Abstract: A fused pyridazine compound represented by the following general formula (I) or a pharmacologically acceptable salt thereof which exhibits an inhibitory activity against cyclic GMP phosphodiesterase (hereinafter referred to as “cGMP-PDE”). The compounds are useful as preventive and therapeutic agents for diseases for which a cGMP-PDE inhibiting action is efficacious, for example, ischemic heart diseases such as angina pectoris, myocardial infarct and chronic and acute cardiac failure, pulmonary hypertension, arteriosclerosis and bronchial asthma.

Abstract: A fused pyridazine compound represented by the following general formula (I) or a pharmacologically acceptable salt thereof which exhibits an inhibitory activity against cyclic GMP phosphodiesterase (hereinafter referred to as "cGMP-PDE").The compounds are useful as preventive and therapeutic agents for diseases for which a cGMP-PDE inhibiting action is efficacious, for example, ischemic heart diseases such as angina pectoris, myocardial infarct and chronic and acute cardiac failure, pulmonary hypertension, arteriosclerosis and bronchial asthma.

Abstract: 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.

Abstract: It relates to a quinazoline compound useful as a medicine exhibiting an inhibitory action on calmodulin-dependent cGMP-PDE.A quinazoline compound represented by the general formula (I) or a pharmacologically acceptable salt thereof: ##STR1## (wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 may be the same or different from each other and each represents a hydrogen atom, a lower alkyl group or the like; and R.sup.6 and R.sup.7 may be the same or different from each other and each represents a hydrogen atom, a carboxyl alkyl group or the like).