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 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.

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.

Retrospective study of pre-anesthetic electrocardiogram examination of 700 dogs conducted at the veterinary hospital of UFMG (2013-2014) / Estudo retrospectivo de exames eletrocardiográficos pré-anestésicos em 700 cães realizados no hospital veterinário da UFMG (2013-2014)

Pre-operative electrocardiograms performed in 700 dogs were analyzed in order to establish correlation between sex, age, indication for surgery, body condition score, breed and weight. Initially a clinical questionnaire was filled out from each owner, including age, breed, sex, weight, clinical history and surgical indication. Dogs above 6 years of age or those showing any kind of cardiac auscultation disturbances were referred to electrocardiogram (ECG) evaluation. All ECG were performed and analyzed by the same veterinary specialist. Abnormalities at ECG were founnd in 364 of 700 (52%) evaluated dogs, and the most frequent variation was sinus arrhythmia, observed in 293 dogs (25.4%). No significant correlation was found between the electrocardiographic alterations with weight, sex and age of the animals. Therefore ECG should be conducted routinely regardless of age, sex, breed or surgical indication, highlighting its value for determining a safe anesthetic protocol that promotes minimal cardiopulmonary depression and allows rapid post-surgical recovery.

Foram analisados exames eletrocardiográficos pré-operatórios de 700 cães, com o objetivo de estabelecer correlação entre sexo, idade, indicação cirúrgica, condição corporal, raça e peso. Inicialmente, um questionário clínico foi preenchido por cada proprietário, com informações sobre sexo, raça, sexo, peso, histórico clínico e indicação cirúrgica. Os cães com mais de seis anos de idade e aqueles que apresentavam qualquer tipo de alteração à auscultação cardíaca foram encaminhadas para avaliação por meio de eletrocardiograma (ECG). Todos os ECG foram realizados e analisados pelo mesmo veterinário especialista. As anormalidades ao ECG foram observadas em 364 dos 700 (52%) cães avaliados e a alteração mais frequente foi a arritmia sinusal, observada em 293 (25,4%) cães. Nenhuma correlação significante foi observada entre as alterações eletrocardiográficas com o peso, o sexo e a idade dos animais. Sugere-se, portanto que o exame de ECG seja realizado de forma rotineira, independente de idade, sexo, raça ou indicação cirúrgica, destacando seu valor para a determinação de um protocolo anestésico que promova mínima depressão cardiopulmonar e rápida recuperação pós-cirúrgica.

Avaliação das alterações cardiotóxicas decorrentes do uso da doxorrubicina: estudo experimental em ratos / Clinical evaluation of the doxorubicin-induced cardiotoxicity: experimental study in rats

A doxorrubicina é um dos quimioterápicos mais utilizados no tratamento de tumores sólidos e hematopoiéticos, embora possa causar reações adversas, especialmente cardiomiopatia secundßria. Apesar do potencial cardiotóxico, a doxorrubicina ainda é amplamente utilizada devido a sua alta eficßcia e baixo custo. esse trabalho objetiva-se estudar a sintomatologia associada ao uso da doxorrubicina em ratos, para elucidar seus efeitos cardiotóxicos. Dez ratos Wistar machos foram distribuidos em dois grupos: tratado, o qual recebeu 5mg/kg de doxorrubicina em 1,0mL de salina, via intraperitoneal a cada sete dias, durante quatro se- manas; e controle, o qual recebeu apenas 1,0 mL de salina nas mesmas condições descritas. Realizou-se eletrocardiograma antes dos tratamentos e após quatro semanas, juntamente com ecocardiograma. Os animais do grupo tratado apresentaram apatia, emagrecimento, desidratação e fezes diarreicas com muco, indicando disfunção metabólica decorrente da toxicidade do quimioterßpico. Em dois animais, o quadro clínico evoluiu para óbito, 19 dias após início do tratamento. No eletrocardiograma detectou-se aumento na amplitude das ondas P e R, sugerindo sobrecarga atrial e ventricular esquerda, respectivamente. A onda T apresentou amplitude superior à onda R, provavelmente devido a alterações eletrolíticas secundßrias ao quadro de desidratação e diarreia. Arritmias atriais e ventriculares, contudo, não foram detectadas. Foi diagnosticada disfunção ventricular nos animais que receberam doxorrubicina, quando avaliados por ecocardiografia de deformação miocßrdica (velocidade e deslocamento radiais do ventrículo esquerdo). Conclui-se que a doxorrubicina provoca cardiotoxicidade dose-dependente com redução progressiva da função ventricular esquerda, a qual pode ser diagnosticada precocemente com a ecocardiografia strain...

Doxorubicin is one of lhe most common drugs used in lhe treatment of solid and emopoietic tumors; however it causes a dose-dependet adverse effects, mainly cardiomyopathy. Despite the obvious cardiac toxicity potential, doxorubicin is still widely used due t0 its high efficiency and low cost. Therefore, this research aims to study the sytmptoms associated with the use of doxorubicin in rats, in order to elucidate its cardiac toxicity. Ten male Wistar rats were distributed into two groups: treated, which received 5mg/kg of doxorubicin in 1.0 mL saline intraperitoneal weekly, for four weeks, and control, which received only 1.0 mL of saline under lhe same conditions described. Electrocardiography was performed before treatment and atter four weeks when echocardiography was done as well. The treated group showed apathy, weight loss, dehydration and diarrheal stools with mucus, indicating metabolic dystunction due to the toxicity of chemotherapy. Two animals died, 19 days after lhe beginning of the experiment The electrocardiogram detected an increase in the amplitude of P. R and S waves, suggesting atrial and ventricular overload, respectively. The greater amplitude of the T-wave when compared to the R wave occurred probably due to electrolyte alterations caused by dehydration and diarrhea. Nevertheless, atrial and ventricular ar- rhythmias were not detected. Ventricular dysfunction was diagnosed in animais that received doxorubicin when evaluated by strain echocardiography (left ventricular radial velocity and displacement). It was concluded that doxorubicin causes a dose-dependent cardiotoxicity, with a progressive left ventricular dysfunction which may be early detected using the strain echocardiography...