You are an attending physician supervising a new resident. Together, you decide to treat a patient with a steroid drug. The resident administers the drug and watches the patient anxiously. "It's not working," he mutters. How do you respond?

Question

A.  "You're right, it doesn't seem to be working. Let's increase the dose, since we need to achieve high steroid levels in the blood."
B.  "Why don't you go on your rounds and come back? Steroid hormones need several hours to work, since they regulate gene expression. Transcription and translation take time."

C.  "We forgot to administer the carrier protein to get the drug across the cell membrane. We can add that now."
D.  "Let's grab a cup of coffee and then check again. Activating the G-protein coupled receptor and its downstream kinase cascade can take several minutes."

Clarify Question
What is the key concept addressed by the question?
What type of thinking is required?

Gather Content
What do you already know about hormones? What other information is related to the question?

Choose Answer
Given what you now know, what information is most likely to produce the correct answer?

Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

B.  "Why don't you go on your rounds and come back? Steroid hormones need several hours to work, since they regulate gene expression. Transcription and translation take time."

Clarify Question
What is the key concept addressed by the question?
        · Response time of steroid drugs.
What type of thinking is required?
            o This is an evaluate question because you have to consider each response to assess its accuracy in understanding the mode of action of lipophilic hormones.

Gather Content
What do you already know about hormones? What other information is related to the question?
        · Hormones deliver their signals through the bloodstream. As blood travels to all tissues, they bind to either cell-surface receptors or intracellular receptors. Lipophilic hormones, like steroids, can travel through the cell membrane while hydrophilic hormones such as proteins cannot cross the cell membrane and so must bind to cell-surface receptors. Since the treatment drug is a steroid, it will directly cross the cell membrane and interact with DNA to regulate genes. The process of transcription and translation take time, so the effect of the drug will not be immediate.

Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
        · The drug that is being administered is a steroid. Steroid hormones cross the cell membrane to interact with DNA to regulate gene expression. No carrier protein is needed so that answer is incorrect. Similarly, no G-protein coupled receptor or downstream kinase cascade is needed, so that answer is also incorrect. Gene expression involves transcription of the DNA into mRNA and translation of the mRNA into protein. As this process takes some time, you should not expect the drug to have an immediate effect. Increasing the dose without giving the original dose time to have an effect could be dangerous.

Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        · Answering this question correctly depended upon understanding how lipophilic hormones work. If you got the answer correct, great! If not, which answer did you choose? Did you think that lipophilic hormones would be associated with G-proteins or need some other means (like a carrier protein) to get across the cell membrane? Lipophilic (or hydrophobic) molecules can readily cross the cell membrane, so such mechanisms are not needed. Did you think that increasing the dosage would be useful? High levels of steroids in the blood are not needed for them to be effective.