Cardiorespiratory alterations in rodents experimentally envenomed with Hadruroides lunatus scorpion venom

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 Students 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.

Cardiorespiratory alterations in rodents experimentally envenomed with Hadruroides lunatus scorpion venom

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 Students 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.(AU)

A checklist of the scorpions of Ecuador (Arachnida: Scorpiones), with notes on the distribution and medical significance of some species

Ecuador harbors one of the most diverse Neotropical scorpion faunas, hereby updated to 47 species contained within eight genera and five families, which inhabits the "Costa" (n= 17), "Sierra" (n= 34), "Oriente" (n= 16) and "Insular" (n= 2) biogeographical regions, corresponding to the western coastal, Andean, Amazonian, and the Galápagos archipelago regions, respectively. The genusTityus Koch, in the family Buthidae, responsible for severe/fatal accidents elsewhere in northern South America and the Amazonia, is represented in Ecuador by 16 species, including T. asthenes, which has caused fatalities in Colombia and Panama, and now in the Ecuadorian provinces of Morona Santiago and Sucumbíos. Underestimation of the medical significance of scorpion envenoming in Ecuador arises from the fact thatCentruroides margaritatus (Gervais) (family Buthidae) andTeuthraustes atramentarius Simon (family Chactidae), whose venoms show low toxicity towards vertebrates, frequently envenom humans in the highly populated Guayas and Pichincha provinces. This work also updates the local scorpion faunal endemicity (74.5 %) and its geographical distribution, and reviews available medical/biochemical information on each species in the light of the increasing problem of scorpionism in the country. A proposal is hereby put forward to classify the Ecuadorian scorpions based on their potential medical importance.(AU)

A checklist of the scorpions of Ecuador (Arachnida: Scorpiones), with notes on the distribution and medical significance of some species

Ecuador harbors one of the most diverse Neotropical scorpion faunas, hereby updated to 47 species contained within eight genera and five families, which inhabits the Costa (n= 17), Sierra (n= 34), Oriente (n= 16) and Insular (n= 2) biogeographical regions, corresponding to the western coastal, Andean, Amazonian, and the Galápagos archipelago regions, respectively. The genusTityus Koch, in the family Buthidae, responsible for severe/fatal accidents elsewhere in northern South America and the Amazonia, is represented in Ecuador by 16 species, including T. asthenes, which has caused fatalities in Colombia and Panama, and now in the Ecuadorian provinces of Morona Santiago and Sucumbíos. Underestimation of the medical significance of scorpion envenoming in Ecuador arises from the fact thatCentruroides margaritatus (Gervais) (family Buthidae) andTeuthraustes atramentarius Simon (family Chactidae), whose venoms show low toxicity towards vertebrates, frequently envenom humans in the highly populated Guayas and Pichincha provinces. This work also updates the local scorpion faunal endemicity (74.5 %) and its geographical distribution, and reviews available medical/biochemical information on each species in the light of the increasing problem of scorpionism in the country. A proposal is hereby put forward to classify the Ecuadorian scorpions based on their potential medical importance.(AU)

A checklist of the scorpions of Ecuador (Arachnida: Scorpiones), with notes on the distribution and medical significance of some species

Ecuador harbors one of the most diverse Neotropical scorpion faunas, hereby updated to 47 species contained within eight genera and five families, which inhabits the Costa (n= 17), Sierra (n= 34), Oriente (n= 16) and Insular (n= 2) biogeographical regions, corresponding to the western coastal, Andean, Amazonian, and the Galápagos archipelago regions, respectively. The genusTityus Koch, in the family Buthidae, responsible for severe/fatal accidents elsewhere in northern South America and the Amazonia, is represented in Ecuador by 16 species, including T. asthenes, which has caused fatalities in Colombia and Panama, and now in the Ecuadorian provinces of Morona Santiago and Sucumbíos. Underestimation of the medical significance of scorpion envenoming in Ecuador arises from the fact thatCentruroides margaritatus (Gervais) (family Buthidae) andTeuthraustes atramentarius Simon (family Chactidae), whose venoms show low toxicity towards vertebrates, frequently envenom humans in the highly populated Guayas and Pichincha provinces. This work also updates the local scorpion faunal endemicity (74.5 %) and its geographical distribution, and reviews available medical/biochemical information on each species in the light of the increasing problem of scorpionism in the country. A proposal is hereby put forward to classify the Ecuadorian scorpions based on their potential medical importance.