Abstract: An agent for therapeutic and/or prophylactic treatment of heart failure or arrhythmia in diabetic ischemic heart disease, which comprises as an active ingredient an aminobenzenesulfonic acid derivative represented by the following general formula (I): (wherein R1 represents, for example, hydrogen atom; R2 represents, for example, hydrogen atom; and n represents an integer of from 1 to 4) or a salt thereof, or a hydrate thereof or a solvate thereof, and an agent for therapeutic and/or prophylactic treatment of diabetic ischemic heart disease wherein said agent improves a cardiac dysfunction in diabetic ischemic heart disease.

Abstract: A medicament for treating or preventing diastolic dysfunction, comprising 2-(1-piperazinyl)-5-methylbenzenesulfonic acid derivative or its salt, or hydrate or solvate thereof as an active ingredient.

Abstract: A medicament for treating or preventing diastolic dysfunction, comprising 2-(1-piperazinyl)-5-methylbenzenesulfonic acid derivative or its salt, or hydrate or solvate thereof as an active ingredient.

Abstract: There are provided novel pyridazinone derivatives having the general formula (I): ##STR1## wherein A represents 5- or 6-membered heterocyclic ring having 1-3 nitrogen atoms, which may be substituted by at least one member selected from the group consisting of C.sub.1-5 alkyl, cyano, hydroxyl, C.sub.1-5 alkoxyl, amino, C.sub.1-5 alkylamino, C.sub.2-6 dialkylamino, C.sub.2-5 acylamino, carboxyl, C.sub.2-5 alkoxycarbonyl and carbamoyl, and R.sup.1 and R.sup.2 independently represent hydrogen atom or C.sub.1-5 alkyl or R.sup.1 and R.sup.2 may form together C.sub.1-5 alkylene, and salts thereof.

Abstract: Pyridazinone derivatives represented by the following general formula (I): ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 represent a hydrogen atom, hydroxy group or alkoxy group of not more than 5 carbon atoms, or two of R.sub.1, R.sub.2 and R.sub.3 may be combined together to form a group of --O--CH.sub.2 --O-- or --O--CH.sub.2 --CH.sub.2 --O--, R.sub.4 represents an alkyl group, n represents an integer of 0 to 4 and the dotted line represents a single or double bond, or salts thereof.

Abstract: There are provided novel pyridazinone derivatives having the general formula (I): ##STR1## wherein A represents 5- or 6-membered heterocyclic ring having 1-3 nitrogen atoms, which may be substituted by at least one member selected from the group consisting of C.sub.1-5 alkyl, cyano, hydroxyl, C.sub.1-5 alkoxy, amino, C.sub.1-5 alkylamino, C.sub.2-6 dialkylamino, C.sub.2-5 acylamino, carboxyl, C.sub.2-5 alkoxycarbonyl and carbamoyl, and R.sup.1 and R.sup.2 independently represent hydrogen atom or C.sub.1-5 alkyl or R.sup.1 and R.sup.2 may form together C.sub.1-5 alkylene, and salts thereof.