Erythropoietin expression in primary rat Sertoli and peritubular myoid cells

Kidney and liver are the major organs of erythropoietin (Epo) synthesis. Ho wever, Epo messenger RNA (mRNA) has been detected in several organs, such a s brain, lung, and testis. Furthermore, functional Epo receptors have been demonstrated on different cell types, including rat Leydig cells. The aim o f the study was to identify testicular cells expressing Epo mRNA and to qua ntitate its levels by competitive reverse transcriptase-polymerase chain re action (RT PCR). Besides whole testis, Epo transcripts were found in Sertol i and peritubular myoid cells, while no signal was detected in Leydig cells . Exposure of Sertoli cells to CoCl2 led to an increase of Epo mRNA level. Semiquantitative competitive RT PCR presented an increase in the level of E po mRNA in sertoli cells stimulated by follicle-stimulating hormone, while exposure of peritubular myoid cells cultures to testosterone reduced Epo mR NA expression. Due to the blood-testis barrier, basal expression of Epo sug gests a not yet defined function of this hormone in testis. (C) 2001 by The American Society of Hematology.