Kireev R A, Tresguerres A C F, Castillo C, Salazar V, Ariznavarreta C, Vara E, Tresguerres J A F
Department Biochemistry and Biophysics, Saratov State University, Saratov, Russia.
J Pineal Res. 2007 Jan;42(1):64-70. doi: 10.1111/j.1600-079X.2006.00385.x.
Aging is accompanied by changes in the morphology and physiology of organs and tissues, such as the liver. This process might be due to the accumulation of oxidative damage induced by reactive oxygen (ROS) and reactive nitrogen species (RNS). Hepatocytes are very rich in mitochondria and have a high respiratory rate, so they are exposed to large amounts of ROS and permanent oxidative stress. Twenty-four male Wistar rats of 22 months of age were divided into three groups. One group remained untreated and acted as the control group. The second was treated with growth hormone (GH) (2 mg/kg/d sc) and the third was submitted to treatment wit 1 mg/kg/d of melatonin in the drinking water. A group of 2-months-old male rats was used as young controls. After 10 wk of treatment the rats were killed by decapitation, and the liver was dissected and homogenized. Mitochondrial, cytosolic and microsomal fractions were obtained and cytochrome C, glutathione peroxidase, s-transferase and nitric oxide (NO) were measured. Aging induced a significant increase in mitochondrial nitric oxide. An increase in cytochrome C in the cytosolic fraction and a reduction in the mitochondrial fraction with age was also observed. Both GH and melatonin treatments significantly reduced the enhanced measures and increased the reduced values. A reduction in glutathione peroxidase and glutathione S-transferase was found in old control rats when compared with the group of young animals. Treatment for 2.5 months of old rats with GH and melatonin were able to increase the enzymes reaching values similar to those found in young animals. In conclusion, GH and melatonin treatment seems to have beneficial effects against age-induced damage in the liver.
衰老伴随着器官和组织（如肝脏）形态和生理的变化。这个过程可能是由于活性氧（ROS）和活性氮（RNS）诱导的氧化损伤积累所致。肝细胞富含线粒体且呼吸速率高，因此它们暴露于大量的ROS和持续的氧化应激中。将24只22月龄的雄性Wistar大鼠分为三组。一组不进行处理作为对照组。第二组用生长激素（GH）（2毫克/千克/天，皮下注射）处理，第三组在饮用水中加入1毫克/千克/天的褪黑素进行处理。一组2月龄的雄性大鼠用作年轻对照组。处理10周后，大鼠断头处死，解剖肝脏并匀浆。获得线粒体、胞质和微粒体部分，并测量细胞色素C、谷胱甘肽过氧化物酶、s -转移酶和一氧化氮（NO）。衰老导致线粒体一氧化氮显著增加。随着年龄增长，胞质部分细胞色素C增加，线粒体部分细胞色素C减少也被观察到。GH和褪黑素处理均显著降低了升高的指标并提高了降低的值。与年轻动物组相比，老年对照大鼠的谷胱甘肽过氧化物酶和谷胱甘肽S -转移酶减少。用GH和褪黑素对老年大鼠进行2.5个月的处理能够增加这些酶，使其达到与年轻动物相似的值。总之，GH和褪黑素处理似乎对肝脏衰老诱导的损伤具有有益作用。
