Skip to main content
Log in

Long-term Mercury Exposure Accelerates the Development of Hypertension in Prehypertensive Spontaneously Hypertensive Rats Inducing Endothelial Dysfunction: the Role of Oxidative Stress and Cyclooxygenase-2

  • Published:
Biological Trace Element Research Aims and scope Submit manuscript

Abstract

Mercury is a metal widely dispersed in nature that when in contact with human organism, it damages the cardiovascular system. Long-term mercury exposure for 30 days induces endothelial dysfunction without blood pressure changes in normotensive adult rats. However, it is not known whether exposure to mercury can exacerbate endothelial dysfunction and hypertension development in predisposed animals. Thus, we aimed to investigate the effects of long-term mercury exposure on the blood pressure (BP) and in the isolated aortas of young normotensive and prehypertensive spontaneously hypertensive rats (SHRs). Four-week-old male Wistar rats and SHRs were treated daily with mercury chloride (HgCl2) (1st dose, 4.6 μg/kg; subsequent dose, 0.07 μg/kg/day, im, 30 days) or vehicle. BP was assessed weekly and the vascular reactivity to phenylephrine was evaluated in isolated aorta from rats exposed or not to mercury. Mercury exposure did not affect BP in young Wistar rats but accelerated the development of hypertension in young SHRs. Vascular reactivity to phenylephrine increased only in the aorta from mercury-exposed SHRs. While HgCl2 exposure in SHRs did not alter nitric oxide production, we observed increased superoxide anion production and decreased superoxide dismutase-1 protein expression, and enhanced cyclooxygenase-2 (COX-2) participation with increased prostaglandin (PGE2) production and decreased prostacyclin. In the Wistar group, mercury exposure did not alter superoxide anion production or the COX-2 pathway. Mercury exposure accelerated the natural course of hypertension in young SHRs and increased oxidative stress associated with reduced participation of antioxidant enzymes, an activated COX-2 pathway, thereby producing endothelial dysfunction, which is a risk factor in prehypertensive individuals.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7

Similar content being viewed by others

References

  1. Guzzi G, La Porta CAM (2008) Molecular mechanisms triggered by mercury. Toxicology 244:1–12. https://doi.org/10.1016/j.tox.2007.11.002

    Article  CAS  PubMed  Google Scholar 

  2. Vassallo DV, Simões MR, Furieri LB et al (2011) Toxic effects of mercury, lead and gadolinium on vascular reactivity. Brazilian J Med Biol Res 44:939–946. https://doi.org/10.1590/S0100-879X2011007500098

    Article  CAS  Google Scholar 

  3. Mortazavi SMJ, Mortazavi G, Paknahad M (2016) A review on the distribution of Hg in the environment and its human health impacts. J Hazard Mater 310:278–279. https://doi.org/10.1016/j.jhazmat.2016.02.043

    Article  CAS  PubMed  Google Scholar 

  4. Nedellec V, Rabl A (2016) Costs of health damage from atmospheric emissions of toxic metals: part 2—analysis for mercury and lead. Risk Anal 36:2096–2104. https://doi.org/10.1111/risa.12598

    Article  PubMed  Google Scholar 

  5. Salonen JT, Seppänen K, Lakka TA et al (2000) Mercury accumulation and accelerated progression of carotid atherosclerosis: a population-based prospective 4-year follow-up study in men in eastern Finland. Atherosclerosis 148:265–273. https://doi.org/10.1016/S0021-9150(99)00272-5

    Article  CAS  PubMed  Google Scholar 

  6. Wiggers GA, Furieri LB, Briones AM et al (2016) Cerebrovascular endothelial dysfunction induced by mercury exposure at low concentrations. Neurotoxicology 53:282–289. https://doi.org/10.1016/j.neuro.2016.02.010

    Article  CAS  PubMed  Google Scholar 

  7. Furieri LB, Galán M, Avendaño MS, García-Redondo AB, Aguado A, Martínez S, Cachofeiro V, Bartolomé MV, Alonso MJ, Vassallo DV, Salaices M (2011) Endothelial dysfunction of rat coronary arteries after exposure to low concentrations of mercury is dependent on reactive oxygen species. Br J Pharmacol 162:1819–1831. https://doi.org/10.1111/j.1476-5381.2011.01203.x

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  8. Wiggers GA, Stefanon I, Padilha AS et al (2008) Low nanomolar concentration of mercury chloride increases vascular reactivity to phenylephrine and local angiotensin production in rats. Comp Biochem Physiol - C Toxicol Pharmacol 147:252–260. https://doi.org/10.1016/j.cbpc.2007.10.003

    Article  CAS  PubMed  Google Scholar 

  9. Wiggers GA, Peçanha FM, Briones AM et al (2008) Low mercury concentrations cause oxidative stress and endothelial dysfunction in conductance and resistance arteries. Am J Physiol Heart Circ Physiol 295:H1033–H1043. https://doi.org/10.1152/ajpheart.00430.2008

    Article  CAS  PubMed  Google Scholar 

  10. Vassallo DV, Wiggers GA, Padilha AS, Simões MR (2019) Endothelium:a target for harmful actions of metals. Curr Hypertens Rev 15:1–8. https://doi.org/10.2174/1573402115666190115153759

    Article  Google Scholar 

  11. Rizzetti DA, Torres JGD, Escobar AG et al (2013) Apocynin prevents vascular effects caused by chronic exposure to low concentrations of mercury. PLoS One 8. https://doi.org/10.1371/journal.pone.0055806

  12. García Gómez M, Boffetta P, Caballero Klink JD et al (2007) Cardiovascular mortality in mercury miners. Med Clin (Barc) 128:766–771

    Article  Google Scholar 

  13. Kobal AB, Horvat M, Prezelj M et al (2004) The impact of long-term past exposure to elemental mercury on antioxidative capacity and lipid peroxidation in mercury miners. J Trace Elem Med Biol 17:261–274. https://doi.org/10.1016/S0946-672X(04)80028-2

    Article  CAS  PubMed  Google Scholar 

  14. Torres AD, Rai AN, Hardiek ML (2000) Mercury intoxication and arterial hypertension: report of two patients and review of the literature. Pediatrics 105:e34. https://doi.org/10.1542/peds.105.3.e34

    Article  CAS  PubMed  Google Scholar 

  15. Pecanha FM, Wiggers GA, Briones AM, Perez-Giron JV, Miguel M, Garcia-Redondo AB, Vassallo DV, Alonso MJ, Salaices M (2010) The role of cyclooxygenase (COX)-2 derived prostanoids on vasoconstrictor responses to phenylephrine is increased by exposure to low mercury concentration. J Physiol Pharmacol 61:29–36

    CAS  PubMed  Google Scholar 

  16. Clarkson TW (1993) Molecular and ionic mimicry of toxic metals. Annu Rev Phnrmacol Toxicol 32:545–571

    Article  Google Scholar 

  17. Halbach S (1990) Mercury compounds: lipophilicity and toxic effects on isolated myocardial tissue. Arch Toxicol 64:315–319

    Article  CAS  Google Scholar 

  18. Abramson JJ, Salama G (1989) Critical sulfhydryls regulate calcium release from sarcoplasmic reticulum. J Bioenerg Biomembr 21:283–294. https://doi.org/10.1007/BF00812073

    Article  CAS  PubMed  Google Scholar 

  19. Azevedo BF, Furieri LB, Peçanha FM et al (2012) Toxic effects of mercury on the cardiovascular and central nervous systems. J Biomed Biotechnol 2012:1–11. https://doi.org/10.1155/2012/949048

    Article  CAS  Google Scholar 

  20. Ward NC, Hodgson JM, Puddey IB et al (2004) Oxidative stress in human hypertension: association with antihypertensive treatment, gender, nutrition, and lifestyle. Free Radic Biol Med 36:226–232. https://doi.org/10.1016/j.freeradbiomed.2003.10.021

    Article  CAS  PubMed  Google Scholar 

  21. Lataro RM, Silva MAB, Mestriner FL et al (2019) Chronic treatment with acetylcholinesterase inhibitors attenuates vascular dysfunction in spontaneously hypertensive rats. Am J Hypertens

  22. Lee RM (1985) Vascular changes at the prehypertensive phase in the mesenteric arteries from spontaneously hypertensive rats. Blood Vessels 22:105–126

    CAS  PubMed  Google Scholar 

  23. Puzserova A, Ilovska V, Balis P et al (2014) Age-related alterations in endothelial function of femoral artery in young SHR and WKY rats. Biomed Res Int 2014. https://doi.org/10.1155/2014/658479

  24. Dickhout JG, Lee RM (1998) Blood pressure and heart rate development in young spontaneously hypertensive rats. Am J Phys 274:H794–H800. https://doi.org/10.1038/tp.2017.130

    Article  CAS  Google Scholar 

  25. Yamori Y (1994) Development of the spontaneously hypertensive rat (SHR), the stroke-prone SHR (SHRSP) and their various substrain models for hypertension-related cardiovascular disease. Elsevier 16:346–364

  26. Cooper G IV (1987) Cardiocyte adaptation to chronically altered load. Annu Rev Physiol 49:501–518

    Article  CAS  Google Scholar 

  27. Gupta M, Bansal JK, Khanna CM (1996) Blood mercury in workers exposed to the preparation of mercury cadmium telluride layers on cadmium telluride base. Ind Health 34:421–425. https://doi.org/10.2486/indhealth.34.421

    Article  CAS  PubMed  Google Scholar 

  28. Chen C, Qu L, Li B, Xing L, Jia G, Wang T, Gao Y, Zhang P, Li M, Chen W, Chai Z (2005) Increased oxidative DNA damage, as assessed byurinary 8-hydroxy-2-deoxyguanosine concentrations, and serum redoxstatus in persons exposed to mercury. Clin Chem 51:759–767

    Article  CAS  Google Scholar 

  29. United States Environmental Protection Agency (USEPA) (1998) Mercury health effects. EPA 600/8, Washington

    Google Scholar 

  30. Ibarra M, López-Guerrero JJ, Mejía-Zepeda R, Villalobos-Molina R (2006) Endothelium-dependent inhibition of the contractile response is decreased in aorta from aged and spontaneously hypertensive rats. Arch Med Res 37:334–341. https://doi.org/10.1016/j.arcmed.2005.06.015

    Article  CAS  PubMed  Google Scholar 

  31. Vassallo DV, Simões MR, Giuberti K, Azevedo BF, Ribeiro Junior RF, Salaices M, Stefanon I (2019) Effects of chronic exposure to mercury on angiotensin-converting enzyme activity and oxidative stress in normotensive and hypertensive rats. Arq Bras Cardiol 112:374–380. https://doi.org/10.5935/abc.20180271

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  32. Cacanyiova S, Berenyiova A, Kristek F, Drobna M, Ondrias K, Grman M (2016) The adaptive role of nitric oxide and hydrogen Sulphide in vasoactive responses of thoracic aorta is triggered already in young spontaneously hypertensive rats. J Physiol Pharmacol 67:501–512

    CAS  PubMed  Google Scholar 

  33. Radaelli A, Mircoli L, Mori I et al (1998) Nitric oxide-dependent vasodilation in young spontaneously hypertensive rats. Hypertension 32:735–739. https://doi.org/10.1161/01.HYP.32.4.735

    Article  CAS  PubMed  Google Scholar 

  34. Fardin PBA, Simões RP, Schereider IRG, Almenara CCP, Simões MR, Vassallo DV (2019) Chronic mercury exposure in prehypertensive SHRs accelerates hypertension development and activates vasoprotective mechanisms by increasing NO and H2O2 production. Cardiovasc Toxicol:1–14. https://doi.org/10.1007/s12012-019-09545-6

  35. Azevedo BF, Simões MR, Fiorim J et al (2016) Chronic mercury exposure at different concentrations produces opposed vascular responses in rat aorta. Clin Exp Pharmacol Physiol 43:712–719. https://doi.org/10.1111/1440-1681.12578

    Article  CAS  PubMed  Google Scholar 

  36. Ito H, Torii M, Suzuki T (1995) Decreased superoxide dismutase activity and increased superoxide anion production in cardiac hypertrophy of spontaneously hypertensive rats. Clin Exp Hypertens 17:803–816. https://doi.org/10.3109/10641969509033636

    Article  CAS  PubMed  Google Scholar 

  37. Briones AM, Touyz RM (2010) Oxidative stress and hypertension: current concepts. Curr Hypertens Rep 12:135–142. https://doi.org/10.1007/s11906-010-0100-z

    Article  CAS  PubMed  Google Scholar 

  38. Drummond G, Selemidis S, Griendling K, Sobey C (2011) Combating oxidative stress in vascular disease: NADPH oxidases as therapeutic targets. Nat Rev Drug Discov 10:453–471. https://doi.org/10.1038/nrd3403.Combating

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  39. Rizzetti DA, Torres JGD, Escobar AG, da Silva TM, Moraes PZ, Hernanz R, Peçanha FM, Castro MM, Vassallo DV, Salaices M, Alonso MJ, Wiggers GA (2017) The cessation of the long-term exposure to low doses of mercury ameliorates the increase in systolic blood pressure and vascular damage in rats. Environ Res 155:182–192. https://doi.org/10.1016/j.envres.2017.02.022

    Article  CAS  PubMed  Google Scholar 

  40. Kumar KV, Das UN (1993) Are free radicals involved in the pathobiology of human essential hypertension? Free Radic Res Commun 19:59–66

    Article  CAS  Google Scholar 

  41. Pedro-Botet J, Covas MI, Martín S, Rubiés-Prat J (2000) Decreased endogenous antioxidant enzymatic status in essential hypertension. J Hum Hypertens 14:343–345. https://doi.org/10.1038/sj.jhh.1001034

    Article  CAS  PubMed  Google Scholar 

  42. Pawluk H, Pawluk R, Robaczewska J, Kędziora-Kornatowska K, Kędziora J (2017) Biomarkers of antioxidant status and lipid peroxidation in elderly patients with hypertension. Redox Rep 22:542–546. https://doi.org/10.1080/13510002.2017.1372072

    Article  CAS  PubMed  Google Scholar 

  43. Wang M, Ihida-Stansbury K, Kothapalli D et al (2011) Microsomal prostaglandin E2 synthase-1 modulates the response to vascular injury. Circulation 123:631–639. https://doi.org/10.1161/CIRCULATIONAHA.110.973685

    Article  CAS  PubMed  Google Scholar 

  44. Camacho M, Dilmé J, Solà-Villà D, Rodríguez C, Bellmunt S, Siguero L, Alcolea S, Romero JM, Escudero JR, Martínez-González J, Vila L (2013) Microvascular COX-2/mPGES-1/EP-4 axis in human abdominal aortic aneurysm. J Lipid Res 54:3506–3515. https://doi.org/10.1194/jlr.m042481

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  45. Wang M, Lee E, Song W, Ricciotti E, Rader DJ, Lawson JA, Puré E, FitzGerald G (2008) Microsomal prostaglandin E synthase-1 deletion suppresses oxidative stress and angiotensin II-induced abdominal aortic aneurysm formation. Circulation 117:1302–1309. https://doi.org/10.1161/CIRCULATIONAHA.107.731398

    Article  CAS  PubMed  Google Scholar 

  46. Avendaño MS, Martínez-Revelles S, Aguado A et al (2016) Role of COX-2-derived PGE2on vascular stiffness and function in hypertension. Br J Pharmacol 173:1541–1555. https://doi.org/10.1111/bph.13457

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  47. Martínez-Revelles S, Avendaño MS, García-Redondo AB et al (2013) Reciprocal relationship between reactive oxygen species and cyclooxygenase-2 and vascular dysfunction in hypertension. Antioxid Redox Signal 18:51–65. https://doi.org/10.1089/ars.2011.4335

    Article  CAS  PubMed  Google Scholar 

  48. da Cunha V, Souza HP, Rossoni LV, França AS, Vassallo DV (2000) Effects of mercury on the isolated perfused rat tail vascular bed are endothelium-dependent. Arch Environ Contam Toxicol 39:124–130

    Article  Google Scholar 

  49. Xavier FE, Rossoni LV, Alonso MJ, Balfagón G, Vassallo DV, Salaices M (2004) Ouabain-induced hypertension alters the participation of endothelial factors in α-adrenergic responses differently in rat resistance and conductance mesenteric arteries. Br J Pharmacol 143:215–225. https://doi.org/10.1038/sj.bjp.0705919

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  50. Liu D, Liu B, Luo W et al (2015) A vasoconstrictor response to COX-1-mediated prostacyclin synthesis in young rat renal arteries that increases in pre-hypertensive conditions. Am J Physiol Heart Circ Physiol 309:804–811. https://doi.org/10.1152/ajpheart.00150.2015

    Article  CAS  Google Scholar 

Download references

Funding

This work was supported by grants from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES—Finance code 001); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and Fundação de Amparo à Pesquisa do Espírito Santo (FAPES—Grant 80600115, 73370215, 80598773). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Alessandra Simão Padilha.

Ethics declarations

Conflict of Interest

The authors declare that they have no conflicts of interest.

Ethical Approval

All procedures performed in studies involving animals were in accordance with the ethical standards of the institution or practice at which the studies were conducted (Ethics Committee of the Federal University of Espirito Santo 09/2018).

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Simões, R.P., Fardin, P.B.A., Simões, M.R. et al. Long-term Mercury Exposure Accelerates the Development of Hypertension in Prehypertensive Spontaneously Hypertensive Rats Inducing Endothelial Dysfunction: the Role of Oxidative Stress and Cyclooxygenase-2. Biol Trace Elem Res 196, 565–578 (2020). https://doi.org/10.1007/s12011-019-01952-8

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s12011-019-01952-8

Keywords

Navigation