【作者】 尹华祺；

【导师】 周定刚；

【作者基本信息】 四川农业大学 ， 基础兽医学， 2009， 硕士

【摘要】 目的:探讨褪黑素(melatonin,MT)对热应激小鼠的免疫功能、抗氧化功能的影响及可能的机制。方法:将140只6-8周龄的清洁级昆明小鼠随机分为空白对照组(注射生理盐水)和MT低、中、高剂量(分别皮下注射MT 5 mg/kg.wt、10mg/kg.wt、20mg/kg.wt)试验组,共四组。每组35只小鼠,其中每小组各有5只作为常温对照,其余30只为热应激组。除常温组外均进行热应激处理,即每次将试验小鼠置于37℃生化培养箱1h,连续7d。在末次热应激处理后的0、2、4、8、12、24h六个时间点,分别将其处死(每个时间点处死5只小鼠),摘除眼球取血、测量并比较不同情况下各组小鼠的应激指示器官(肾上腺、脾、胸腺)重量、血液中免疫相关血细胞(白细胞、淋巴细胞、粒细胞、中值细胞、)的数量、血浆的抗氧化指标(T-AOC、SOD、GSH-Px、MDA)以及应激指示器官的病理变化。数据用SPSS软件分析。结果:1.褪黑素能缓解热应激小鼠的体重下降、体温升高;2.褪黑素可缓解热应激导致的小鼠胸腺和脾脏急性萎缩及肾上腺肥大;3.热应激处理后,与免疫相关的血细胞(白细胞、淋巴细胞、单核细胞、粒细胞)数量明显减少,注射高、中剂量的褪黑素能增加其数量;4.经热应激处理后,小鼠抗氧化酶(SOD、GSH-Px)活性和总抗氧化能力(T-AOC)下降,MDA的含量升高,而褪黑素能有效的清除自由基,提高抗氧化酶的活性;5.热应激小鼠的应激指示器官脾和肾上腺发生病变,而褪黑素组的病变不明显。结论:1.在热应激处理后,小鼠的免疫功能和抗氧化性能受到明显损害;2.褪黑素对热应激损伤小鼠的免疫功能起保护作用,可提高其抗氧化能力;3.褪黑素能减轻热应激导致的小鼠应激指示器官(脾、肾上腺)的病变。更多还原

【Abstract】 Objective: to study the effect of melatonin on mouse immunity、antioxidation and its possible mechanisms. Method: 140 mice (Km, female, 6-8 weeks of age) were divided into 4 groups. Group 1 was treated with physiological saline (for control) ;group 2-4 was given melatonin in 5 mg/kg .wt,10mg/kg.wt,20mg/kg.wt concentration respectively. In each group, some mice were killed at time of 0, 2,4,8,12,24 hours after the last time heat stress (37°C,1 hour) treatment ,the others at room temperature were also killed . weight of stress marker organs ( Adrenal Glands, Spleen,thymus gland ) ,concentration of immunocyte(WBC,LYM,MID,GRAN) in blood, antioxidation index(T-AOC、SOD、GSH-Px、MDA),pathological change of stress marker organs were measured. Data were processed with SPSS soft ware. Results: 1. melatonin could remit the weight decrease and rectal temperature rise caused by heat stress;2. melatonin could relieve thymus and spleen’s acute atrophy and adrenal gland’s hypertrophy caused by heat stress;3. melatonin with middle and high dose could raise the immune related blood cells amount ;4. the activity of the antioxidase(SOD、GSH-Px) and tatal antioxygen capability declined while contents of MDA rised after heat stress, melatonin could aliminate free radical effectively and elevated the activity of the antioxidase;5. the stress indicating organs presented pathological change after heat stress,the melatonin groups were not obvious .Conclusions:1. The immunity and antioxidation of the mice is obviously damaged after heat stress;2. melatonin could protect the immunity and antioxygen capability of mice under heat stress;3. melatonin could mitigate pathological change coused by heat stress.更多还原