Chiş I C, Baltaru D, Dumitrovici A, Coseriu A, Radu B C, Moldovan R, Mureşan A
1 Department of Physiology, "Iuliu Hatieganu" University of Medicine and Pharmacy , Cluj-Napoca, Romania.
2 Department of Internal Medicine, "Constantin Papilian" Military Emergency Hospital , Cluj-Napoca, Romania.
Physiol Int. 2018 Sep 1;105(3):233-246. doi: 10.1556/2060.105.2018.3.23.
Exposure to high altitude in hypobaric hypoxia (HH) is considered to be a physiological oxidative/nitrosative stress. Quercetin (Que) is an effective antioxidant and free radical scavenger against oxidative/nitrosative stress.
The aim of this study was to investigate the cardioprotective effects of Que in animals exposed to intermittent HH (IHH) and therefore exposed to oxidative/nitrosative stress.
Wistar albino male rats were exposed to short-term (2 days) or long-term (4 weeks; 5 days/week) IHH in a hypobaric chamber (5,500 m, 8 h/day, 380 mmHg, 12% O, and 88% N). Half of the animals received natural antioxidant Que (body weight: 30 mg/kg) daily before each IHH exposure and the remaining rats received vehicle (carboxymethylcellulose solution). Control rats were kept under normobaric normoxia (Nx) and treated in a corresponding manner. One day after the last exposure to IHH, we measured the cardiac hypoxia-induced oxidative/nitrosative stress biomarkers: the malondialdehyde (MDA) level and protein carbonyl (PC) content, the activity of some antioxidant enzymes [superoxide dismutase (SOD) and catalase (CAT)], the nitrite plus nitrate (NOx) production, and the inducible nitric oxide synthase (iNOS) protein expression.
Heart tissue MDA and PC levels, NOx level, and iNOS expression of IHH-exposed rats had increased, and SOD and CAT activities had decreased compared with those of the Nx-exposed rats (control groups). MDA, CP, NOx, and iNOS levels had decreased in Que-treated IHH-exposed rats compared with IHH-exposed rats (control groups). However, Que administration increased SOD and CAT activities of the heart tissue in the IHH-exposed rats.
HH exposure increases oxidative/nitrosative stress in heart tissue and Que is an effective cardioprotective agent, which further supports the oxidative cardiac dysfunction induced by hypoxia.
暴露于低氧性低氧环境（HH）中的高海拔环境被认为是一种生理性氧化/亚硝化应激。槲皮素（Que）是一种有效的抗氧化剂和自由基清除剂，可对抗氧化/亚硝化应激。
本研究旨在探讨槲皮素对暴露于间歇性低氧环境（IHH）从而遭受氧化/亚硝化应激的动物的心脏保护作用。
将Wistar白化雄性大鼠置于低压舱（5500米，每天8小时，380毫米汞柱，12%氧气和88%氮气）中暴露于短期（2天）或长期（4周；每周5天）的间歇性低氧环境。一半动物在每次间歇性低氧暴露前每天接受天然抗氧化剂槲皮素（体重：30毫克/千克），其余大鼠接受载体（羧甲基纤维素溶液）。对照大鼠置于常压常氧环境（Nx）下并以相应方式处理。最后一次暴露于间歇性低氧环境一天后，我们测量了心脏缺氧诱导的氧化/亚硝化应激生物标志物：丙二醛（MDA）水平和蛋白质羰基（PC）含量、一些抗氧化酶[超氧化物歧化酶（SOD）和过氧化氢酶（CAT）]的活性、亚硝酸盐加硝酸盐（NOx）的产生以及诱导型一氧化氮合酶（iNOS）蛋白表达。
与暴露于常压常氧环境的大鼠（对照组）相比，暴露于间歇性低氧环境的大鼠心脏组织中MDA和PC水平、NOx水平以及iNOS表达增加，而SOD和CAT活性降低。与暴露于间歇性低氧环境的大鼠（对照组）相比，接受槲皮素治疗的暴露于间歇性低氧环境的大鼠中MDA、CP、NOx和iNOS水平降低。然而，给予槲皮素可增加暴露于间歇性低氧环境的大鼠心脏组织的SOD和CAT活性。
暴露于低氧环境会增加心脏组织中的氧化/亚硝化应激，而槲皮素是一种有效的心脏保护剂，这进一步支持了缺氧诱导的氧化心脏功能障碍。
