Nicorandil Attenuates Monocrotaline-Induced Vascular Endothelial Damage and Pulmonary Arterial Hypertension

作者：Sahara Makoto^*; Sata Masataka; Morita Toshihiro; Hirata Yasunobu; Nagai Ryozo

来源：PLos One, 2012, 7(3): e33367.

DOI：10.1371/journal.pone.0033367

Background: An antianginal K-ATP channel opener nicorandil has various beneficial effects on cardiovascular systems; however, its effects on pulmonary vasculature under pulmonary arterial hypertension (PAH) have not yet been elucidated. Therefore, we attempted to determine whether nicorandil can attenuate monocrotaline (MCT)-induced PAH in rats. %26lt;br%26gt;Materials and Methods: Sprague-Dawley rats injected intraperitoneally with 60 mg/kg MCT were randomized to receive either vehicle; nicorandil (5.0 mg.kg(-1).day(-1)) alone; or nicorandil as well as either a K-ATP channel blocker glibenclamide or a nitric oxide synthase (NOS) inhibitor N-infinity-nitro-L-arginine methyl ester (L-NAME), from immediately or 21 days after MCT injection. Four or five weeks later, right ventricular systolic pressure (RVSP) was measured, and lung tissue was harvested. Also, we evaluated the nicorandil-induced anti-apoptotic effects and activation status of several molecules in cell survival signaling pathway in vitro using human umbilical vein endothelial cells (HUVECs). %26lt;br%26gt;Results: Four weeks after MCT injection, RVSP was significantly increased in the vehicle-treated group (51.0 +/- 4.7 mm Hg), whereas it was attenuated by nicorandil treatment (33.2 +/- 3.9 mm Hg; P%26lt;0.01). Nicorandil protected pulmonary endothelium from the MCT-induced thromboemboli formation and induction of apoptosis, accompanied with both upregulation of endothelial NOS (eNOS) expression and downregulation of cleaved caspase-3 expression. Late treatment with nicorandil for the established PAH was also effective in suppressing the additional progression of PAH. These beneficial effects of nicorandil were blocked similarly by glibenclamide and L-NAME. Next, HUVECs were incubated in serum-free medium and then exhibited apoptotic morphology, while these changes were significantly attenuated by nicorandil administration. Nicorandil activated the phosphatidylinositol 3-kinase (PI3K)/Akt and extracellular signal-regulated kinase (ERK) pathways in HUVECs, accompanied with the upregulation of both eNOS and Bcl-2 expression. %26lt;br%26gt;Conclusions: Nicorandil attenuated MCT-induced vascular endothelial damage and PAH through production of eNOS and anti-apoptotic factors, suggesting that nicorandil might have a promising therapeutic potential for PAH.

• 出版日期2012-3-30