A 52 year old man comes to the emergency department with jaw stiffness and painful muscle spasms 8 days after stepping on a rusty nail while working on a farm. He has not received routine medical care for many years. Examination shows risus sardonicus and generalized hyperreflexia. Which of the following is the most likely mechanism of the toxin responsible for this patient’s symptoms?
- A)Blockade of glycine and GABA release from inhibitory interneuronsGABARITO
- B)Activation of adenylate cyclase in enterocytes
- C)Inhibition of acetylcholine release at the neuromuscular junction
- D)Direct endothelial invasion causing vasculitis
- E)Inactivation of the 60S ribosomal subunit
Explicação
Blockade of glycine and GABA release from inhibitory interneurons is correct. Tetanospasmin travels retrograde to the central nervous system and cleaves synaptobrevin, preventing release of inhibitory neurotransmitters from Renshaw cells. The resulting disinhi... Ver explicação completa e trilha adaptativa →