A drug research team has synthesized a novel oral drug that acts as an agonist at multiple adrenergic receptors. When administered in animals, it has been shown to produce urinary retention at therapeutic doses with the absence of other manifestations of adrenergic stimulation. The researchers are interested in understanding signal transduction and molecular mechanisms behind the action of the novel drug. Which of the following receptors would most likely transduce signals across the plasma membrane following the administration of this novel drug?
AGoPCRs (Go protein-coupled receptors)
BGsPCRs (Gs protein-coupled receptors)
CGqPCRs (Gq protein-coupled receptors)
DGtPCRs (Gt protein-coupled receptors)
EGiPCRs (Gi protein-coupled receptors)
A 47-year-old woman presents to a local medical shelter while on a mission trip with her church to help rebuild homes after a hurricane. She has been experiencing severe nausea, vomiting, and diarrhea for the last 2 days and was feeling too fatigued to walk this morning. On presentation, her temperature is 99.2°F (37.3°C), blood pressure is 95/62 mmHg, pulse is 121/min, and respirations are 17/min. Physical exam reveals decreased skin turgor, and a stool sample reveals off-white watery stools. Gram stain reveals a gram-negative, comma-shaped organism that produces a toxin. Which of the following is consistent with the action of the toxin most likely involved in the development of this patient's symptoms?
ADecreased ribosomal activity
BIncreased membrane permeability
CCleavage of junctional proteins
DIncreased adenylyl cyclase activity
EActivation of receptor tyrosine kinase
A 25-year-old man presents to the physician with 2 days of profuse, watery diarrhea. He denies seeing blood or mucus in the stools. On further questioning, he reveals that he eats a well-balanced diet and generally prepares his meals at home. He remembers having some shellfish from a street vendor 3 days ago. He takes no medications. His past medical history is unremarkable. Which of the following mechanisms most likely accounts for this patient’s illness?
ATyrosine kinase phosphorylation
BADP-ribosylation of Gs protein
CTyrosine kinase dephosphorylation
DOsmotic effect of intestinal contents
EInflammation of the gastrointestinal wall
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