What are insulin receptors (IR)?
Insulin receptors are large proteins outside the cell membrane, which allow cells to bind with insulin in the bloodstream. Ever since insulin was discovered, in addition to its function in regulating glucose uptake from the bloodstream, there has been a lot of attention paid to insulin, including its structure and how it interacts with IR in the body. Insulin is a naturally occurring hormone that helps to regulate blood glucose levels, as mentioned above. Glucose is a form of sugar, which is one of the main sources of energy for the body. When you eat carbohydrate-rich foods, glucose will get absorbed into your bloodstream. The body will then stimulate the pancreas to release insulin, which will bind with insulin receptors. IR are present on the surfaces of the body’s cells, such as the muscle, liver and fat cells. When this happens, the body cells will absorb glucose from the bloodstream. This helps to reduce high blood glucose levels.
Insulin receptors are ligand receptors and part of the tyrosine kinase family of receptors. Both are vital regulators in cell growth and metabolism; however, compared to other members of these receptor families, IR have unique biochemical and physiological properties. The core physiological function of IR is mainly metabolism, while other receptors in the tyrosine kinase receptor family mainly work on cell growth. IR have several functional parts. Usually, two parts of the protein chain come together to form a receptor site just outside the cell. This receptor site is where insulin binds and opens the cells that allow glucose to enter.
What happens if insulin receptors don’t properly function?
In case there is a problem with insulin signaling, the body may fail to properly regulate blood sugar levels.
This may lead to symptoms of diabetes such as:
- Blurred vision
- Excessive thirst
- Frequent urination
- Wounds that heal slowly
- Increased hunger
- Skin infections
- Unexplained weight loss
The cells of people with diabetes cannot absorb sugar from the bloodstream because their bodies become resistant to insulin or cannot produce insulin. Insulin resistance is a condition that happens when the insulin receptors do not properly respond to the effects of insulin. Usually, insulin binds to the IR outside the cells. When this happens, it activates the cell’s sugar transporter molecules to open the door for glucose to enter the cell. People with diabetes type 2 diabetes experience insulin resistance, which reduces the cells’ response to insulin. As a result, the cells cannot absorb glucose from the bloodstream properly. This leads to high blood sugar levels which can be life threatening if not treated. Diabetes can be treated through adoption of proper diet, exercise and medication.