What You Should Know About Insulin Receptors
What is insulin?
Insulin is a hormone produced by an organ in your body known as the pancreas, which is located behind the stomach. This hormone helps transport glucose into the body’s cells and tissues where it can then be used for energy, or get stored for later needs. Glucose is a form of sugar. Without insulin, glucose cannot enter the body’s cells, which leads to a build up of glucose in the blood stream. This causes high blood sugar levels. If left untreated, high blood sugar can cause health complications such as blindness, kidney problems and nerve damage. People with type 1 diabetes make little or no insulin as a result of immune system mistakenly attacking the beta cells in the pancreas. Therefore, they need to take insulin so that they can survive. People with type 2 diabetes, which is a chronic condition where the body does not make enough insulin, or is resistant to it, may also need to take insulin. However, many patients with type 2 diabetes can manage their condition by eating a proper diet, getting regular exercise and taking oral diabetes medication. If these things are not enough to sufficiently lower blood sugar levels, people with type 2 diabetes may require insulin therapy.
Insulin comes in solution form which is normally injected under the skin. This man-made insulin replaces the function of the natural hormone which is to control blood glucose levels. If there is too much insulin in the bloodstream, insulin will signal the body to store the excess glucose in the liver. If your blood sugar levels drops as a result of stress or not eating for hours, glucagon will signal the liver to release the excess glucose into the bloodstream so that your body has energy to use. Both glucagon and insulin are hormones that are recognized by receptors outside the body’s cells.
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.
Disclaimer: Please note that the contents of this community article are strictly for informational purposes and should not be considered as medical advice. This article, and other community articles, are not written or reviewed for medical validity by Canadian Insulin or its staff. All views and opinions expressed by the contributing authors are not endorsed by Canadian Insulin. Always consult a medical professional for medical advice, diagnosis, and treatment.