Myoglobin is a type of protein that is found in various muscle cells of humans and animals. They are rich in iron and this why they have a reddish color. Myoglobin is also composed of more than 150 amino acids that are water soluble and have a structure similar to that of another protein called hemoglobin. This protein also has the tendency to bind with oxygen which serves a very important purpose for muscle tissue.
In terms of function, myoglobin performs two core functions. One core function is related to its iron content. This protein lends itself in providing iron to various muscle cells in the body of vertebrates, humans and animals included. In the case of human muscles for example, myoglobin can usually be found supplying iron to the heart muscles and various skeletal muscles all throughout the body. Another core function of myoglobin involves its affinity to bind with oxygen. In terms of skeletal muscle health, myoglobin provides reserve oxygen in case there is depletion of this important element. This extra oxygen store provided by myoglobin is especially essential for so-called endurance muscles. These types of muscles are typically red in color because of their high myoglobin content. In cases when these muscles are pushed to the limit during prolonged exercise, there may not be enough oxygen to supply their metabolic needs. When this condition happens, the myoglobins present in these skeletal muscles will then be activated to release the much-needed emergency oxygen stores.
When there is muscle injury, myoglobin levels in skeletal and cardiac muscle may be too high. Whenever they are released in very high concentrations, the kidneys will be forced to process and filter them properly. With too much myoglobin, the kidneys may suffer from high toxicity secondary to elevated myoglobin levels. For cardiac muscles, myoglobin levels are also useful in terms of detection of possible heart problems like acute myocardial infarction.