| 摘要: |
| 目的：观察抗氧化剂褪黑素对糖尿病大鼠氧化应激指标及下丘脑垂体肾上腺轴功能的影响，探讨褪黑素对糖尿病大鼠保护作用的可能机制。方法：雄性SD大鼠随机分为正常对照组(n=6)、糖尿病组(DM,n=7)、糖尿病褪黑素治疗1组(DM+Mel1,n=6)和糖尿病褪黑素治疗2组(DM+Mel2,n=6)。腹腔注射链脲佐菌素(65 mg/kg)制备糖尿病大鼠模型，DM+Mel1组给予10 mg/kg褪黑素灌胃，DM+Mel2组给予0.2 mg/kg褪黑素灌胃,正常对照组和DM组每天灌胃等体积的2%乙醇溶液。12周后检测各组大鼠血糖、体质量、双侧肾上腺质量/体质量值，比色法检测血丙二醇（MDA）含量，酶学法检测血总胆固醇（TC）、三酰甘油（TG）含量，放射免疫法检测血促肾上腺皮质激素释放激素（CRH）、促肾上腺皮质激素（ACTH）、皮质酮（CORT）含量。结果：与正常对照组相比，DM组大鼠血糖水平、双侧肾上腺质量/体质量、MDA、TC、TG 、CRH、ACTH、CORT水平显著升高(P<0.01)，体质量明显减轻(P<0.01)；与DM组相比，DM+Mel1组和DM+Mel2组大鼠血糖、双侧肾上腺质量/体质量、MDA、TC、TG显著降低(P<0.01 或P<0.05)，体质量明显升高(P<0.01或P<0.05)，DM+Mel1组大鼠血CRH、ACTH、CORT水平显著降低(P<0.01)，DM+Mel2组大鼠血CORT水平显著降低(P<0.05)，DM+Mel2组大鼠血CRH、ACTH水平没有明显改变。结论：褪黑素可以降低糖尿病大鼠氧化应激水平，改善糖、脂肪代谢紊乱，抑制下丘脑垂体肾上腺轴功能，对实验性糖尿病具有保护作用。 |
| 关键词: 褪黑激素 糖尿病，实验性 下丘脑-垂体-肾上腺轴 |
| DOI：10.3724/SP.J.1008.2007.01184 |
| 投稿时间：2007-05-25 |
| 基金项目:国家重点基础研究规划（“973”计划）（2005CB523304）. |
|
| Melatonin inhibits the regulation of hypothalamo-pituitary-adrenal axis in diabetic rats |
| XIA Ling1,ZHANG Chun-yang2,LIU Zhi-min1* |
| (1.Department of Endocrinology,Changzheng Hospital,Second Military Medical University,Shanghai 200003,China;2. Department of Endocrinology,Tongji Hospital,Tongji University,Shanghai 200065) |
| Abstract: |
| Objective：To study the effect of melatonin (Mel),a potent antioxidant,on the oxidative stress and the activity of hypothalamopituitaryadrenal axis in diabetic rats. Methods: Male SD rats were assigned to the following 4 groups:normal control (treated with 2% ethyl alcohol lavage\[NC,n=6\]),diabetes mellitus control (treated with 2% ethyl alcohol lavage \[DM,n=7\]),diabetes mellitus model group 1 (treated with Mel lavage \[10 mg·kg-1·d-1,DM+Mel1,n=6\]), diabetes mellitus model group 2 (treated with Mel lavage \[0.2 mg·kg-1·d-1,DM+Mel2,n=6\]).Diabetes in DM group, DM+Mel1 group and DM+Mel2 group was induced by intraperitoneal injection of streptozotacin(65 mg/kg).Blood glucose,body weight and adrenal gland weight/body weight(AW/BW) were determined in the 4 groups 12 weeks later;malondialdehyde(MDA) was examined with visible spectrophotometry; blood total cholesterol (TC)and triglyceride(TG) were examined with enzymology method; blood corticotrophinreleasing hormone(CRH),adrenocorticotrophic hormone(ACTH) and corticosterone(CORT) were examined with radioimmune method. Results: Blood glucose, MDA , TC, TG,CRH,ACTH,CORT and AW/BW in DM group were significantly higher than those in NC group(P<0.01); and the body weight of rats in DM group were significantly lower those of NC group(P<0.01). Compared with DM group, DM+Mel1 and DM+Mel2 group had a significantly lower blood glucose, MDA ,TC,TG and AW/BW (P<0.01 or P<0.05) and higher body weight (P<0.01). Blood CRH,ACTH and CORT were markedly decreased in DM+Mel1 group(P<0.01); blood CORT were markedly decreased in DM+Mel2 group (P<0.05); blood CRH and ACTH in DM+Mel2 group had no significant changes. Conclusion: Mel may lower the oxidase activity, improve metabolic disorder of glucose and fat, and inhibit the activity of hypothalamopituitaryadrenal axis in diabetic rats, exerting protective effect on diabetic rats. |
| Key words: melatonin diabetes mellitus,experimental hypothalamo-pituitary-adrenal axis |
