Question

Some of the hemoglobin in the blood due to intravascular hemolysis is returned to the spleen by haptoglobin molecules, thus depleting serum haptoglobin. What is the function of haptoglobin in this process?

1) Transporting oxygen to the tissues
2) Binding to free hemoglobin and preventing its oxidative damage
3) Producing red blood cells
4) Breaking down hemoglobin into its constituent parts

Answer 1

Haptoglobin binds to free hemoglobin resulting from intravascular hemolysis to prevent oxidative damage and facilitate the recycling of hemoglobin components in the spleen, thus fulfilling option 2 of the provided choices.

Step-by-step explanation:

The function of haptoglobin in the process described is not to transport oxygen to the tissues, produce red blood cells, or breakdown hemoglobin into its constituent parts. Instead, haptoglobin's primary role is to bind to free hemoglobin released into the bloodstream from lysed red blood cells (intravascular hemolysis) to prevent its oxidant damage to vessels and tissues. By forming a complex with free hemoglobin, haptoglobin prevents the loss of iron and heme degradation products through the kidneys and facilitates the return of hemoglobin to the spleen, where its components can be recycled. In summary, the correct function of haptoglobin is option 2) Binding to free hemoglobin and preventing its oxidative damage.