Cytoprotective Effect of 3-[2-[4-(3-Chloro-2-methylphenyl)-1-piperazinyl]ethyl]-5,6-dimethoxy-1-(4-imidazolylmethyl)-1H-indazole Dihydrochloride 3.5 Hydrate (DY-9760e) Against Ischemia/Reperfusion-Induced Injury in Rat Heart Involves Inhibition of Fodrin Breakdown and Protein Tyrosine Nitration

Abstract

Abstract. We here assessed the effects of 3-[2-[4-(3-chloro-2-methylphenyl)-1-piperazinyl] ethyl]-5,6-dimethoxy-1-(4-imidazolylmethyl)-1H-indazole dihydrochloride 3.5 hydrate (DY9760e), a novel calmodulin antagonist, on infarct size in the rat heart subjected to ischemia / reperfusion. Rats were subjected to a 30-min coronary occlusion followed by a 24-h reperfusion. DY-9760e was intravenously infused for 20 min, starting at 20 min after coronary occlusion. Treatment with DY-9760e (10 mg / kg) significantly reduced the infarct size in the risk area assessed by Evans Blue / TTC (triphenyltetrazolium chloride) staining. DY-9760e treatment also ameliorated contractile dysfunction of the left ventricle 72 h after reperfusion. DY-9760e significantly inhibited fodrin breakdown and caspase-3 activation. The inhibitory effect of DY9760e on the fodrin breakdown was prominent in the rim rather than in the center of the risk area. DY-9760e also blocked protein tyrosine nitration associated with infarction. These results suggest that the cardioprotective effect of DY-9760e involved inhibition of calpain / caspase activation and protein tyrosine nitration.

Ultrafine particulate matter exposure augments ischemia-reperfusion injury in mice

“…After the 2-h reperfusion period, the LAD was religated at the original point of occlusion. The myocardium at risk was delineated by infusing 1% Evans blue solution through the aorta as adapted from Hashimoto et al (21). The right ventricle was removed, the entire LV was weighed, and the unstained LV region was removed and weighed to determine the percentage of the total LV tissue at risk for ischemia (14).…”

Inhibition of Dystrophin Breakdown and Endothelial Nitric-Oxide Synthase Uncoupling Accounts for Cytoprotection by 3-[2-[4-(3-Chloro-2-methylphenyl)-1-piperazinyl]ethyl]-5,6-dimethoxy-1-(4-imidazolylmethyl)-1H-indazole Dihydrochloride 3.5 Hydrate (DY-9760e) in Left Ventricular Hypertrophied Mice

“…In addition, DY-9760e significantly inhibits activation of Ca 2ϩ /CaM-dependent nitric-oxide synthase after brain and heart ischemia (Hashiguchi et al, 2004;Hashimoto et al, 2005;Han et al, 2006). The antihypertrophic effect of DY9760e is mediated primarily by inhibition of Ca 2ϩ /CaM-dependent activation of CaMKII␦ in cardiomyocytes (Lu et al, 2009b).…”

“…Calpain activation followed by dystrophin breakdown leads to myocardial injury. Indeed, breakdown of dystrophin and spectrin correlates with myocardial injury after cardiac ischemia (Armstrong et al, 2001;Hashimoto et al, 2005). In cardiac ischemia, calpain activity mediates impaired Na ϩ /K ϩ -ATPase activity with concomitant spectrin breakdown (Inserte et al, 2005).…”

“…Blots were then stained with 0.1% Ponceau S solution to visualize protein bands and confirm equal protein loading among groups. After blocking in 5% nonfat milk, blots were incubated overnight at 4°C with antibodies against dystrophin (mouse monoclonal antibody, 1:1000; Millipore Bioscience Research Reagents, Temecula, CA), spectrin, caveolin-3, eNOS, and nitrotyrosine (rabbit polyclonal antibody, 1:500; Hashimoto et al, 2005;Lu et al, 2009a). Immunoreactive proteins on membranes were visualized with an enhanced chemiluminescence (ECL) detection system (GE Healthcare, Little Chalfont, Buckinghamshire, UK).…”

“…We have found that the novel calmodulin antagonist DY9760e can protect the heart from ischemic/reperfusion injury (Hashimoto et al, 2005) and that its active metabolite DY-9836 prevents phenylephrine-induced injury to cultured cardiomyocytes (Lu et al, 2009a). It is more important that DY-9836 treatment totally inhibited aberrant NO production and superoxide generation by uncoupled eNOS after phenylephrine treatment of these cells (Lu et al, 2009a).…”