Studies on the erythropoietic effect of plasma from anemic toads both with and without testis.

Injection of plasma from experimentally induced anemic toad with intact testis increases erythropoiesis in starved toads evidenced by the increase of red blood cell, hemoglobin and hematocrit, whereas the plasma of castrated and phenylhydrazine-HCl treated anemic toad failed to do so. It can be suggested that the erythropoiesis stimulating factor (ESF) is produced from the testis of toad and the production of this factor (ESF) was found to increase during anemia in an attempt to correct the anemic condition.