PLASMA ATRIAL-NATRIURETIC PEPTIDE (ANP) AND cGMP LEVELS IN CHILDREN, cGMP AS MARKER FOR THE EFFECT OF ANP ON TARGET TISSUES

The apparent inability of elevated atrial-natriuretic peptide (ANP) levels to cause natriuresis and diuresis in children with heart failure may be related to a reduced response of target organs to ANP. The cellular effects of ANP seem to be mediated by cGMP as the second messenger of ANP. Simultaneous measurement of ANP and cGMP has been shown to be a useful tool to study the cellular response to ANP. Therefore, plasma ANP and cGMP levels were measured by radioimmonoassay in 168 healthy children and in 47 children with congenital cardiac diseases. In healthy children ANP and cGMP plasma levels were measured in the range of 5-109 pg/ml (mean 45.5) and 0.2-2.8 pmol/ml (mean 1.3) respectively. In children with cardiac diseases significantly higher ANP (range 30-980, mean 280 pg/ml) and cGMP levels (range 0.2-6.0, mean 2.8 pmol/ml) were determined. There was a highly significant correlation between the two in children with cardiac diseases (p