Biology Reference
In-Depth Information
The role of kidney and bone marrow in erythropoiesis
In the fetus, the liver is the primary site of endogenous EPO production [26].
In the adult, EPO is produced primarily (i.e., >90%) in the adult kidney [25,
27]. The liver [28, 29] and the brain [30] both synthesize some EPO, but the
amount produced by these tissues alone is insufficient to maintain adequate
erythropoiesis. Thus, kidney disease causes anemia due to loss of the main
source of EPO production.
An oxygen sensor within renal cells detects the oxygen content of the blood
and the kidney regulates the amount of EPO released into the blood (Fig. 1).
The hormone acts on red blood cell precursor cells in the bone marrow to stim-
ulate their proliferation and maturation and to increase the number of red
blood cells in the peripheral circulation. The feedback loop is completed when
the kidney cells recognize the change in oxygen delivery secondary to the
Figure 1. Relationship of kidney and bone marrow in production of red blood cells. (Figure courtesy
of Amgen.)
