An investigator is studying a drug that acts on a G protein-coupled receptor in the pituitary gland. Binding of the drug to this receptor leads to increased production of inositol triphosphate (IP3) in the basophilic cells of the anterior pituitary. Administration of this drug every 90 minutes is most likely to be beneficial in the treatment of which of the following conditions?
AProstate cancer
BVariceal bleeding
CCentral diabetes insipidus
DAnovulatory infertility
EHyperkalemia
An investigator is studying the effect of a high-lipid diet on glucose metabolism in Wistar rats. The experimental rat group is fed a high-lipid diet while the control group is fed a low-lipid diet. Two months after initiation of the experiment, the rats in both groups are injected with insulin and serum glucose measurements are obtained. Compared to the control group, the high-lipid diet group has a significantly higher average serum glucose after receiving insulin. Which of the following intracellular changes is most likely involved in the pathogenesis of this finding?
ADecreased activation of caspase 8
BDecreased production of protein kinase A
CDecreased expression of TP53
DIncreased exposure of nuclear localization signal
EIncreased activity of serine kinases
A 30-year-old woman presents to her physician for her annual checkup. She has diabetes mellitus, type 1 and takes insulin regularly. She reports no incidents of elevated or low blood sugar and that she is feeling energetic and ready to face the morning every day. Her vital signs and physical are normal. On the way home from her checkup she stops by the pharmacy and picks up her prescription of insulin. Later that night she takes a dose. What is the signaling mechanism associated with this medication?
AIncreased concentration intracellular cAMP
BIncreased permeability of the cell membrane to negatively charged molecules
CActivation of tyrosine kinase
DRapid and direct upregulation of enzyme transcription
EIncreased permeability of the cell membrane to positively charged molecules
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