Erythropoietin is secreted from:
In adults, about  85% of the erythropoietin comes from the kidneys and 15% from the liver. 
Erythropoietin is produced by interstitial cells in the peritubular capillary bed of the kidneys and by perivenous hepatocytes in the liver.
Juxtaglomerular cells
Macula densa
Interstitial cells
Glomerulus