ALBUMIN
In pathological levels albumin is used to evaluate:
1. Liver and renal disease
2. Blood osmotic pressure
3. Chronic disease states, which most patients have
4. Dehydration
5. Albumin decreases in acute inflammatory infectious processes
From a physiological standpoint, albumin is produced in the liver and is a primary byproduct of sterols and waxes. Its function is used to build and repair tissue. Albumin is responsible for 80 percent of the colloidal osmotic pressure between body tissues and blood cells. 75% of this control occurs inside the cells since most of the protein is intracellular.
When you have a decrease in albumin, the osmotic pressure becomes disturbed resulting in fluid transfer and edema. Since albumin influences water movement, it will also influence nutrient and mineral movement.
Albumin creates the permeability of the membrane to the osmolarity of the membrane. Therefore, substances can pass from a lesser concentration to a greater concentration. The flow is from the arterial capillaries to extracellular fluid, then from the extracellular fluid to the intracellular fluid, then from the intracellular fluid to the mitochondria. Then back via the same pathway in reverse via osmotic absorption into the veins.
Albumin is also a part of a complex buffer system, which accounts for 75% of things that need to be buffered to maintain acid-alkaline balance in the body. The most powerful buffer system out of the four including, the bicarbonate system (HCO3-), the phosphate buffer system, and the liver (nitrogen/urea), the proteins of the cells and plasma, rein supreme. The protein buffer system works by controlling blood Hydrogen (H+) ion homeostasis. Both intracellular and extracellular proteins have negative charges and can serve as buffers for alterations in hydrogen ion concentration. However, because most proteins are inside cells, this primarily is an intracellular buffer system.
Hemoglobin (Hb) a globular protein is an excellent intracellular buffer because of it’s ability to bind with Hydrogen ions forming a weak acid and carbon dioxide (CO2) bond. After oxygen is released in the peripheral tissues, hemoglobin binds with CO2 and H+ ions. As the blood reaches the lungs these actions reverse themselves. Hemoglobin binds with oxygen, releasing the CO2 and H+ ions. The H+ ions then combine with bicarbonate (HCO3) ions to form carbonic acid (H2CO3). The H2CO3 breaks down to form water (H2O) and carbon dioxide (CO2), which are excreted via expiration through the lungs.
Increases in albumin cause arteries to sclerose and a decrease in albumin causes veins to sclerose.
Albumin is also a transporter of minerals and accounts for 70% of the bound calcium.
Magnesium also binds to albumin and since it has a lower specificity for the receptors it creates more free magnesium in the plasma.
Calcium, magnesium, and phosphates continuously enter the plasma via the kidneys, the intestinal brush borders and the ruffled border of the bone.
Albumin is also responsible for transporting copper, zinc, and nickel.
By controlling the transport of these minerals, albumin is the carrier of choice.
The following glands are associated with albumin:
1. The parotids
2. The head of the pancreas
3. The endo-reticular portion of the liver
4. Kidneys
Therefore, the function or malfunction of anyone of those glands/organs or combinations thereof can lead to imbalances in albumin levels.
