Studies on the erythropoietic effect of testis of toad at a simulated high altitude (hypoxic exposure).

Sham operated control toads (non castrated) have shown increased activity in regard to the hematological parameters in comparison to the castrated toads kept under simulated hypoxic condition. Injection of plasma from sham operated control toads exposed to hypoxic stimulation initiates erythropoiesis in starved toads, whereas plasma from castrated exposed to the same hypoxic stimulation failed to do so. It can be suggested that in toad, testis is the only organ responsible for controlling erythropoiesis by secreting certain substance in the blood, which acts as erythropoietic stimulating factor (ESF), and the production of this factor was found to increase in response to the hypoxic stimulation in order to combat under low atmospheric condition.