RESUMO
INTRODUCTION: Envenomations by Bothrops snakebites can induce overwhelming systemic inflammation ultimately leading to multiple organ system failure and death. Release of damage-associated molecular pattern molecules (DAMPs), in particular of mitochondrial origin, has been implicated in the pathophysiology of the deregulated innate immune response. OBJECTIVE: To test whether whole Bothrops lanceolatus venom would induce mitochondrial dysfunction and DAMPs release in human heart preparations. METHODS: Human atrial trabeculae were obtained during cannulation for cardiopulmonary bypass from patients who were undergoing routine coronary artery bypass surgery. Cardiac fibers were incubated with vehicle and whole Bothrops lanceolatus venom for 24hr before high-resolution respirometry, mitochondrial membrane permeability evaluation and quantification of mitochondrial DNA. RESULTS: Compared with vehicle, incubation of human cardiac muscle with whole Bothrops lanceolatus venom for 24hr impaired respiratory control ratio and mitochondrial membrane permeability. Levels of mitochondrial DNA increased in the medium of cardiac cell preparation incubated with venom of Bothrops lanceolatus. CONCLUSION: Our study suggests that whole venom of Bothrops lanceolatus impairs mitochondrial oxidative phosphorylation capacity and increases mitochondrial membrane permeability. Cardiac mitochondrial dysfunction associated with mitochondrial DAMPs release may alter myocardium function and engage the innate immune response, which may both participate to the cardiotoxicity occurring in patients with severe envenomation.
