Fenoterol stimulates human erythropoietin production via activation of the renin angiotensin system

AIMS: The present study assessed the hypothesis that the beta2 sympathomimetic fenoterol influences the production of erythropoietin (EPO) by activation of the renin angiotensin system (RAS), i.e. angiotensin II. METHODS: In an open, parallel, randomized study healthy volunteers received i.v. either placebo (electrolyte solution), fenoterol or fenoterol in combination with an oral dose of the AT1-receptor antagonist losartan. RESULTS: Compared with placebo treatment AUCEPO(0,24 h) was significantly increased after fenoterol application by 48% whereas no increase in the group receiving fenoterol and losartan could be detected. The rise of PRA was statistically significant under fenoterol and fenoterol plus lorsartan. CONCLUSIONS: Stimulation of EPO production during fenoterol infusion appears to be angiotensin II-mediated. Thus, angiotensin II may be considered as one important physiological modulator of EPO production in humans.