Which of the following works in association with cytoplasmic or nuclear receptors ?

Options

A. Insulin
B. Somatostatin
C. Oxytocin
D. Estrogen

Answer

To determine which of the following works in association with cytoplasmic or nuclear receptors, we need to analyze the types of hormones and their corresponding receptors.

### Step-by-Step Solution:

1. **Identify the Types of Receptors:**
- There are two main types of receptors:
- **Extracellular Receptors:** These are located on the cell membrane and interact with hormones that cannot pass through the cell membrane.
- **Intracellular (Nuclear) Receptors:** These are located inside the cell (either in the cytoplasm or nucleus) and interact with hormones that can pass through the cell membrane.

2. **Classify the Hormones:**
- **Protein Hormones:** These include insulin, somatostatin, and oxytocin. They are generally hydrophilic and cannot easily cross the cell membrane, thus they bind to extracellular receptors.
- **Steroid Hormones:** These include hormones like estrogen. They are lipophilic and can easily pass through the cell membrane, allowing them to bind to intracellular receptors.

3. **Analyze Each Option:**
- **Insulin:** A protein hormone that binds to extracellular receptors.
- **Somatostatin:** A peptide hormone that also binds to extracellular receptors.
- **Oxytocin:** Another peptide hormone that binds to extracellular receptors.
- **Estrogen:** A steroid hormone that binds to intracellular receptors (cytoplasmic or nuclear).

4. **Conclusion:**
- Among the options provided, **Estrogen** is the only hormone that works in association with cytoplasmic or nuclear receptors.

### Final Answer:
The correct answer is **Estrogen** (option 4).

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