Answer
In addition to producing HCL, parietal cells also secrete a glycoprotein called Intrinsic Factor(IF). Intrinsic factor is necessary for the absorption of Vitamin B12 (Vit.B12) by the small intestine. Vit B12 and intrinsic factor bind to form a complex which is easily absorbed by receptor-mediated endocytosis.This is a very vital process because without IF hemoglobin cannot be synthesized . In a case where there is a hyposecretion of IF, a decrease in available Vit B12 . will result. The
consequent pathological syndromes would be hypoglobinemia, and anemia.
Work Step by Step
The risk of anemia as a result of hyposecretion of intrinsic factor increases with advancing age as the stomach mucosa atrophies. There is also a hereditary, autoimmune condition in which the gastric mucosa atrophies : this results in a decline in the production of IF, and in the production of hemoglobin. This often manifests as a syndrome called pernicious anemia
Pernicious anemia is reportedly more common in some Nordic (Scandinavian) populations. The therapy for all IF deficiency anemias is monthly intramuscular (im) injections of intrinsic factor; oral doses and/or sprays of IF are also used.
