Previous studies which demonstrated that interstitial cells of the per
itubular capillary bed of the kidneys are the site of erythropoietin (
Epo) production have been performed in non-primate species. In this st
udy, kidneys from adult rhesus monkeys exposed to 18 h hypoxia (0.42 a
tm) with high serum (5685 mU/ml) and kidney (814 mU/g, includes serum
EPO in the kidney) levels of Epo were compared with a kidney from a no
nhypoxic normal rhesus monkey. Localization of Epo mRNA by in situ hyb
ridization was carried out with either anti-sense or sense RNA probes
generated from a 645 base pair KpnI-BglII fragment of a monkey Epo cDN
A. Epo mRNA was demonstrated only in interstitial cells in the peritub
ular capillary bed of the hypoxic and normal monkey kidneys utilizing
the antisense probe. The finding that the same type of cell that produ
ces EPO in mice, rats and sheep also produces EPO in a higher primate
species strongly supports the contention that renal interstitial cells
also produce EPO in the human.