不同运动方式对自发性高血压大鼠骨骼肌纤维类型与代谢的影响

关键词：运动方式  自发性高血压大鼠  骨骼肌  纤维类型  代谢

Keywords:exercise modes  spontaneously hypertensive rats  skeletal muscle  fiber type  metabolism

摘要：

      摘要 目的：探讨不同运动方式对自发性高血压大鼠（spontaneously hypertensive rats，SHR）骨骼肌纤维类型及代谢的影响，为高血压患者最佳运动处方制定提供科学依据和有效方法。 方法：30只3月龄雄性SHR随机分为安静组（SHR sedentary，SHR-S）、中等强度持续有氧运动组（SHR moderate continuous aerobic training，SHR-MCAT）和高强度间歇运动组（SHR high-intensity interval training，SHR-HIIT），同时以10只雄性Wistar-Kyoto大鼠作为正常血压对照组（WKY）。WKY和SHR-S组安静饲养，SHR-MCT、SHR-HIT组分别进行8周持续和间歇跑台运动。实验后利用递增负荷跑台实验测定力竭时间（exhaust time，ET），分离胫骨前肌（快肌，Ⅱ型肌纤维为主）和比目鱼肌（慢肌，Ⅰ型肌纤维为主），利用比色法测定柠檬酸合酶（citrate synthase，CS）（有氧代谢标志物）和乳酸脱氢酶（lactate dehydrogenase，LDH）（无氧代谢标志物）活性，ATP酶染色法鉴定肌纤维类型（Ⅰ、Ⅱ）以及细胞横断面积（cross-sectional area，CSA）。 结果：a)与SHR-S组比较，SHR-HIIT组和SHR-MCAT组ET增加（P<0.05）；b)SHR-MCAT组比目鱼肌以及SHR-HIIT组比目鱼肌和胫骨前肌Ⅰ型肌纤维比例增加（P<0.05）、Ⅱ型肌纤维比例减少（P<0.05）、CSA升高（P<0.05）；c)SHR-MCAT组比目鱼肌CS活性升高（P<0.05）。d)SHR-HIIT比目鱼肌和胫骨前肌CS、LDH活性均升高（P<0.05）。与MCAT组比较，SHR-HIIT组ET、比目鱼肌和胫骨前肌CSA、CS和LDH活性均升高（P<0.05）。 结论：不同运动方式均能够促进SHR骨骼肌肥大、诱导肌纤维向抗疲劳亚型转换，进而改善肌肉代谢和运动能力，以高强度间歇运动效果为佳。

Abstract:

      Abstract Objective: To investigate effects of different training modes on skeletal muscle fiber type and metabolism in spontaneously hypertensive rats (SHR), hoping to provide evidence and method of optimal exercise prescription for hypertensive patients. Method: Thirty male SHR at 3 months of age were randomly divided into sedentary (SHR-S), ·moderate continuous aerobic training (SHR-MCAT) and high intensity interval training (SHR-HIIT) groups. Ten male Wistar-Kyoto rats were used as normotensive control group (WYK). Animals of SHR-S and WKY groups housed sedentarily while those of SHR-MCAT and SHR-HIIT groups conducted 8-week continuous or interval treadmill training respectively. 48h after training, exhaust time (ET) was detected by graded treadmill exercise test; anterior tibial muscle (fast muscle, mainly consist of type Ⅱ muscle fibre) and soleus muscle (slow muscle, mainly consist of type Ⅰ muscle fibre) were segregated, citrate synthase (CS) (marker of aerobic metabolism) and lactate dehydrogenase (LDH) (marker of anaerobic metabolism) activity were measured by colorimetry, muscle fiber types (Ⅰ and Ⅱ) and cross-sectional area (CSA) were determined by ATPase staining. Result: Compared with WKY group, ET of SHR-S group decreased sharply, it raised in SHR-MCAT group (P<0.05) and raised again in WKY group (P<0.05). Compared with SHR-S group, the proportion of type I fiber increased (P<0.05) and type Ⅱ decreased (P<0.05) in soleus of SHR-MCAT group (P<0.05) and they changes most in soleus and tibialis anterior of SHR-HIIT group. At the same time, the CSA of soleus and tibialis anterior both increased gradually from SHR-S group to SHR-MCAT group and then to be normalized in SHR-HIIT group. The activities of CS and LDH decreased in SHR-S group. MCAT increased the CS activity of soleus (P<0.05) and HIIT increased the CS and LDH activities of both soleus and tibialis anterior to normal. Conclusion: MCAT can promote the muscle area of the spontaneously hypertensive rats, remodel the muscle types from type Ⅱ to type Ⅰ, and increased the activities of CS and LDH in both type of muscles. The benefit of HIITis even more.