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Research article - Vol. 23, 2017 |
Cardiorespiratory alterations in rodents experimentally envenomed with Hadruroides lunatus scorpion venom
1 Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte CP: 486 CEP: 31270-901, MG, Brazil.
2 College of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
3 Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
4 Instituto Nacional de Salud, Universidad Nacional Mayor de San Marcos y Peru. Universidad Científica del Sur, Lima, Peru.
5 Universidad Científica del Sur, Lima, Peru.
ABSTRACT
Background
Hadruroides lunatus is the most abundant scorpion species in the Peruvian central coast, where most of the accidents involving humans are registered. In spite of its prevalence, there are only very few studies on H. lunatus envenomation. The aim of the present study was to analyze the cardiorespiratory alterations caused by H. lunatus envenomation in rodents.
Methods
Wistar rats injected with H. lunatus scorpion venom were submitted to electrocardiography. After euthanasia, rat lungs were collected and histopathologically analyzed. Mouse cardiomyocytes were used to perform immunofluorescence and calcium transient assays. Data were analyzed by ANOVA or Student’s t-test. The significance level was set at p< 0.05.
Results
It was observed that H. lunatus venom increased heart rate and caused arrhythmia, thereby impairing the heart functioning. Lungs of envenomed animals showed significant alterations, such as diffuse hemorrhage. In addition, immunofluorescence showed that H. lunatus venom was capable of binding to cardiomyocytes. Furthermore, mouse ventricular cardiomyocytes incubated with H. lunatus venom showed a significant decrease in calcium transient, confirming that H. lunatus venom exerts a toxic effect on heart.
Conclusion
Our results showed that H. lunatus venom is capable of inducing cardiorespiratory alterations, a typical systemic effect of scorpionism, stressing the importance of medical monitoring in envenomation cases.
Key words: Hadruroides lunatus venom; Cardiorespiratory alterations; Electrocardiography; Immunofluorescence; Calcium transient.
Funding
This work was supported by the Brazilian Coordination for the Improvement of Higher Education Personnel (CAPES – project “Toxinologia” no. 23038000825/2011-63), by Brazilian National Council for Scientific and Technological Development (CNPq – “Chamada Bilateral” no. 17/2013, process: 490269/2013-3) and by funds of the INCTTOX Program of CNPq.
Ethics approval and consent to participate
All experimental procedures performed were in accordance to the guidelines of the Institutional Committee for Animal Care and Use of UFMG, Brazil, and the Guide for the Care and Use of Laboratory Animals (NIH, 8thedition, 2011). The present study was approved by the Ethics Committee on the Use of Laboratory Animals of UFMG (092/11) (CETEA-UFMG).
Received: February 22, 2016.
Revised: July 6, 2016.
Accepted: July 15, 2016.
Correspondence: olortegi@icb.ufmg.br
Authors’ contributions
FCO and CGD contributed equally to this work. They designed and developed the experiments, analyzed the results and prepared the manuscript for publication. MSO conducted the electrocardiogram experiments, analyzed the results and helped revising the manuscript for publication, under the supervision of MMM. MSO and MMM helped with organ collection, slides preparation and statistical analysis. KLPC assisted with the preparation of samples and animals, being responsible for their maintenance during all the work. AL and ERMG worked on the isolation of the cardiomyocytes and performed confocal microscopy and calcium transient experiments, under the supervision of SG, who was responsible also for manuscript drafting. LLS helped conducting the immunofluorescence assays. CB collected, maintained the scorpions and worked in the extraction of venom by the electrical stimulation method. CCO is the corresponding author and designer of the research. All authors read and approved the final manuscript.