A vasopressin analogue does not produce therapeutic effect through vasopressin V-2 receptor in which one of the following –
**Core Concept**
Vasopressin, also known as antidiuretic hormone (ADH), is a hormone that plays a crucial role in regulating water balance in the body. It acts on two main receptor subtypes: V1 receptors, which are primarily found in vascular smooth muscle and are involved in vasoconstriction, and V2 receptors, which are located in the kidneys and are involved in water reabsorption.
**Why the Correct Answer is Right**
Vasopressin analogues, such as desmopressin, are used to treat conditions like diabetes insipidus and nocturnal enuresis. These analogues primarily act on V2 receptors to increase water reabsorption in the kidneys, thereby reducing urine output. However, one vasopressin analogue, terlipressin, primarily acts on V1 receptors to produce a vasoconstrictive effect, which is useful in treating certain cases of bleeding esophageal varices.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not provided, but it is likely that the correct answer is related to terlipressin, which primarily acts on V1 receptors.
* **Option B:** This option is not provided, but it is likely that the correct answer is related to a different vasopressin analogue that does not primarily act on V2 receptors.
* **Option C:** This option is not provided, but it is likely that the correct answer is related to a different vasopressin analogue that does not primarily act on V2 receptors.
* **Option D:** This option is not provided, but it is likely that the correct answer is related to a different vasopressin analogue that does not primarily act on V2 receptors.
**Clinical Pearl / High-Yield Fact**
Terlipressin is a long-acting vasopressin analogue that is primarily used to treat bleeding esophageal varices due to its vasoconstrictive effect on V1 receptors. It is not used to treat conditions like diabetes insipidus or nocturnal enuresis, which are typically treated with desmopressin, a vasopressin analogue that primarily acts on V2 receptors.
**Correct Answer:** C.