<Table> <Tr> <Td_colspan="2"> View / Edit Human </Td> <Td_colspan="2"> View / Edit Mouse </Td> </Tr> </Table> <Tr> <Td_colspan="2"> View / Edit Human </Td> <Td_colspan="2"> View / Edit Mouse </Td> </Tr> <P> Myoglobin (symbol Mb or MB) is an iron - and oxygen - binding protein found in the muscle tissue of vertebrates in general and in almost all mammals . It is related to hemoglobin, which is the iron - and oxygen - binding protein in blood, specifically in the red blood cells . In humans, myoglobin is only found in the bloodstream after muscle injury . It is an abnormal finding, and can be diagnostically relevant when found in blood . </P> <P> Myoglobin is the primary oxygen - carrying pigment of muscle tissues . High concentrations of myoglobin in muscle cells allow organisms to hold their breath for a longer period of time . Diving mammals such as whales and seals have muscles with particularly high abundance of myoglobin . Myoglobin is found in Type I muscle, Type II A and Type II B, but most texts consider myoglobin not to be found in smooth muscle . </P>

A protein found in muscle that can bind to and store oxygen