生理水平的雄激素对亚急性衰老小鼠学习记忆能力的影响

目的探讨生理剂量的外源性丙酸睾酮对亚急性衰老小鼠学习记忆能力的影响。方法将C57BL/6J雄性小鼠38只随机分为对照组(10只)、去势组(10只)、D半乳糖组(9只)、丙酸睾酮组(9只),3个月后对各组小鼠进行水迷宫和避暗穿梭实验,检测脑、肝脏组织的丙二醛、超氧化物歧化酶(SOD)水平,并由Nissl染色观测海马神经元的变化情况。结果去势组小鼠各项行为学指标均劣于对照组,大脑和肝脏的丙二醛水平明显升高,SOD水平明显下降(P0.05),大脑海马CA1区结构松散,神经元数量明显减少(P0.01);与去势组比较,D半乳糖组的行为学指标进一步恶化,大脑丙二醛水平明显升高,SOD水平明显下降,大脑海马CA1区结构紊乱,神经元丢失严重(P0.05);而丙酸睾酮组的上述各项指标与对照组比较,差异无统计学意义。结论雄激素可以逆转亚急性衰老小鼠学习记忆能力的衰退。降低体内氧自由基水平,改善大脑海马CA1区形态,增加CA1区神经元数量,可能是其机制之一。

Effects of androgen on learning and memory ability of subacute aging mice

Objective To explore the effect of exogenous testosterone propionate at physiological levels on learning and memory ability of subacute aging mice.Methods Thirty-eight 4-week-old male C57BL/6J mice were randomly divided into control group,castrated group,castrated + D-galactose group(D-galactose group) ,castrated+D-galactose+testosterone propionate group(testosterone propionate group).After 3 months,water maze test and step-through test were performed, the activity of SOD and MDA in the brain and liver were determined,and Nissl staining of hippocampal neurons was used to observe changes.Results Compared with control group,all the behavioral indicators of castrated group were deteriorated obviously,the level of oxygen free radicals in vivo increased,the structure of the CA1 area of hippocampus was looser and the number of neurons decreased.Compared with castrated group,the behavioral indicators of D-galactose group were further deteriorated,the structure of the CA1 area was disordered,the number of neurons reduced severely.The above-mentioned indicators in testosterone propionate group improved,and had no significant difference compared with the control group.Conclusion Both castration and D-galactose can undermine the ability of learning and memory in mice.Androgen can improve learning and memory ability.Reducing the level of oxygen free radicals in vivo ,improving the morphology of the CA1 area of hippocampus and increasing the number of neurons may be the mechanisms that testosterone improves the ability of learning and memory in aging mice.