41 - 45 Pharmacology SBAs for the Primary FRCA

41 - 45 Pharmacology SBAs for the Primary FRCA
Photo by Nguyen Dang Hoang Nhu / Unsplash


Question 41

You are cautiously administering IV salbutamol to a patient with life-threatening asthma in the Emergency Department, when a curious bystander asks you about adenylate cyclase.

Which of the following is true?

  • Adenylate cyclase is activated directly by catecholamines
  • Adenylate cyclase is a membrane-bound protein
  • Aminophylline stimulates phosphodiesterase to break cAMP down to 5'-AMP
  • Adenylate cyclase catalyses production of ATP from cAMP
  • Salbutamol stimulates beta-2 receptors, resulting in an indirect reduction in adenylate cyclase activity

Answer

  • Adenylate cyclase is a membrane bound protein

There is also a cytosolic version, but that doesn't stop the above from being true I guess.

  • Adenylate cyclase is indirectly activated by catecholamines
  • Aminophylline inhibits phosphodiesterase
  • Adenylate cyclase catalyses production of cAMP from ATP
  • Salbutamol stimulates beta-2 receptors, resulting in an indirect increase in adenylate cyclase activity