Secretin is a peptide hormone produced by the cells of the duodenum and small intestine. Plays a vital role in controlling food digestion. What are its functions in the human body? How is secretin used in laboratory diagnostics? What is a secretinism attempt?
Secretinis one of the gastrointestinal hormones that control the digestion of food. This means that it is a form of a chemical message that is sent from one organ to another. Thanks to this method of communication, all elements of the gastrointestinal tract work together smoothly. As a result, the food is digested efficiently, and we do not feel unpleasant intestinal ailments.
How and when is secretin secreted?
This substance is secreted by the intestines and duodenum when acidic food reaches them from the stomach. Hydrogen ions are the chemical stimulus that stimulates the production of secretin.
Duodenal cells secrete an inactive form of this hormone - prosecretin. This substance is converted into secretin when it comes into contact with the acidic pH of the food from the stomach.
How does secretin work?
The role of this hormone is to stimulate the production of pancreatic juice, bile and intestinal juice. The concentration of secretin rises when the food leaves the stomach and requires digestion in subsequent sections of the gastrointestinal tract with the use of appropriate digestive enzymes.
This substance also inhibits gastric and intestinal peristalsis. This means that it slows down the flow of food through the digestive tract. This allows food to remain in the small intestine and duodenum until it is completely digested. At the same time, no new food with an acidic pH is flowing from the stomach that could disturb digestion.
Secretin helps regulate the pH of the duodenum. The mechanism of this activity is based on the inhibition of gastric acid secretion by the parietal cells in the stomach.
Another important role of secretin is to stimulate the liver to produce bile, which is used in the digestive tract to emulsify fats. The process works by breaking down large clusters into tiny particles. After emulsification, lipids become sensitive to their digesting enzyme, which is pancreatic lipase. Ultimately, the secretin stimulates the productionsbile stimulates the digestion of fats.
Does secretin only affect digestion?
Secretin has long been treated as a hormone whose properties are limited only to the effects on the gastrointestinal tract. In 2007, however, its meaning for our body was discovered. Secretin has been found to play a role in water management, affecting the hypothalamus, pituitary gland and kidneys.
This hormone modulates the transport of water and electrolytes in the cells of the pancreatic duct, liver cholangiocytes and epididymal epithelial cells. It has been found to play a role in the vasopressin-independent regulation of renal water reabsorption.
How does secretin affect your appetite?
Secretin and its receptor are also found in the nuclei of the hypothalamus, including the periventricular and arcuate nucleus. These are the regions of the brain that control the body's energy requirements. They are responsible for the feeling of hunger and satiety.
It has been proven in studies on mice that injecting these animals with secretin into the blood reduces their food consumption. This proves that this hormone induces a feeling of fullness. This regulation is due to the fact that secretin is secreted when there is food in the digestive tract at the digestive stage.
How was the existence and functions of a secretin discovered?
Secretin was the first discovered and described hormone in human history. Its properties were studied by William Bayliss and Ernest Starling in 1902. Their work focused on how the nervous system influences the digestive process.
Researchers knew that the pancreas secreted digestive juices in response to food passing through the pyloric sphincter into the duodenum. In the course of the tests, they severed all pancreatic nerves in the experimental animals. This was to determine whether the work of this organ is directly controlled by nerve impulses. It turned out that the work of the pancreas was independent of the nerve connections.
Following this discovery, scientists in further work established that the intestinal mucosa secretes a substance that is responsible for stimulating the work of the pancreas. They named the identified chemical secretin. It was originally referred to as a "chemical messenger" in the human body. The concept of a hormone in medicine did not appear until 1905.
What is the use of secretin in medicine? Secretin Trial
Recombinant human sectinhas been available for diagnostic purposes since 2004.
The secretin is administered to the patient during diagnostic tests of pancreatic function. The hormone is given as an injection. In the next stage of the examination, a specialistobserves the pancreas using magnetic resonance or other non-invasive imaging methods.
This study is calledsecretin test . The purpose of this test is to determine the secretory capacity of the pancreas. This test has a high diagnostic value, but is expensive and time-consuming. In the case of liver disorders, the results may be distorted.
Can secretin be used in the treatment of autism?
In the 1990s, there were high-profile theories about the use of secretin as a drug in the treatment of autism. These concepts resulted from the hypothesis about the intestinal connection with the brain, which is important in the genesis of this disorder. There have been many clinical studies on the use of secretin in the treatment of autism.
The results clearly indicated that the treatment of autism with secretin was not effective.
About the author
Sara Janowska, MA in pharmacyPhD student of interdisciplinary doctoral studies in the field of pharmaceutical and biomedical sciences at the Medical University of Lublin and the Institute of Biotechnology in Białystok. A graduate of pharmaceutical studies at the Medical University of Lublin with a specialization in Plant Medicine. She obtained a master's degree defending a thesis in the field of pharmaceutical botany on the antioxidant properties of extracts obtained from twenty species of mosses. Currently, in his research work, he deals with the synthesis of new anti-cancer substances and the study of their properties on cancer cell lines. For two years she worked as a master of pharmacy in an open pharmacy.
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