IS ERYTHROPOIETIN-INDUCED HYPERTENSION A PHENOMENON DUE TO THE INTRACELLULAR CA++ MOBILIZATION

The authors evaluated the ability of rHuEPO (recombinant human erythro poietin) in performing a vasoactive calcium-mediated action. Forty hea lthy volunteers were evaluated for the muscle blood flow at rest (RBF) and after reactive hyperemia by Xenon 133 clearance. Pre-treatments w ith several calcium antagonists were used. Results. The i.v. infusion of rHuEPO brought about a reduction of the RBF and MBF (maximal blood flow). This reduction was maintained with nifedipine or verapamil. Gal lopamil and ketanserine prevented the reduction of blood flow induced by rHuEPO. Conclusions. The rHuEPO has a vasoconstrictive action in vi vo since gallopamil and ketanserine, drugs able to prevent intracellul ar mobilisation of the Ca++, can block the rHuEPO induced vasoconstric tion. The action exerted by rHuEPO could be due not an increased flow of the Ca++ from the extracellular department but to a mobilisation fr om Ca++ deposits.