Cicletanine does not affect plasma atrial natriuretic peptide concentration in healthy subjects

The effect of 50 and 150 mg cicletanine, a new vasodilator antihypertensive, on plasma atrial natriuretic peptide (ANP), cyclic GMP and antidiuretic hormone has been investigated at rest and during standardized exercise, in a double blind cross over study in healthy subjects. Exercise significantly increased in plasma ANP, cyclic GMP and antidiuretic hormone concentrations, and cicletanine did not affect any of them either at rest or during exercise. Since the alpha-1 adrenoceptor blocker prazosine decreases, beta-adrenoceptor blockers increase and the vasodilator cicletanine does not alter the plasma ANP response to exercise, it is suggested that adrenergic receptors may be directly involved in the regulation of ANP secretion.