Which of the following hormones is not released by pars distails, in frog ?

Options

A. Growth hormone
B. Prolactin
C. Melanocyte stimulating hormone
D. Luteinizing hormone

Answer

To determine which hormone is not released by the pars distalis in frogs, we need to analyze the functions and origins of the hormones listed in the options.

### Step-by-Step Solution:

1. **Understand the Structure of the Pituitary Gland**:
- The pituitary gland is divided into two main parts: the anterior pituitary (adenohypophysis) and the posterior pituitary (neurohypophysis).
- The anterior pituitary includes the pars distalis and pars intermedia, while the posterior pituitary is also known as the pars nervosa.

2. **Identify the Hormones Released by the Pars Distalis**:
- In frogs, the pars distalis is responsible for producing several hormones. Common hormones produced by the pars distalis include:
- Growth Hormone (GH)
- Luteinizing Hormone (LH)
- Follicle Stimulating Hormone (FSH)
- Adrenocorticotropic Hormone (ACTH)
- Thyroid Stimulating Hormone (TSH)

3. **Identify the Hormones Released by the Pars Intermedia**:
- The pars intermedia is known to produce hormones such as:
- Melanocyte Stimulating Hormone (MSH)

4. **Review the Options Given**:
- The options provided are:
1. Growth Hormone
2. Prolactin
3. Melanocyte Stimulating Hormone
4. Luteinizing Hormone

5. **Determine Which Hormone is Not Released by Pars Distalis**:
- From the analysis, we see that:
- Growth Hormone, Luteinizing Hormone, and Follicle Stimulating Hormone are released by the pars distalis.
- Melanocyte Stimulating Hormone is released by the pars intermedia.
- Prolactin is not typically released by the pars distalis in frogs.

6. **Conclusion**:
- The hormone that is not released by the pars distalis in frogs is **Prolactin**.

### Final Answer:
**Prolactin**