Albumin (protein)
Albumin is a simple, water-soluble protein that plays a crucial role in the human body, primarily found in blood, egg whites, milk, and various animal and plant tissues. Produced in the liver, albumin constitutes about 50 to 60 percent of all blood proteins and serves multiple functions, including transporting hormones, nutrients, and medications throughout the body, as well as regulating fluid levels to prevent leakage from blood vessels. Albumin levels can provide vital indicators of a person's health; abnormal levels may suggest issues with liver or kidney function, nutrition, or other medical conditions.
The diagnostic measurement of albumin is typically conducted through blood tests, with normal levels ranging from 3.4 to 5.4 grams per deciliter. In medical scenarios, particularly for patients who produce insufficient albumin, it may be administered intravenously to help stabilize blood pressure and aid recovery from injuries. Research into alternative sources for albumin, including plant-derived options, shows promise, particularly with rice plants, offering potential new avenues for medical use. Understanding albumin's functions and its significance in health can provide insights into various medical conditions and treatments.
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Albumin (protein)
Albumin is a simple protein that is water soluble and coagulates, or clumps together, in heat. It is found in egg whites, milk, muscles and other animal tissue, some plant tissues, and blood. In blood, albumin helps gather other substances and transport them to various parts of the body. Albumin also helps prevent blood from leaking out of blood vessels. It is manufactured in the liver, and the kidneys partially regulate albumin levels in the body. Measuring the amount of albumin in blood can provide information about the health of those organs.
Background
The word albumin comes from the Latin word albumen, which means "white of an egg." Albumen was derived from the Latin word albus, which means "white." The white of an egg is still called albumen (with an "e" instead of an "i"). Although it contains nearly pure albumin protein, the terms are not interchangeable.
The existence of albumin was known for centuries, though its function was not well understood. Swiss physician Paracelsus observed albumin in urine in the fifteenth century. However, he thought it was milk formed during the digestive process, as a common thought at the time was that food was digested in stages in areas throughout the body. Over the next several centuries, physicians observed the effects of too much albumin in the body but did not fully understand what the protein was or how it affected the body.
In the seventeenth century, physicians studied the way blood separated into different forms outside the body. It included a part that clotted and formed small lumps and another thinner, watery substance. During the nineteenth century, physicians finally identified albumin specifically as the thinner substance found in blood and urine. Scottish-American physician William Charles Wells observed that blood contained a serum and that this serum—albumin—separated out when blood coagulated. Wells and others began to associate the presence of large amounts of this serum with conditions that affected the liver and kidneys. In the late nineteenth and early twentieth century, the development of new medical technologies allowed scientists to determine that albumin is a protein and to better understand its function in the body.
Overview
The albumin in blood is made by the liver and released continuously into the bloodstream. It is the main protein found in human blood; about 50 to 60 percent of all protein in blood is albumin. One of its most important functions is to collect other substances in the blood and take them where they need to go in the body. These substances include hormones, nutrients, enzymes, medications, and other materials necessary for healthy function.
Albumin also helps the body regulate its fluid levels. It pulls excess fluid from cells so it can be transported to the kidneys for removal. Albumin can absorb extra fluid in the blood to prevent it from leaking out of blood vessel walls. In addition, the protein that makes up albumin plays an important role in helping the body grow and repair and replace cells
The levels of albumin in blood or urine are used as indicators of a person's health. The liver uses proteins from food to produce albumin. The kidneys remove excess protein and other substances from the blood. If a person's blood or urine contains too much or too little albumin, it can indicate that the liver and/or the kidneys are not functioning properly. It also can mean that the person is not getting proper nutrition and is not consuming the proper amount of protein for albumin to be made. Other reasons for high or low levels of albumin include a severe infection or acute bodily stress from a heart attack, injury, surgery, or burn.
A physician will order an albumin level test, usually abbreviated ALB, if the person is jaundiced (has yellow skin) or has several other symptoms such as fatigue; unintentional weight loss; dark or discolored urine; swelling of the face, legs, or stomach; or other symptoms commonly associated with kidney or liver disease. Albumin can be detected in urine. However, for diagnostic purposes, the physician will usually order a blood test. Blood is drawn from the arm with a sterile needle and tested for the amount of albumin present.
The usual level for albumin is 3.4 to 5.4 grams per deciliter. Levels lower than this can indicate kidney or liver disease and other conditions, such as celiac disease or Crohn's disease. Additional testing will be done to determine the specific cause of the irregular albumin levels.
With certain medical conditions, albumin is administered as part of a treatment. Patients who produce too little albumin can receive does intravenously. Because it regulates fluid levels, albumin can help stabilize blood pressure in emergency situations. It can be used to treat patients with burns and other traumatic injuries who need to replace blood volume quickly. In addition, the protein contained in albumin can help with the healing process. Albumin often is extracted from donor blood and processed, much like plasma and other blood products, to be used when needed.
Research has determined that the albumin found in plant tissues and in the tissues of many animals is similar to human albumin. As a result, research has been conducted to try to grow a usable form of albumin from plant tissue that could replace or supplement the supplies extracted from donor blood for intravenous medical use. Efforts with potato and tobacco plants produced some results, but the most promising efforts have come from rice plants.
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