What is the primary mechanism of action for insulin?

What is the primary mechanism of action for insulin?

• A. Inhibition of hepatic glucose production
• B. Translocation of glucose receptors to extracellular for "capture" of glucose in target tissue
• C. Promotion of glycogenolysis
• D. Stimulation of glucagon secretion

Answer: (B)

The primary mechanism of action for insulin involves the translocation of glucose transporters, specifically GLUT4, to the plasma membrane of target tissues such as muscle and adipose tissue. This action facilitates the "capture" of glucose from the bloodstream into these tissues. When insulin binds to its receptor on the cell surface, it initiates a signaling cascade that promotes the movement of GLUT4 transporters from intracellular vesicles to the cell membrane. This process increases the uptake of glucose, effectively lowering blood glucose levels postprandially. In the context of glucose metabolism, this mechanism is crucial as it allows cells to respond efficiently to elevated levels of glucose, enabling them to utilize glucose for energy production or to store it as glycogen. Insulin's role in enhancing glucose uptake is fundamental to its function as a hormone in regulating carbohydrate metabolism and overall energy homeostasis in the body.

The primary mechanism of action for insulin involves the translocation of glucose transporters, specifically GLUT4, to the plasma membrane of target tissues such as muscle and adipose tissue. This action facilitates the "capture" of glucose from the bloodstream into these tissues. When insulin binds to its receptor on the cell surface, it initiates a signaling cascade that promotes the movement of GLUT4 transporters from intracellular vesicles to the cell membrane. This process increases the uptake of glucose, effectively lowering blood glucose levels postprandially.

In the context of glucose metabolism, this mechanism is crucial as it allows cells to respond efficiently to elevated levels of glucose, enabling them to utilize glucose for energy production or to store it as glycogen. Insulin's role in enhancing glucose uptake is fundamental to its function as a hormone in regulating carbohydrate metabolism and overall energy homeostasis in the body.