Erythropoiesis-stimulating factor production by rabbit kidney cultures from "programmed" rabbits

Rabbit kidney tissue either from normal rabbits or from rabbits "programmed" by phlebotomy or varying periods of hypoxia was cultured and shown to release into the culture medium an erythropoietically active substance. The cultures established from rabbits programmed by 6-12 hr of hypoxia yielded the highest levels of erythropoiesis-stimulating activity.