PAROXYSMAL myoglobinuria is a disease characterized clinically by muscle pain, fever, and the excretion of dark urine. Pathologically, the disease is a result of an apparently spontaneous muscle injury with the excretion of muscle hemoglobin (myoglobin) in the urine.
The properties of myoglobin and its occurrence in man have been thoroughly reviewed in a recent monograph by Biörck.1 This includes the chemistry and physiology of myoglobin. Myoglobin is a hemoglobin in the sense that it is a complex compound of protoporphyrin, ferrous iron, and globin. A comparison of the two pigments follows (data from Biörck1):The differences in the molecular weight of hemoglobin and myoglobin probably explain the low renal threshold value for myoglobin. This low renal threshold for myoglobin in turn probably explains why we find the greater part of the pigment in the urine rather than in the plasma in those pathologic states in which myoglobin
SCHAAR FE. PAROXYSMAL MYOGLOBINURIADescription of a Case and a Review of the Literature. AMA Am J Dis Child. 1955;89(1):23–30. doi:10.1001/archpedi.1955.02050110039006