Alrefaie Zienab, Alhayani Abdulmone'em
Physiology Department, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia.
Anatomy Department, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia.
Behav Brain Res. 2015;287:156-62. doi: 10.1016/j.bbr.2015.03.050. Epub 2015 Mar 30.
Complications of diabetes mellitus include cognitive impairments and functional changes in the brain. The present study aimed to investigate the possible beneficial effect of vitamin D3 on episodic memory and cholinergic transmission in the prefrontal cortex of streptozotocin-induced diabetic rats. Thirty male Wistar rats (150-200 g) were included into control, diabetic and diabetic supplemented with vitamin D3 groups. Diabetes was induced by single intraperitoneal injection of streptozotocin 45 mg/kg in citrate buffer. Vitamin D3 was administered orally in a dose of 500 IU/kg/day in corn oil for 10 weeks. Then rats were subjected to novel object recognition test to examine for episodic memory. Animals were sacrificed under diethyl ether anesthesia and prefrontal cortices were dissected to measure the activity of choline acetyl transferase (CAT) and acetyle choline esterase (ACE) enzymes to assess for cholinergic transmission. Diabetic rats spent significantly less time exploring the novel object compared to control animals. Vitamin D3 significantly attenuated the diabetes-induced impairment so that animals again spent significantly more time exploring the novel object. The CAT activity was significantly decreased in diabetic animals while the ACE activity was significantly increased compared to control non-diabetic animals. Diabetes-induced alterations in enzyme activity in the prefrontal cortex were mitigated by vitamin D3 supplementation. The present findings demonstrate the potential effect of vitamin D3 supplementation on cognitive function in diabetic animals. It is possible that this effect is mediated through enhancing the prefrontal cortex cholinergic transmission.
糖尿病的并发症包括认知障碍和大脑功能变化。本研究旨在探讨维生素D3对链脲佐菌素诱导的糖尿病大鼠前额叶皮质情景记忆和胆碱能传递可能产生的有益作用。将30只雄性Wistar大鼠（150 - 200克）分为对照组、糖尿病组和补充维生素D3的糖尿病组。通过在柠檬酸盐缓冲液中腹腔注射45毫克/千克链脲佐菌素诱导糖尿病。维生素D3以500国际单位/千克/天的剂量口服溶于玉米油中，持续10周。然后对大鼠进行新物体识别测试以检查情景记忆。在乙醚麻醉下处死动物，解剖前额叶皮质以测量胆碱乙酰转移酶（CAT）和乙酰胆碱酯酶（ACE）的活性，以评估胆碱能传递。与对照动物相比，糖尿病大鼠探索新物体的时间明显减少。维生素D3显著减轻了糖尿病诱导的损伤，使动物再次花费显著更多的时间探索新物体。与对照非糖尿病动物相比，糖尿病动物的CAT活性显著降低，而ACE活性显著增加。补充维生素D3减轻了糖尿病诱导的前额叶皮质酶活性变化。本研究结果证明了补充维生素D3对糖尿病动物认知功能的潜在作用。这种作用可能是通过增强前额叶皮质胆碱能传递介导的。
