Following a bolus administration of insulin, which of the following occurs?

INI-CET EXAM -2026

Biochemistry & Nutrition

Medium

Appeared in: INI-CET EXAM -2026

Explanation

Following an insulin bolus, insulin binds to receptors on skeletal muscle cells.
This binding triggers a signaling pathway that causes intracellular vesicles containing Glucose Transporter Type 4 (GLUT4) to move to the cell surface.
The fusion of these vesicles with the plasma membrane increases the number of active GLUT4 transporters.
This process significantly enhances the uptake of glucose from the bloodstream into the muscle cells for use or storage as glycogen.

Option A: The liver does not use GLUT4 for glucose uptake. Its primary glucose transporter is GLUT2.
Option C: Muscle cells use GLUT4, not GLUT2, for insulin-stimulated glucose uptake.
Option D: While the liver does use GLUT2 for glucose transport, this process is insulin-independent. The question asks for a direct consequence of an insulin bolus, which is the stimulation of GLUT4 translocation in muscle and fat tissue, a more prominent and regulated event.

Clinical Relevance

Nursing practice connection: Knowing Mechanism of insulin-stimulated glucose uptake helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
This mechanism is the foundation of insulin therapy for patients with diabetes. By administering insulin, nurses help facilitate glucose entry into cells, thereby lowering blood glucose levels.
In Type 2 diabetes, insulin resistance impairs this GLUT4 translocation process. Exercise is a key management strategy because muscle contraction can also stimulate GLUT4 to move to the cell surface, independent of insulin.
What if the patient had severe insulin resistance? Even with a bolus of insulin, the GLUT4 translocation would be significantly reduced, leading to a minimal drop in blood glucose and persistent hyperglycemia. This necessitates higher insulin doses or additional medications.

How to Approach the Question

First, identify the key components of the question: 'insulin bolus' and 'glucose uptake'. This points to the hormonal regulation of blood sugar.
Recall the different types of glucose transporters (GLUTs) and their primary locations and functions.
Specifically, differentiate between insulin-dependent (GLUT4) and insulin-independent (GLUT2) transporters.
Remember that GLUT4 is found in muscle and adipose tissue and is the primary target of insulin for glucose uptake.
Remember that GLUT2 is found in the liver and pancreas and is not directly regulated by insulin for transport.
Evaluate each option against this physiological knowledge to find the one that correctly matches the hormone (insulin), tissue (muscle), and transporter (GLUT4).

Concept Tested & Keywords

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