidentified mechanism(s).
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Affiliation(s)
- Yih-Chau Lu
- Department of Orthopaedic Surgery, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan, ROC
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Jiann BP, Chou KJ, Chang HT, Chen WC, Huang JK, Jan CR. Effect of triethyltin on Ca2+ movement in Madin-Darby canine kidney cells. Hum Exp Toxicol 2002; 21:457-62. [PMID: 12412640 DOI: 10.1191/0960327102ht276oa] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The effects of the environmental toxicant, triethyltin, on Ca2+ mobilization in Madin-Darby canine kidney (MDCK) cells have been examined. Triethyltin induced an increase in cytosolic free Ca2+ levels ([Ca2+]i) at concentrations larger than 2 microM in a concentration-dependent manner. Within 5 min, the [Ca2+]i signal was composed of a gradual rise and a sustained phase. The [Ca2+]i signal was partly reduced by removing extracellular Ca2+. In Ca(2+)-free medium, pretreatment with thapsigargin (1 microM), an endoplasmic reticulum Ca2+ pump inhibitor, reduced 50 microM triethyltin-induced [Ca2+]i increase by 80%. Conversely, pretreatment with triethyltin abolished thapsigargin-induced Ca2+ release. Pretreatment with U73122 (2 microM) to inhibit phospholipase C-coupled inositol 1,4,5-trisphosphate formations failed to alter 50 microM triethyltin-induced Ca2+ release. Incubation with triethyltin at a concentration (1 microM) that did not increase basal [Ca2+]i for 3 min did not alter ATP (10 microM)- and bradykinin (1 microM)-induced [Ca2+]i increases. Collectively, this study shows that triethyltin altered Ca2+ movement in renal tubular cells by releasing Ca2+ from multiple stores in an inositol 1,4,5-trisphosphate-independent manner, and by inducing Ca2+ influx.
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Affiliation(s)
- B P Jiann
- Department of Surgery, Kaohsiung Veterans General Hospital, Taiwan, ROC
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Kanemoto Y, Ishibashi H, Matsuo S, Oyama Y, Akaike N. Modification of NMDA responses by tri-n-butyltin in rat brain neurons. Br J Pharmacol 2002; 136:201-6. [PMID: 12010768 PMCID: PMC1573346 DOI: 10.1038/sj.bjp.0704707] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
1. The effects of the organotin, tri-n-butyltin (TBT), on N-methyl-D-aspartate (NMDA) induced membrane currents were investigated in order to evaluate possible neuronal actions of this toxic environmental pollutant. Experiments were conducted on neurons acutely dissociated from the rat dorsal motor nucleus of vagus (DMV) using the nystatin-perforated patch clamp recording technique. 2. In Mg(2+)-free physiological recording solutions, the application of NMDA to single DMV neurons held at a holding potential (V(H)) of -40 mV evoked an inward current which rapidly reached a peak before declining to a steady-state inward current. This was followed, immediately after NMDA washout, by a transient outward current. TBT (100 nM) reversibly caused a slight reduction in the inward currents and greatly increased the amplitude of the outward currents. 3. The reversal potential of the NMDA-induced outward current in the presence of TBT was -86.7 mV, close to the theoretical K(+) equilibrium potential of -85.7 mV. 4. The NMDA-induced outward current was completely blocked when the K(+) in the internal solution was replaced with equimolar Cs(+). Under these conditions, the NMDA induced current was more sustained and was unaffected by TBT. 5. The NMDA-induced outward current was markedly inhibited by 5 mM tetraethylammonium chloride and 300 nM charybdotoxin, and it was abolished by removal of extracellular Ca(2+), suggesting that the outward current was due to the activation of Ca(2+)-activated K(+) channels by Ca(2+) influx through NMDA receptors. 6. In conclusion, in rat DMV neurons, TBT potentiates the Ca(2+)-activated K(+) current induced by NMDA application without having any direct effects on the NMDA-induced inward current. Given the significant role of NMDA receptor mediated excitation in various physiological and pathological processes, the modulation of this response by TBT may have an important influence on neuronal function.
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Affiliation(s)
- Yumiko Kanemoto
- Cellular and System Physiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Hitoshi Ishibashi
- Cellular and System Physiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Shinichiro Matsuo
- Cellular and System Physiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Yasuo Oyama
- Laboratory of Cellular Signaling, Faculty of Integrated Arts and Sciences, The University of Tokushima, Tokushima 770-8502, Japan
| | - Norio Akaike
- Cellular and System Physiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
- Author for correspondence:
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Kawanishi T, Kiuchi T, Asoh H, Shibayama R, Kawai H, Ohata H, Momose K, Hayakawa T. Effect of tributyltin chloride on the release of calcium ion from intracellular calcium stores in rat hepatocytes. Biochem Pharmacol 2001; 62:863-72. [PMID: 11543721 DOI: 10.1016/s0006-2952(01)00740-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The effects of tri-n-butyltin chloride (TBT), an environmental pollutant, on the release of Ca(2+) from intracellular stores were investigated in isolated rat hepatocytes. Isolated hepatocytes permeabilized with digitonin were suspended in solution, and the concentration of extracellular Ca(2+) was measured, using a fluorescent Ca(2+) dye, fura-2. In the solution containing permeabilized hepatocytes that had been preincubated with 4.0 microM TBT for 30 min, the extracellular Ca(2+) concentration was high, but the inositol 1,4,5-trisphosphate (InsP(3))-induced increase in Ca(2+) concentration was suppressed, suggesting that the extracellular release of Ca(2+) in response to TBT treatment was from intracellular stores. Images of the Ca(2+) concentration in the intracellular stores of primary cultured hepatocytes loaded with fura-2 were obtained after digitonin-permeabilization, using digitalized fluorescence microscopy. The permeabilized hepatocytes that had been preincubated with 4.0 microM TBT for 30 min had a very low fura-2 fluorescence ratio (340/380 nm), suggesting that stored Ca(2+) was released. When the hepatocytes were treated with 4.0 microM TBT after digitonin-permeabilization, the decrease in the fura-2 fluorescence ratio was very small. However, when the permeabilized hepatocytes were incubated with 4.0 microM TBT and 2.0 microM NADPH, the decrease was enhanced, raising the possibility that TBT might be metabolized to the active form(s), thus releasing Ca(2+) from intracellular stores. When the hepatocytes were preincubated with 0.1 microM TBT for 30 min and then were permeabilized, the fura-2 fluorescence ratio was almost the same as that in the control permeabilized hepatocytes. However, the InsP(3)-induced decrease in the fluorescence ratio was suppressed significantly in the permeabilized hepatocytes. These results suggest that TBT released Ca(2+) from the intracellular stores at high concentrations, and suppressed the InsP(3)-induced Ca(2+) release at non-toxic low concentrations. It is probable that the latter effect was responsible for the previously reported suppression of Ca(2+) response induced by hormonal stimulations (Kawanish et al., Toxicol Appl Pharmacol 1999;155:54-61).
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Affiliation(s)
- T Kawanishi
- Division of Biological Chemistry & Biologicals, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, 158-8501, Tokyo, Japan.
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Gassó S, Sanfeliu C, Suñol C, Rodríguez-Farré E, Cristòfol RM. Trimethyltin and triethyltin differentially induce spontaneous noradrenaline release from rat hippocampal slices. Toxicol Appl Pharmacol 2000; 162:189-96. [PMID: 10652247 DOI: 10.1006/taap.1999.8845] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The environmental contaminants trimethyltin (TMT) and triethyltin (TET) stimulated the spontaneous release of [(3)H]noradrenaline ([(3)H]NA) from hippocampal slices in a time- and concentration-dependent manner. TMT was the most potent compound, exhibiting an EC50 value 10-fold lower (3.8 microM) than that of TET (39.5 microM). Metal-evoked [(3)H]NA release did not increase in the absence of desipramine and was completely blocked by reserpine preincubation, indicating a vesicular origin of [(3)H]NA release but not a mechanism involving reversal of the transmitter transporter. The voltage-gated Na(+) channel blocker tetrodotoxin (TTX) did not affect metal-evoked [(3)H]NA release. [(3)H]NA release elicited by TMT was partially extracellular Ca(2+)-dependent, since it was significantly decreased in a Ca(2+)-free EGTA-containing medium, whereas TET induced an extracellular Ca(2+)-independent release of [(3)H]NA. Neither inhibitors of Ca(2+)-entry through Na(+)/Ca(2+)exchanger and voltage-gated calcium channels, nor agents that interfere with Ca(2+)-mobilization from intracellular stores affected [(3)H]NA release induced by TMT. TET-evoked [(3)H]NA release was reduced by ruthenium red, which depletes mitochondrial Ca(2+)stores, but was not modified by caffeine and thapsigargin, which interfere with Ca(2+)mobilization from endoplasmic reticulum. The fact that TET effect was also attenuated by DIDS, an inhibitor of anion exchange, indicates that the effect of TET on spontaneous [(3)H]NA release may be mediated by intracellular mobilization of Ca(2+) from mitochondrial stores through a Cl(-) dependent mechanism.
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Affiliation(s)
- S Gassó
- Department of Pharmacology and Toxicology, Institut d'Investigacions Biomèdiques de Barcelona, CSIC, IDIBAPS, Spain
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12
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Rao MR, Kanji VK, Sekhar V. Pesticide induced changes of nitric oxide synthase in rat brain in vitro. Drug Chem Toxicol 1999; 22:411-20. [PMID: 10234476 DOI: 10.3109/01480549909017844] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Organic insecticides are well known neurotoxicants. Nitric oxide (NO) is a neurotransmitter formed stoicheometrically with citrulline from L-arqinine through mediation of the enzyme nitric oxide synthase (NOS). We measured NOS activity in rat brain in vitro in the presence of selected organic insecticides such as, 10-200 microM conc carbaryl, kepone and malathion. All these three compounds inhibited NOS activity of rat brain in vitro in a concentration dependent manner. In most cases the changes observed were statistically significant. The order of potency, based on IC50 values of these insecticides, to inhibit NOS activity of rat brain, is carbaryl (105 microM) > Kepone (144 microM) > malathion (170 microM). We further demonstrated that these insecticides inhibit calmodulin (CaM)-stimulated NOS activity without affecting the basal enzyme activity. It is reported that the observed inhibition of NOS by selected insecticides may be due to interaction of these insecticides with Ca2+/CaM on which the NOS activity is well known to be dependent. This ultimately may lead to neurotoxicity of rat brain.
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Affiliation(s)
- M R Rao
- Department of Zoology, Sri Venkateswara University, Tirupati, India
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Kawanishi T, Asoh H, Kato T, Uneyama C, Toyoda K, Teshima R, Ikebuchi H, Ohata H, Momose K, Hayakawa T, Takahashi M. Suppression of calcium oscillation by tri-n-butyltin chloride in cultured rat hepatocytes. Toxicol Appl Pharmacol 1999; 155:54-61. [PMID: 10036218 DOI: 10.1006/taap.1998.8600] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effects of tri-n-butyltin chloride (TBT), an environmental pollutant, on cytoplasmic free calcium ion concentration ([Ca2+]i) were investigated in primary cultured rat hepatocytes. A high concentration (4.0 microM) of TBT increased resting levels of [Ca2+]i and then induced cell blebs resulting in cell death within 2 h. The increase in [Ca2+]i, but not the cell death, depended on the presence of extracellular Ca2+, suggesting that the increase in [Ca2+]i is not critical for the cytotoxicity of TBT. A low concentration (0.1 microM) of TBT did not have any toxic effect (decrease in ATP content, decrease in viability, and shape change) on cultured hepatocytes and did not change [Ca2+]i. However, the calcium responses induced by phenylephrine, [Arg8]-vasopressin, and ATP were suppressed in the cells pretreated with 0.1 microM TBT for 30 min. The suppression was not observed in the cells pretreated with 0.1 microM TBT for only 1 min. Pretreatment with 0.1 microM TBT for 30 min had no effect on the inositol 1,4,5-triphosphate content or its increase in response to hormonal stimulation. These results suggest that TBT suppresses hormone-induced calcium responses at nontoxic low concentrations.
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Affiliation(s)
- T Kawanishi
- Division of Biological Chemistry and Biologicals, National Institute of Health Sciences, Tokyo, 158-8501, USA
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Geloso MC, Vinesi P, Michetti F. Neuronal subpopulations of developing rat hippocampus containing different calcium-binding proteins behave distinctively in trimethyltin-induced neurodegeneration. Exp Neurol 1998; 154:645-53. [PMID: 9878199 DOI: 10.1006/exnr.1998.6949] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present study investigates, by immunocytochemistry, the behavior of different neuronal subpopulations of the developing rat hippocampus, selectively labeled by the calcium-binding proteins calbindin D28-k (CB), parvalbumin (PV), and calretinin (CR), in neurodegenerative processes induced by the neurotoxicant trimethyltin (TMT). Previous studies on adult rats indicated that CB-immunoreactive (IR) neurons were affected by TMT, while PV- and CR-IR neurons were selectively spared. The present findings show that only CR-IR neurons are spared in developing rats, and in addition the number of CR-IR neurons are significantly higher in the DG of treated animals. On the contrary, PV-IR neurons, spared in adult rats, were affected by TMT during development. CB-IR neurons were affected also in developing rats, as in adults. The different postnatal time-courses of calcium-binding protein expression in relationship to the time of TMT administration (presence of CR but absence of PV) could have a role in the different behavior of CR- and PV-IR cells in developing rats.
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Affiliation(s)
- M C Geloso
- Institute of Histology, Catholic University, Rome, 00168, Italy
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Kang JJ, Liu SH, Chen IL, Cheng YW, Lin-Shiau SY. Comparative studies on the induction of muscle contracture in mouse diaphragm and Ca2+ release from sarcoplasmic reticulum vesicles by organotin compounds. PHARMACOLOGY & TOXICOLOGY 1998; 82:23-7. [PMID: 9527642 DOI: 10.1111/j.1600-0773.1998.tb01393.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Effects of organotins, including triethyltin and tributyltin, on skeletal muscle were studied with diaphragm and isolated sarcoplasmic reticulum membrane vesicles. Triethyltin induced muscle contracture in mouse diaphragm while tributyltin had comparatively less potency and efficacy in inducing the muscle contracture. The contracture induced by tributyltin was inhibited when the diaphragm was pretreated with low Ca2+ medium or caffeine while the contracture induced by triethyltin persisted in the Ca2+-free medium but was inhibited by pretreatment of caffeine. Pretreatment of dithiothreitol blocked the contracture induced by tributyltin but not that by triethyltin. Triethyltin dose-dependently induced Ca2+ release from sarcoplasmic reticulum vesicles and inhibited the Ca2+-ATPase activity. These results suggested that triethyltin induced contracture in mouse diaphragm was mainly by induction of Ca2+ release and inhibition of Ca2+ uptake of the internal Ca2+ storage site the sarcoplasmic reticulum, while the tributyltin induced contracture might be due to enhancement of extracellular Ca2+ influx which further induce the release of internal Ca2+ through the Ca2+-induced Ca2+ release mechanism.
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Affiliation(s)
- J J Kang
- Institute of Toxicology, College of Medicine, National Taiwan University, Section 1, Taipei
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Geloso MC, Vinesi P, Michetti F. Calretinin-containing neurons in trimethyltin-induced neurodegeneration in the rat hippocampus: an immunocytochemical study. Exp Neurol 1997; 146:67-73. [PMID: 9225739 DOI: 10.1006/exnr.1997.6491] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The present study uses immunocytochemistry to investigate the behavior of the calretinin (CR)-containing neuronal subpopulation (interneurons) of the rat hippocampus in neurodegenerative processes induced by the neurotoxicant trimethyltin. Cell counts of CR-immunolabeled interneurons indicated that these cells are spared by the neurotoxicant-induced degeneration, characterized by a generalized neuronal loss, as shown by quantitative analysis after cresyl violet staining.
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Affiliation(s)
- M C Geloso
- Institute of Histology, Catholic University, Rome, Italy
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Hara K, Yoshizuka M, Doi Y, Fujimoto S. Effect of bis (tributyl tin) oxide on permeability of the blood-brain barrier: a transient increase. Occup Environ Med 1994; 51:735-8. [PMID: 7849849 PMCID: PMC1128096 DOI: 10.1136/oem.51.11.735] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVES To study the effect of bis (tributyl tin) oxide (TBTO) on permeability of the blood-brain barrier. METHODS Electron microscopy and an x ray microanalyser with lanthanum chloride as a tracer were used, and blood tin concentrations were determined with an atomic absorption spectrophotometer. Adult male wistar rats received 0.05 ml/kg body weight of TBTO orally. RESULTS A transient increase in paracellular permeability at the blood-brain barrier was found 2 h after the dose of TBTO. Electron dense lanthanum deposits penetrated tight junctions of the endothelia and permeated the subendothelial space. The x ray microprobe data showed an accumulation of TBTO at the tight junctions at 2 h. Leakage of tracer did not occur at 4 h, but oedematous changes in the surrounding glial cells were prominent between 4 and 8 h and had almost returned to normal by 24 h. By atomic absorption analysis, it was seen that blood tin concentrations rapidly increased at 1 h and rose to a maximum peak at 8 h, then gradually decreased to reach zero at 24 h. CONCLUSIONS Accumulated TBTO at tight junctions could have caused the temporary replacement of calcium ion by tin, which induces a transient increase in paracellular permeability throughout the blood-brain barrier.
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Affiliation(s)
- K Hara
- Department of Anatomy, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan
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Oyama Y, Ueha T, Hayashi A, Chikahisa L. Effect of tri-n-butyltin on intracellular Ca2+ concentration of mouse thymocytes under Ca(2+)-free condition. Eur J Pharmacol 1994; 270:137-42. [PMID: 8039543 DOI: 10.1016/0926-6917(94)90055-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Effect of tri-n-butyltin at concentrations ranging from 100 nM to 1 microM on the intracellular Ca2+ concentration of mouse thymocytes was examined under Ca(2+)-free conditions in comparison with those of 50 nM A23187, 100 nM thapsigargin and 10 microM cyclopiazonic acid, using the fluorescent dye for intracellular Ca2+, fluo-3. Tri-n-butyltin persistently increased the intensity of fluo-3 fluorescence while A23187, thapsigargin and cyclopiazonic acid produced a transient augmentation of the fluorescence. Pretreatment with A23187 greatly decreased the fluorescence responses induced by 1 microM tri-n-butyltin. However, the effect of thapsigargin and cyclopiazonic acid on the tri-n-butyltin-induced response was much weaker than that of A23187. In the presence of tri-n-butyltin, the transient response produced by A23187 was greatly prolonged. Results may suggest that tri-n-butyltin increases the membrane Ca2+ permeability of the intracellular organelles (cellular calcium stores) and decreases the Ca2+ pump activity of thymocyte membrane, resulting in a sustained increase in the intracellular Ca2+ concentration under Ca(2+)-free concentration.
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Affiliation(s)
- Y Oyama
- Laboratory of Cell Signalling (Pharmacology), Faculty of Integrated Arts and Sciences, University of Tokushima, Japan
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Hechtenberg S, Beyersmann D. Differential control of free calcium and free zinc levels in isolated bovine liver nuclei. Biochem J 1993; 289 ( Pt 3):757-60. [PMID: 8382049 PMCID: PMC1132239 DOI: 10.1042/bj2890757] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Modulation of intracellular signal transduction by Ca2+ and possibly Zn2+ is based on an effective homoeostatic control of the corresponding free ion concentrations. We used the fluorescent indicator fura-2 to monitor concentrations of free Ca2+ and free Zn2+ in nuclei isolated from bovine liver. The nuclei showed an ATP-stimulated accumulation of intranuclear free Ca2+, which was inhibited in the presence of the Ca(2+)-pump inhibitor thapsigargin. Furthermore, uptake and intranuclear levels of free Zn2+ were measured after incubation with different extranuclear Zn2+ concentrations. There was no stimulating effect of ATP on Zn2+ uptake. Our data suggest that the levels of intranuclear free Ca2+ and free Zn2+ are controlled differentially. A distinct regulation of free ion levels in the nucleus may contribute to the specific control of nuclear events associated with gene transcription and cell differentiation.
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Affiliation(s)
- S Hechtenberg
- Universität Bremen, Fachbereich Biologie/Chemie, Germany
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Chikahisa L, Oyama Y. Tri-n-butyltin increases intracellular Ca2+ in mouse thymocytes: a flow-cytometric study using fluorescent dyes for membrane potential and intracellular Ca2+. PHARMACOLOGY & TOXICOLOGY 1992; 71:190-5. [PMID: 1438040 DOI: 10.1111/j.1600-0773.1992.tb00543.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Effects of tri-n-butyltin (TBT) on mouse thymocytes were examined using a flow-cytometer and fluorescent dyes for membrane potential and intracellular Ca2+ ([Ca2+]i). TBT at concentrations from 1 x 10(-7) M to 3 x 10(-7) M caused hyperpolarization in thymocytes during 30 min. after drug application in a time- and dose-dependent manner. Further increase in TBT concentration (to 1 x 10(-6) M) made hyperpolarization of thymocytes more profound within 5 min. after application, thereafter gradually depolarized them during the next 25 min. TBT at 3 x 10(-8) M or more (up to 1 x 10(-6) M) increased the [Ca2+]i of thymocytes. After reaching maximum [Ca2+]i at the various TBT concentrations used within 5 min. after drug application, the [Ca2+]i slightly decreased in a time-dependent manner. Effects of TBT on membrane potential and the [Ca2+]i were greatly reduced under nominal external Ca(2+)-free condition. Results suggest that TBT can promote Ca(2+)-influx to thymocytes, resulting in hyperpolarization by activation of Ca(2+)-dependent K+ current. The increase in [Ca2+]i by TBT may be related to its cytotoxic action on thymocytes.
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Affiliation(s)
- L Chikahisa
- Department of Health Science, Faculty of Integrated Arts and Sciences, University of Tokushima, Japan
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Kodavanti PRS, Pentyala SN, Yallapragada PR, Cameron JA, Desaiah D. Inhibition of rat cardiac calcium pump activity by cationic amphiphilic drugs. Drug Dev Res 1992. [DOI: 10.1002/ddr.430260104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Cameron JA, Kodavanti PR, Pentyala SN, Desaiah D. Triorganotin inhibition of rat cardiac adenosine triphosphatases and catecholamine binding. J Appl Toxicol 1991; 11:403-9. [PMID: 1662243 DOI: 10.1002/jat.2550110605] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Triorganotins have been reported to affect heme metabolism as well as the cardiovascular system. Our recent studies indicated that these organotins inhibit cardiac sarcoplasmic reticulum Ca(2+)-transport and cAMP-stimulated phosphorylation of specific proteins involved in Ca2+ transport, suggesting their interference with cardiac adrenergic function. The present study determines the effect of three organotins--tributyltin bromide (TBT), triethyltin bromide (TET) and trimethyltin chloride (TMT)--on rat cardiac ATPases and catecholamine binding, since these phenomena are involved in cardiac function. Cardiac membrane fraction was prepared from heart ventricles of male Sprague-Dawley rats. All three organotins inhibited cardiac Na+,K(+)-ATPase, [3H]ouabain binding, K(+)-activated p-nitrophenyl phosphatase (K(+)-PNPPase) and oligomycin-sensitive (OS) and oligomycin-insensitive (OI) Mg(2+)-ATPase in a concentration-dependent manner. K(+)-PNPPase was less sensitive to these triorganotins when compared to Na+K(+)-ATPase, suggesting that triorganotins affect the Na(+)-pump activity by acting on the Na(+)-dependent phosphorylation process. OS Mg(2+)-ATPase was more sensitive to these organotins when compared to OI Mg(2+)-ATPase, confirming their potent effect on the enzymes of oxidative phosphorylation. The order of potency is TBT greater than TET greater than TMT. TET and TMT, but not TBT, inhibited [3H]norepinephrine and [3H]dopamine binding to cardiac membranes in a concentration-dependent manner, the effect being more with TET. These results suggest that triorganotins inhibit sodium pump activity as well as ATP synthesis. Since Na+,K(+)-ATPase is involved in the active transport of catecholamines, triorganotins not only inhibited the catecholamine transport but also to some extent affected catecholamine binding, thus interfering with cardiac function.
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Affiliation(s)
- J A Cameron
- Department of Biology, Jackson State University, MS 39217
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