Atrial natriuretic peptide in relative polycythemia and polycythemia vera.

Atrial natriuretic peptide (ANP) levels have been tested in patients with chronic relative polycythemia (RP), polycythemia vera, and in healthy subjects in order to find a possible underlying pathophysiological mechanism for relative polycythemia. No difference in statistical significance has been found between the mean atrial natriuretic peptide levels of the polycythemic patients and the control group. It is suggested that ANP probably plays no significant role in the contraction of plasma volume observed in normotensive patients with RP.