Question

Only certain cells in the body are target cells for the steroid hormone aldosterone. Which of the following is the best explanation for why these are the only cells that respond to this hormone?

• A. Only target cells are exposed to aldosterone
• B. Only target cells contain receptors for aldosterone
• C. Aldosterone is unable to enter non-target cells
• D. Non-target cells destroy aldosterone before it produces its effect

Answer 1

The correct option is B Only target cells contain receptors for aldosterone

Aldosterone is a steroid hormone (mineralocorticoid) that regulates salt - water balance in the body. Steroid hormones are lipophilic. They cross the cell membrane but can function only when they bind to specific receptors that are present only in the target cell. The hormone-receptor complex then binds to regions of DNA and activates transcription of that particular region of DNA. This produces messenger RNA (mRNA), which then codes for the production of specific proteins. These proteins often have an enzymatic activity that changes the metabolism of the target cell in a specific fashion.