PT - JOURNAL ARTICLE AU - Hannu Kankaanranta AU - Xianzhi Zhang AU - Ritva Tumelius AU - Minna Ruotsalainen AU - Heimo Haikala AU - Erkki Nissinen AU - Eeva Moilanen TI - Antieosinophilic Activity of Simendans AID - 10.1124/jpet.107.124057 DP - 2007 Oct 01 TA - Journal of Pharmacology and Experimental Therapeutics PG - 31--38 VI - 323 IP - 1 4099 - http://jpet.aspetjournals.org/content/323/1/31.short 4100 - http://jpet.aspetjournals.org/content/323/1/31.full SO - J Pharmacol Exp Ther2007 Oct 01; 323 AB - Simendans are novel agents used in the treatment of decompensated heart failure. They sensitize troponin C to calcium and open ATP-sensitive potassium channels and have been shown to reduce cardiac myocyte apoptosis. The aim of the present study was to evaluate whether simendans reduce pulmonary eosinophilia and regulate eosinophil apoptosis. Bronchoalveolar lavage (BAL) eosinophilia was evaluated in ovalbumin-sensitized mice. Effects of simendans on apoptosis in isolated human eosinophils were assessed by relative DNA fragmentation assay, annexin V-binding, and morphological analysis. Dextrosimendan [(+)-[[4-(1,4,5,6-tetrahydro-4-methyl-6-oxo-3-pyridazinyl)phenyl)hydrazono]propanedinitrile] reduced ovalbumin-induced BAL-eosinophilia in sensitized mice. Levosimendan [(–)-[[4-(1,4,5,6-tetrahydro-4-methyl-6-oxo-3-pyridazinyl)phenyl]hydrazono]propanedinitrile] and dextrosimendan reversed interleukin (IL)-5-afforded survival of human eosinophils by inducing apoptosis in vitro. Even high concentrations of IL-5 were not able to overcome the effect of dextrosimendan. Dextrosimendan further enhanced spontaneous apoptosis as well as that induced by CD95 ligation, without inducing primary necrosis. Dextrosimendan-induced DNA fragmentation was shown to be dependent on caspase and c-Jun NH2-terminal kinase activation, whereas extracellular signal-regulated kinase, p38 mitogen-activated kinase, and ATP-sensitive potassium channels seemed to play no role in its actions. Taken together, our results show that simendans possess antieosinophilic activity and may be useful for the treatment of eosinophilic inflammation. The American Society for Pharmacology and Experimental Therapeutics