Molecular action of erythropoietin on RNA synthesis: 30 years of study.

Studies on erythropoietin (Epo) are briefly reviewed in their historical perspective from mid 19th century until its identification as a product of genetic recombination and its clinical trials in 1987. Our own work throughout three decades deals mainly with Epo action on RNA biosynthesis in rat bone marrow. Results show that Epo participation as a fundamental compound in the erythropoietic process, inducing the biosynthesis of a giant RNA probably with hnRNA characteristics, which is processed to functional RNA with the participation of testosterone (Te). Despite the so many experimental data available at present, there is still no conclusive evidence allowing to define the specific molecular mechanisms of action of both hormones at transcriptional level. A model is postulated to explain the effects of Epo and Te on RNA biosynthesis. Finally, the implications of present knowledge for the conceptual approach and design of future work are discussed.