Oxygen Sensing and Erythropoietin mRNA Production in Isolated Perfused Rat Kidneys

In the adult, at the kidney is the major site of erythropoietin (Epo) synthesis (Jacobson et al. 1957), and recent studies showing that oxygen-modulated production of Epo mRNA and hormone occurs in isolated perfused kidneys (Ratcliffe et al. 1990; Pagel et al. 1990; Scholz et al. 1991) demonstrate that an oxygen-sensing system operates intrarenally. As increases in Epo levels can be achieved by stimuli in which systemic arterial oxygen tensions are normal, such as anaemia (Bondurant and Koury 1986; Erslev et al. 1987) or increased erythrocyte haemoglobin-oxygen affinity (Adamson and Finch 1975), it is likely that it is the changes in local tissue oxygen tension which activate the Epo oxygen-sensing machanism.