Department of Gastroenterological and General Surgery, St. Marianna University Hospital, Kawasaki, Japan.
Biol Pharm Bull. 2010;33(1):77-83. doi: 10.1248/bpb.33.77.
Nitric oxide (NO) and the partial pressure of oxygen (pO(2)) in the liver were simultaneously quantified in rats with partial hepatic ischemia/reperfusion injury (PHIRI). Real-time NO/pO(2) 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. pO(2) 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 (NO(2)+NO(3)). 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 Ca(2+) overloading may effectively minimize organ damage and also have *OH-scavenging activity and the cytoprotective effects of eNOS-derived NO.
在部分肝缺血/再灌注损伤（PHIRI）大鼠中同时定量检测肝脏中一氧化氮（NO）和氧分压（pO2）。进行实时 NO/pO2 监测和超氧化物歧化酶、诱导型一氧化氮合酶（iNOS）和内皮型一氧化氮合酶（eNOS）的免疫组织化学分析，以评估二氢吡啶型钙通道阻滞剂 CV159 对 PHIRI 的保护作用。测量血清高迁移率族蛋白-1（HMGB-1）以评估细胞坏死。此外，我们使用体外/离体电子顺磁共振自旋捕获来评估 CV159 和肝组织的羟基自由基（*OH）清除活性（OHSA）。在缺血期，CV159 治疗组大鼠的 NO 水平明显高于对照组大鼠。再灌注后即刻，NO 水平呈波浪式暂时增加，然后逐渐在治疗组中降低，但在对照组中保持不变。pO2 在治疗组中持续升高。在这些大鼠中，肝组织中 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，并且在治疗组中保留了线粒体和细胞质 OHSA。因此，CV159 介导的细胞内 Ca2+超载抑制可能有效减轻器官损伤，并且具有 *OH 清除活性和 eNOS 衍生的 NO 的细胞保护作用。
