负重爬梯与有氧跑台运动对糖尿病大鼠学习记忆能力的影响及其机制探讨

目的：研究负重爬梯与有氧跑台运动对糖尿病大鼠学习记忆能力的改善效果并探索其可能分子机制。方法：40只雄性大鼠，随机分为正常对照组（NC）、糖尿病对照组（DC）、糖尿病负重爬梯组（DL）和糖尿病有氧跑台组（DA），以单次腹腔注射链脲佐菌素构建糖尿病大鼠模型。DL组在晚上进行负重爬梯训练，10次/组×3组/天，每次间歇2 min，6天/周×6周；DA组在同一时间进行20 m/min的跑台训练，30 min/d。于造模成功和运动干预结束后采用Morris水迷宫检测大鼠的学习记忆能力；第2次水迷宫测试结束后断颈处死大鼠，采用RT-QPCR法检测大鼠海马内脑源性神经营养因子（BDNF）、TRKB、CREB mRNA表达水平。结果：与NC组相比，DC组大鼠海马BDNF、CREB基因表达显著下降，学习记忆能力显著降低。与DC组相比，DL和DA组大鼠海马BDNF、CREB基因表达显著上调，学习能力显著提高；DL大鼠海马TrkB基因显著上调，大鼠空间记忆能力显著改善，而DA组大鼠海马TrkB基因无显著变化，大鼠空间记忆能力无改善，与DA组相比，DL组大鼠海马TRKB、CREB基因显著上调。结论：有氧跑台运动与负重爬梯运动介导BDNF/TrkB/CREB信号通路对糖尿病大鼠的学习能力均有促进作用，而负重爬梯运动对糖尿病大鼠记忆能力的改善优于有氧运动方式。

Effects of weight-bearing ladder and aerobic treadmill exercise on learning and memory ability of diabetic rats and its mechanism

Objective: To investigate the effects of climb ladder and aerobic treadmill exercise on learning memory ability in diabetic rats and explore its possible mechanisms.Methods: Forty male rats were randomly divided into normal control group (NC), diabetic control group (DC), diabetic loading ladder group (DL) and diabetic aerobic treadmill group (DA), diabetes was induced by a single intraperitoneal injection of STZ. In the evening, the DL group were trained three cycle (10 times/cycle) with weight-bearing climbing ladder, 2 min intervals, 6 days/week, lasted for six weeks. The DA group was trained on a motor-driven treadmill at a speed of 20 m/min (0 incline), 30 min/day, 6 days/week, lasted for six weeks. Morris water maze was used to detect the learning and memory ability of rats after modeling success and after exercise intervention. After the last water maze test, the rats were killed to obtain the hippocampus. RT-QPCR was used to detect the gene expressions of brain derived neurophic factor (BDNF), tropomyosin receptor kinase B (TrkB) and cAMP-response element binding protein (CREB).Results: Compared with NC group, the expressions of BDNF and CREB gene in hippocampus of DC group and the learning and memory ability were significantly decreased. Compared with DC group, the expression of BDNF and CREB in hippocampus of DL and DA rats was significantly up-regulated and the learning ability was significantly increased. The TrkB gene of hippocampus in DL rats was significantly up-regulated and the spatial memory ability was significantly improved. Compared with the DA group, the TRKB and CREB genes in the hippocampus of DL group were significantly up-regulated.Conclusion: Aerobic treadmill exercise and weight-bearing ladder exercise have a positive effect on the learning ability of diabetic rats, while the weight-bearing ladder exercise improves the memory ability of diabetic rats better than aerobic exercise. These effects may be related to the up-regulation of BDNF/TrkB/CREB signaling pathway.