A 27-year-old man presents to the emergency department with severe muscle cramps, abdominal rigidity, diaphoresis, and hypertension (BP 168/102 mmHg, HR 118/min) after sustaining a bite while cleaning a woodpile 4 hours ago. Temperature is 37.2°C and SpO2 is 98% on room air. Physical examination reveals no fang marks or local swelling. Serum creatinine is normal. Which of the following best describes the mechanism of the toxin involved?
- A)Inhibits aldehyde dehydrogenase
- B)Causes massive release of neurotransmitters from presynaptic terminalsGABARITO
- C)Blocks presynaptic release of acetylcholine
- D)Oxidizes hemoglobin iron to Fe3+
- E)Inhibits cytochrome oxidase
Explicação
Black widow spider venom contains alpha-latrotoxin, which causes massive release of neurotransmitters and produces painful muscle cramps, autonomic activation, and diaphoresis. The presentation contrasts with botulism, which blocks acetylcholine release. Ver explicação completa e trilha adaptativa →