C-type natriuretic peptide does not affect plasma and urinary adrenomedullin in man

To investigate whether C-type natriuretic peptide (CNP) at pathophysiologic al plasma levels stimulates the release of adrenomedullin (ADM) in man, six healthy subjects (three men and three women, mean age 35 +/- 3 years, rang e 33-40 years) received an intravenous infusion of synthetic human CNP-22 ( 2 pmol kg(-1) min for 2 h), in a single-blind, placebo-controlled, random o rder, cross-over study, with measurements of the plasma levels of cyclic gu anosine monophosphate (cGMP), ADM, renin and atrial natriuretic peptide (AN P), arterial pressure, heart rate, renal blood flow (para-aminohippurate cl earance), glomerular filtration rate (creatinine clearance), and the urinar y excretion rates of cGMP, ADM and sodium. Infusion of CNP induced increase s in its own levels (from 1.17 +/- 0.11 up to 21.13 +/- 1.41 pmol 1(-1)) wi thout modifying the plasma levels of cGMP, ADM, renin and ANP, the urinary excretion rate of ADM and cGMP, renal haemodynamics and sodium excretion. T hese data indicate that circulating CNP is not involved in the regulation o f ADM release, renal haemodynamics and sodium excretion in man.