The present invention relates to a nitrogen-containing heterocyclic compound exhibiting an inhibitory activity against cGMP-PDE. The compound represented by the formula (I) or a pharmacologically acceptable salt thereof: ##STR1## wherein R.sup.1 represents a group represented by the formula: --NR.sup.4 R.sup.5 (wherein R.sup.4 and R.sup.5 each represent hydrogen, lower alkyl or the like) or the like; R.sup.2 represents a group represented by the formula: ##STR2## (wherein R.sup.8 represents a carboxyl group which may be protected, or the like) or the like; and R.sup.3 represents a group represented by the formula: ##STR3## (wherein R.sup.6 and R.sup.7 each represent hydrogen, lower alkyl or the like) or the like.