Levosimendan induces NO production through p38 MAPK, ERK and Akt in porcine coronary endothelial cells: role for mitochondrial K_ATPchannel

Abstract

Background and purpose: Levosimendan acts as a vasodilator through the opening of ATP-sensitive K + channels (KATP) channels. Moreover, the coronary vasodilatation caused by levosimendan in anaesthetized pigs has recently been found to be abolished by the nitric oxide synthase (NOS) inhibitor N w -nitro-L-arginine methyl ester, indicating that nitric oxide (NO) has a role in the vascular effects of levosimendan. However, the intracellular pathway leading to NO production caused by levosimendan has not yet been investigated. Thus, the purpose of the present study was to examine the effects of levosimendan on NO production and to evaluate the intracellular signalling pathway involved. Experimental approach: In porcine coronary endothelial cells (CEC), the release of NO in response to levosimendan was examined in the presence and absence of N w -nitro-L-arginine methyl ester, an adenylyl cyclase inhibitor, KATP channel agonists and antagonists, and inhibitors of intracellular protein kinases. In addition, the role of Akt, ERK, p38 and eNOS was investigated through Western blot analysis. Key results: Levosimendan caused a concentration-dependent and K + -related increase of NO production. This effect was amplified by the mitochondrial KATP channel agonist, but not by the selective plasma membrane KATP channel agonist. The response of CEC to levosimendan was prevented by the KATP channel blockers, the adenylyl cyclase inhibitor and the Akt, ERK, p38 inhibitors. Western blot analysis showed that phosphorylation of the above kinases lead to eNOS activation. Conclusions and implications:In CEC levosimendan induced eNOS-dependent NO production through Akt, ERK and p38. This intracellular pathway is associated with the opening of mitochondrial KATP channels and involves cAMP.

Levosimendan improves cardiac function and survival in rats with angiotensin II-induced hypertensive heart failure

“…In very good agreement with our data, other investigators found that levosimendan and its metabolite OR-1896 elicit a substantial vasodilation and an increase in nitric oxide production in the coronary and skeletal muscle arterioles by activating voltage-sensitive, calcium-activated and ATPsensitive potassium channels. [29][30][31] This response to levosimendan could partly be prevented by the K(ATP) channel blockers. [29][30][31] Moreover, in an in vivo rat model of coronary ischemia-reperfusion, levosimendan decreased infarct size markedly through the K(ATP) channel-dependent pathway, whereas the PDE-III inhibitor enoximone did not cause any infarct size reduction.…”

“…[29][30][31] This response to levosimendan could partly be prevented by the K(ATP) channel blockers. [29][30][31] Moreover, in an in vivo rat model of coronary ischemia-reperfusion, levosimendan decreased infarct size markedly through the K(ATP) channel-dependent pathway, whereas the PDE-III inhibitor enoximone did not cause any infarct size reduction. 32 Thus, the role of PDE inhibition as a mediator of the beneficial effects of levosimendan found in this study remains unclear.…”

Szabad gyökök és a máj ischaemiás-reperfúziós károsodása

“…A -kardiológiai alkalmazása kapcsán inodilatátor hatású szerként ismert -levosimendan a klasszikus kémi-ai kondicionálószerek közé tartozik. Fő hatása -RISKaktivátor [28] és NO-felszabadító [29] hatása melletta mitokondriális K + ATP -csatorna nyitása, amely a mitokondrium integritásának, illetve a terminális oxidá-ció pontos működésének megőrzéséhez vezet [30]. Ebbéli antiischaemiás, gyulladásgátló hatása saját kísér-letünkben is igazolódott, ahol a "korai" (1-3 órás), illetve "késői" (24 órás) preoperatív előkezelés a máj I-R károsodásának csökkenéséhez vezetett.…”

Calcium handling in porcine coronary endothelial cells by gastrin-17

“…Experiments were performed in primary culture cells, PCAEC, which were isolated from coronary arteries of anaesthetized pigs, as described previously (Grossini et al 2009). The cells were plated into 0.1% gelatincoated culture dish by endothelial growth media-2 (EGM-2; EGM-2 BulletKit (CC-3124); Lonza, Inc., Basel, Switzerland) with the addition of human epidermal growth factor, hydrocortisone, gentamycin-amphotericin-B 1000, 2% foetal bovine serum (FBS), vascular endothelial growth factor, human fibroblast growth factor-basic, recombinant analogue insulin-like growth factor 1-human, ascorbic acid, heparin (Lonza) and 1% penicillin-streptomycin-glutamine (Sigma-Aldrich) and maintained in incubator at 37 8C and 5% CO 2 .…”