Effects of a Calcium-Channel Blocker (CV159) on Hepatic Ischemia/Reperfusion Injury in Rats: Evaluation with Selective NO/pO2 Electrodes and an Electron Paramagnetic Resonance Spin-Trapping Method
作者:Keizo Hataji、Taiji Watanabe、Shigeru Oowada、Masaki Nagaya、Masato Kamibayashi、Eiichi Murakami、Hiroyoshi Kawakami、Atsuko Ishiuchi、Toshio Kumai、Hiroshi Nakano、Shinichi Kobayashi、Takehito Otsubo
DOI:10.1248/bpb.33.77
日期:——
Nitric oxide (NO) and the partial pressure of oxygen (pO2) in the liver were simultaneously quantified in rats with partial hepatic ischemia/reperfusion injury (PHIRI). Real-time NO/pO2 monitoring and immunohistochemical analysis for superoxide dismutase and inducible nitric oxide synthase (iNOS) and endothelial NOS (eNOS) were performed to evaluate the protective effects of a dihydropyridine-type calcium-channel blocker—CV159—on PHIRI. Serum high-mobility-group box-1 (HMGB-1) was measured to assess cellular necrosis. Moreover, we used in vitro/ex vivo electron paramagnetic resonance spin trapping to assess the hydroxyl radical (·OH)-scavenging activity (OHSA) of CV159 and the liver tissue. The NO levels were significantly higher in CV159-treated rats than in control rats throughout the ischemic phase. Immediately after reperfusion, the levels temporarily increased in waves and then gradually decreased in the treated rats but remained constant in the control rats. pO2 was continually higher in the treated rats. In these rats, hepatic eNOS expression increased, whereas iNOS expression decreased. The treated rats exhibited significantly higher cytosolic and mitochondrial concentrations NOx (NO2+NO3). The serum HMGB-1 levels significantly decreased in the treated rats. Moreover, CV159 directly scavenged ·OH and both mitochondrial and cytosolic OHSA were preserved in the treated rats. Thus, CV159-mediated inhibition of intracellular Ca2+ overloading may effectively minimize organ damage and also have ·OH-scavenging activity and the cytoprotective effects of eNOS-derived NO.
在肝局部缺血/再灌注损伤(PHIRI)大鼠中,同时测量了一氧化氮(NO)和肝脏中的氧分压(pO2)。通过实时NO/pO2监测以及超氧化物歧化酶、诱导型一氧化氮合成酶(iNOS)和内皮型一氧化氮合成酶(eNOS)的免疫组织化学分析,评估二氢吡啶类钙通道阻滞剂CV159对PHIRI的保护作用。通过测量血清高迁移率族蛋白1(HMGB-1)来评估细胞坏死。此外,我们使用体外/离体电子顺磁共振自旋捕获技术来评估CV159和肝脏组织对羟自由基(·OH)的清除活性(OHSA)。在整个缺血阶段,CV159治疗组大鼠的NO水平明显高于对照组大鼠。再灌注后,治疗组大鼠的NO水平立即呈波浪状短暂升高,然后逐渐降低,而对照组大鼠的NO水平保持恒定。治疗组大鼠的pO2持续升高。这些大鼠的肝脏eNOS表达增加,而iNOS表达减少。治疗组大鼠的细胞质和线粒体NOx(NO2+NO3)浓度明显升高。治疗组大鼠的血清HMGB-1水平明显降低。此外,CV159直接清除·OH