Hejazian Seyed Hassan, Karimi Sareh, Hosseini Mahmoud, Mousavi Seyed Mojtaba, Soukhtanloo Mohammad
Department of Physiology, Shahid Sadoghi University of Medical Sciences, Yazd, Iran.
Neurocognitive Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Adv Biomed Res. 2016 Jul 29;5:123. doi: 10.4103/2277-9175.186981. eCollection 2016.
Regarding the anti-oxidative effects on the central nervous system, the possible protection against brain tissues oxidative damage as a possible mechanism for improving effects of low doses of estradiol on scopolamine-induced learning and memory impairments was investigated in ovariectomized (OVX) rats.
The OVX rats treated by (1) vehicle, (2) scopolamine, and (3-4) scopolamine plus estradiol (20 or 20 or 60 μg/kg). Estradiol was administered (20 or 60 μg/kg, intraperitoneally) daily for 6 weeks after ovariectomy. The rats were examined for learning and memory using passive avoidance test. Scopolamine (2 mg/kg) was injected 30 min after training in the test. The brains were then removed to determine malondialdehyde (MDA) and thiol contents.
Scopolamine shortened the time latency to enter the dark compartment in (P < 0.01). Compared to scopolamine, pretreatment by both doses of estradiol prolonged the latency to enter the dark compartment (P < 0.01). The brain tissues MDA concentration as an index of lipid peroxidation was decreased (P < 0.05). Pretreatment by estradiol lowered the concentration of MDA, while it increased thiol content compared to scopolamine (P < 0.05 and P < 0.01).
These results allow us to suggest a protection against brain tissues oxidative damage as a possible mechanism for improving effects of low doses of estradiol on scopolamine-induced learning and memory impairments in OVX rats.
关于对中枢神经系统的抗氧化作用，研究了在去卵巢（OVX）大鼠中，低剂量雌二醇改善东莨菪碱诱导的学习和记忆障碍的可能机制，即对脑组织氧化损伤的潜在保护作用。
将OVX大鼠分为四组，分别给予（1）溶剂、（2）东莨菪碱、（3 - 4）东莨菪碱加雌二醇（20或20或60μg/kg）。去卵巢后每天腹腔注射雌二醇（20或60μg/kg），持续6周。采用被动回避试验检测大鼠的学习和记忆能力。在试验训练后30分钟注射东莨菪碱（2mg/kg）。然后取出大脑，测定丙二醛（MDA）和硫醇含量。
东莨菪碱缩短了进入暗室的潜伏期（P < 0.01）。与东莨菪碱组相比，两种剂量的雌二醇预处理均延长了进入暗室的潜伏期（P < 0.01）。作为脂质过氧化指标的脑组织MDA浓度降低（P < 0.05）。与东莨菪碱相比，雌二醇预处理降低了MDA浓度，同时增加了硫醇含量（P < 0.05和P < 0.01）。
这些结果表明，对脑组织氧化损伤的保护作用可能是低剂量雌二醇改善OVX大鼠中东莨菪碱诱导的学习和记忆障碍的一种机制。
