An Experiment Is Conducted to Assess the Effects of Drug

question 40

Multiple Choice

An experiment is conducted to assess the effects of drug A on the hemodynamic actions of epinephrine.  Two groups of healthy volunteers are selected.  The first group receives only low-dose epinephrine, and its effects on diastolic blood pressure and heart rate are monitored and shown below (epinephrine group) .  The second group is pretreated with drug A and then infused with low-dose epinephrine to produce a new set of curves (epinephrine + drug A group) . Which of the following medications is most likely to be drug A?

• A)Atropine
• B)Isoproterenol
• C)Phentolamine
• D)Phenylephrine
• E)Propranolol

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Definitions:

mRNA Synthesis

The process of synthesizing messenger RNA (mRNA) from a DNA template during gene expression, allowing for protein production.

Structural Gene

A gene that codes for any RNA or protein product other than a regulatory factor.

Transcription Factors

Proteins that bind to specific DNA sequences, thereby controlling the transfer (transcription) of genetic information from DNA to messenger RNA.

Leucine Zipper Proteins

A type of protein that contains a specific motif which allows it to dimerize and bind DNA, playing key roles in regulating gene expression.