Diabetes insipidus is caused by hyposecretion of

Options

A. Insulin
B. Vasopressin
C. Oxytocin
D. Thymosin

Explanation

**Step-by-Step Solution:**

1. **Understanding Diabetes Insipidus**: Diabetes insipidus is a condition characterized by excessive thirst and the excretion of large amounts of dilute urine. It is important to identify the underlying hormonal cause of this condition.

2. **Identifying the Hormone Involved**: The hormone that is primarily responsible for regulating water balance in the body is called Antidiuretic Hormone (ADH), also known as vasopressin. This hormone is secreted by the posterior pituitary gland.

3. **Function of ADH**: The main function of ADH is to minimize water loss by promoting water reabsorption in the kidneys. When ADH levels are adequate, the kidneys concentrate urine, leading to less water being lost in urine.

4. **Hyposecretion of ADH**: In diabetes insipidus, there is a hyposecretion (decreased secretion) of ADH. This leads to reduced water reabsorption in the kidneys, resulting in increased water loss through urine.

5. **Consequences of ADH Deficiency**: Due to the lack of ADH, the kidneys excrete a large volume of dilute urine, leading to symptoms such as excessive thirst (polydipsia) and frequent urination (polyuria).

6. **Conclusion**: Therefore, diabetes insipidus is caused by the hyposecretion of ADH (vasopressin).

**Final Answer**: Diabetes insipidus is caused by hyposecretion of **ADH (vasopressin)**.

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