What is Cholecystokinin? Let's talk about it simply!

Hello! How are you? Today we are going to talk about a small but very important chemical messenger in our body. It is called cholecystokinin. Although the name may seem a bit long, it is essential for our digestive process. Let's see what it does, how it works, and how important it is to our body?

What is this cholecystokinin?

Simply put, cholecystokinin is a hormone . Do you know what hormones are? They are like little messengers that carry messages from place to place in our bodies. This hormone called cholecystokinin is mainly produced by cells in your small intestine , especially after we eat. That is why it is sometimes called pancreozymin. It is named so because it works in the pancreas. But surprisingly, this cholecystokinin is also present in our brain and central nervous system . Scientists are still figuring out exactly what it does there. But its role in digestion is enormous.

How does cholecystokinin begin to be secreted?

Imagine that you have eaten a delicious meal. Maybe a meat curry with rice, or a piece of fish, some lentils, a coconut sambol... The food you eat first goes to the stomach. It is digested there for a while, and then little by little it starts to reach the first part of the small intestine, the duodenum . It is like a train coming to a station. Then, there are special cells in the walls of your duodenum, like detectives. They are called I-cells . These I-cells have the amazing ability to recognize the proteins and fats (that is, meat, fish, eggs, milk, oils) in the food you eat. As soon as they see them, these `(I-cells)` think, "Oh, now is the time to get down to business! We need to get our friend cholecystokinin out quickly," and they make it and release it directly into the blood. From there, its important journey begins.

What does cholecystokinin do to our body?

This is where the real work happens after cholecystokinin gets into the blood. It doesn't just sit there. It travels through the blood, goes to each organ, and does a lot of important work.

What it does during digestion

Let's see how important a role cholecystokinin plays in digestion:

• Causes the gallbladder to contract: It tells your gallbladder, "Okay, now you have the bile inside you."Put some in the small intestine. It's time to get to work!" Don't be surprised, the name 'cholecystokinin' means 'to move the gallbladder'. This bile is what helps dissolve the oils, or fats, that we eat, and break them down into small droplets. Just like we use soap to wash dishes.
• Stimulates the pancreas: It also sends a signal to the pancreas, saying, "You should also send your digestive enzymes to the small intestine. There's a big job to do here." The other name, "pancreozymin," is derived from this work related to the pancreas .
• Protein and fat breakdown: The bile from the gallbladder and the enzymes from the pancreas work together to break down the proteins and fats in the food we eat into smaller pieces so that they can be absorbed by the body. This is like breaking a large stone into smaller pieces.
• Controls gastric emptying: While this work is happening in the small intestine, cholecystokinin tells the stomach, "Don't worry, wait a minute. Don't send a new batch of food into the small intestine until the previous food has been digested." This is called gastric emptying suppression . This means that the small intestine doesn't get a large amount of food at once, but rather has time to digest it properly.
• Reduces appetite : During digestion, cholecystokinin makes our stomach feel full. It also stimulates the vagal nerves in the stomach wall, sending a signal to the brain, "Enough, I'm full, don't eat anymore." This is why we feel full shortly after eating.
• Peristalsis begins: Finally, this digested food needs to be moved down the intestines . This is helped by the rhythmic contraction and relaxation of the muscles in the intestines, called peristalsis . It's like pushing the food through the intestines .

Imagine how smoothly this one hormone helps our digestive process run!

Effects on the brain and nervous system

In addition to helping with digestion, cholecystokinin has also been found to play a role in our brain and central nervous system. This is still being researched, but what has been discovered so far is very important. In particular, it may help with anxiety andIt seems to be linked to mental health conditions like panic attacks . Some studies have shown that increased levels of cholecystokinin in the brain increase anxiety. This is a bit complicated, but it is clear that it also has an effect on our emotional regulation. It has also been reported to be involved in controlling body temperature, or thermoregulation . It is said that if injected into the brain, it will cause a fever, and if injected into other parts of the body, it will cause hypothermia, a condition in which the body temperature drops. However, further research is needed to understand this exactly.

Where is cholecystokinin found in our body?

Like other hormones, cholecystokinin travels throughout our bodies in our bloodstream . It "talks" to different organs through special receptors on the cells of those organs. These receptors are like doors. Only when the key called cholecystokinin is present do the doors open, and then the cell receives the message. In our digestive system, cholecystokinin (CCK) receptors are found in the muscles of the gallbladder, the lining of the stomach and intestines, and the pancreas. These receptors can also be found in various parts of the brain and central nervous system.

What are the diseases associated with cholecystokinin?

There are some diseases in which low levels of cholecystokinin have been found. However, it is not yet clear whether this is a consequence of the disease or a cause of the disease. Research is still ongoing on this. For example, low levels of cholecystokinin may be associated with conditions such as gastroparesis , a condition in which the stomach does not empty properly and food is stuck in the stomach, and biliary dyskinesia, a condition in which the gallbladder does not function properly and does not release bile properly. In addition, scientists are investigating how various variations in the genes involved in the production of cholecystokinin are associated with some anxiety disorders and metabolic disorders. Some research suggests that these genetic variations may alter the way cholecystokinin interacts with the brain and controls signals of anxiety or hunger.

What is the relationship between cholecystokinin and obesity?

Obesity, or extreme obesity, is a problem for many people today. Scientists are also actively investigating whether there is a link between obesity and cholecystokinin. Some of the findings are quite surprising. For example, it has been found that people with a particular variant (change) in the cholecystokinin gene are about 60% more likely to become obese than others. There is also some evidence that people with severe obesity (class III obesity), that is, very fat people, have reduced sensitivity to cholecystokinin. This means that even though they have cholecystokinin in their bodies, they may not be able to properly sense the 'fullness' signal it gives them. Cholecystokinin works with another hormone called leptin to control hunger. People with obesity may have an imbalance between hunger and fullness signals in their brains. Therefore, understanding cholecystokinin may also help in finding treatments for obesity.

What is this cholecystokinin test?

A cholecystokinin test involves giving your gallbladder a medicine called cholecystokinin to stimulate it to contract. Sometimes this is done as part of a HIDA scan, which is a special type of nuclear medicine imaging test. Don't be alarmed by the name, this is a very safe test. Here's what happens: 1. First, a technician injects a small amount of a radioactive isotope, or tracer, into your vein. It's like painting a few roads inside your body and looking at what's going on along them. 2. This tracer travels to your liver and biliary system (gallbladder, bile ducts). 3. Then, a special camera (scanner) is used to capture the radiation emitted by this tracer and display images on a computer screen. These images allow the doctor to see how the bile is formed and how it travels. If your doctor wants to see what happens when your gallbladder contracts, he or she may add cholecystokinin to the HIDA scan as an additional step. At that time, the technician will inject cholecystokinin into your vein. Then, more images are taken. Just like the cholecystokinin that is naturally produced in your intestines, the injected cholecystokinin stimulates the gallbladder to contract. Doctors order this test to see if there is a problem with your gallbladder's function and whether it is releasing bile properly.

Are there any medical treatments for cholecystokinin?

So far, there is no medical treatment that directly uses cholecystokinin. That is, cholecystokinin is not given as a cure for a disease. However, it has been used to discover and test new drugs. For example, researchers are trying to create drugs that are similar to cholecystokinin in reducing appetite and helping with weight loss. Also, cholecystokinin has a special part called CCK-4 . This CCK-4 is known to cause people to feel anxious and panicky. Therefore, scientists sometimes use CCK-4 to test how effective new anti-anxiety drugs are.

The most important things we need to remember (Take-Home Message)

So, from what we've talked about cholecystokinin, you can remember some of the most important things. Now you understand how big a job this little hormone does inside our bodies, right?

• Cholecystokinin is a hormone that is essential for the digestive process . It "talks" to all the organs involved in digestion, such as the gallbladder and pancreas, and helps them do their job properly.
• Doctors also use it as a reliable stimulant to test gallbladder function.
• It also helps control hunger . It has also been found that impaired function of cholecystokinin may be associated with conditions such as obesity.
• Scientists are continuing to study its role in the brain and nervous system, especially its relationship to conditions such as anxiety and panic disorders.

So, our bodies are truly amazing machines! It's amazing how much of a difference these little things can make to our health, isn't it? Take care of your body, and these little friends will take care of you!

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Cholecystokinin, Cholecystokinin, Hormone, Digestion, Gallbladder, Pancreas, Hunger, Obesity, HIDA scan