The aim of this study was to investigate the effect of aging and ovariectomy on various physiological parameters related to inflammation and oxidative stress in livers obtained from old female rats, and the influence of chronic administration of melatonin on these animals. Twenty-four female Wistar rats of 22 months of age were used. Animals were divided into four experimental groups: two intact groups that were untreated or given melatonin (1 mg/kg/day), and two ovariectomized groups that also untreated and treated with melatonin (1 mg/kg/day). After 10 wk of treatment, rats were sacrificed by decapitation, and livers were collected and homogenized. A group of 2-month-old female rats was used as young controls. Protein expression of inducible nitric oxide synthase (iNOS), heme oxygenase-1 (HO-1), IL-6, TNF-alpha and IL-1beta were determined by Western blot analysis. The levels of nitric oxide metabolites (NO(x)), lipid hydroperoxide (LPO), TNF-alpha, IL-1beta, IL-6 and IL-10 were determined. Levels of LPO in the liver homogenates as well as iNOS protein expression and NO(x) levels were increased in old rats as compared with young animals; this effect was more evident in ovariectomized animals. Pro-inflammatory cytokines TNF-alpha, IL-1beta and IL-6 were significantly increased and anti-inflammatory IL-10 decreased during aging and after ovariectomy. Aging also significantly increased the expression of HO-1 protein, and ovariectomized rats showed an additional increase. Administration of melatonin, both to intact and to the ovariectomized animals significantly reduced NO(x), LPO levels and pro-inflammatory cytokines in the liver as compared with untreated rats. Significant rice in IL-10 and reductions in the iNOS, HO-1, IL-6, TNF-alpha and IL-1beta protein expression were also found in rats treated with melatonin. Oxidative stress and inflammation induced during aging in the liver are more marked in castrated than in intact females. Administration of melatonin reduces both these situations.

中文翻译：

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褪黑素能够防止cast割的雌性老年大鼠的肝脏受到氧化和促炎性损害。

这项研究的目的是研究衰老和卵巢切除术对老年雌性大鼠肝脏中与炎症和氧化应激有关的各种生理参数的影响，以及长期服用褪黑激素对这些动物的影响。使用24只22个月大的雌性Wistar大鼠。将动物分为四个实验组：两个未治疗或给予褪黑激素的完整组（1 mg / kg /天），和两个也未治疗并用褪黑激素治疗的卵巢切除组（1 mg / kg /天）。治疗10周后，将大鼠断头处死，收集肝脏并匀浆。一组2个月大的雌性大鼠用作年轻对照。诱导型一氧化氮合酶（iNOS），血红素加氧酶-1（HO-1），IL-6，通过蛋白质印迹分析确定TNF-α和IL-1β。测定一氧化氮代谢产物（NO（x）），脂质氢过氧化物（LPO），TNF-α，IL-1β，IL-6和IL-10的水平。与年幼动物相比，老年大鼠肝脏匀浆中的LPO水平以及iNOS蛋白表达和NO（x）水平增加；这种作用在去卵巢动物中更为明显。在衰老过程中和卵巢切除术后，促炎细胞因子TNF-α，IL-1β和IL-6显着增加，抗炎IL-10降低。衰老还显着增加了HO-1蛋白的表达，而去卵巢的大鼠显示出更多的增加。完整和去卵巢的动物均服用褪黑激素可显着降低NO（x），与未治疗的大鼠相比，肝脏中的LPO水平和促炎性细胞因子。在褪黑素治疗的大鼠中还发现了水稻中IL-10的显着升高以及iNOS，HO-1，IL-6，TNF-α和IL-1beta蛋白表达的降低。与完整的女性相比，cast割的肝脏中氧化应激和炎症反应更为明显。褪黑激素的给药减少了这两种情况。