Anti-diabetic effect of sulfonylureas is by reducing:
**Core Concept**
Sulfonylureas are a class of oral hypoglycemic agents used in the management of type 2 diabetes mellitus. Their primary mechanism of action involves the stimulation of insulin release from pancreatic beta cells.
**Why the Correct Answer is Right**
The anti-diabetic effect of sulfonylureas is primarily achieved by binding to and closing the ATP-sensitive potassium channels (K(ATP) channels) on the surface of pancreatic beta cells. This closure of K(ATP) channels depolarizes the beta cell membrane, leading to an influx of calcium ions and subsequent insulin release. The major enzyme responsible for the activation of sulfonylureas is the sulfonylurea receptor 1 (SUR1), which is a subunit of the K(ATP) channel.
**Why Each Wrong Option is Incorrect**
* **Option A:** Glucose uptake in peripheral tissues is not directly enhanced by sulfonylureas; their primary mechanism is insulin release.
* **Option B:** Sulfonylureas do not directly inhibit glucagon secretion; their primary effect is insulin release.
* **Option D:** Sulfonylureas do not primarily work by increasing insulin sensitivity; their primary mechanism is insulin release.
**Clinical Pearl / High-Yield Fact**
Sulfonylureas can cause hypoglycemia as a side effect, especially when used in combination with other insulin secretagogues or in patients with renal impairment.
**Correct Answer:** B. Glucose uptake in peripheral tissues is not directly enhanced by sulfonylureas; their primary mechanism is insulin release.