Which hormone is mainly responsible for prostatic hypertrophy?
**Core Concept**
The question is testing the understanding of the pathophysiology of benign prostatic hyperplasia (BPH), a common condition in aging men characterized by an enlarged prostate gland. The correct answer involves identifying the hormone primarily responsible for stimulating the growth of prostate tissue.
**Why the Correct Answer is Right**
The main hormone responsible for prostatic hypertrophy is **dihydrotestosterone (DHT)**. DHT is a potent metabolite of testosterone that binds to androgen receptors in the prostate gland, leading to an increase in cell proliferation and hypertrophy. This process is mediated by the enzyme 5-alpha-reductase, which converts testosterone to DHT. Elevated levels of DHT are a key factor in the development of BPH, making it a primary target for pharmacological intervention.
**Why Each Wrong Option is Incorrect**
* **Option A:** Insulin-like growth factor-1 (IGF-1) is involved in cell proliferation and growth, but it is not the primary hormone responsible for prostatic hypertrophy.
* **Option B:** Parathyroid hormone (PTH) regulates calcium levels in the blood and has no direct role in prostate growth.
* **Option C:** Growth hormone (GH) stimulates growth and development, but it is not specifically involved in prostatic hypertrophy.
**Clinical Pearl / High-Yield Fact**
The use of 5-alpha-reductase inhibitors, such as finasteride, can reduce prostate size and alleviate symptoms of BPH by decreasing DHT levels. This is a key treatment strategy for managing this condition.
**Correct Answer:** D. Dihydrotestosterone (DHT)