Department of Food and Nutrition, School of Food Engineering, University of Campinas , UNICAMP, Brazil.
J Sports Sci Med. 2013 Sep 1;12(3):461-6. eCollection 2013.
Running on a horizontal plane is known to increase the concentration of the stress biomarker heat-shock protein (HSP), but no comparison of the expression of HSP70 has yet been established between the uphill (predominantly concentric) and downhill (predominantly eccentric) muscle contractions exercise. The objective of the study was to investigate the relationships between eccentric and concentric contractions on the HSP70 response of the lung, kidney, gastrocnemius, soleus and heart. Twenty-four male Wistar weanling rats were divided into four groups: non-exercised and three different grades of treadmill exercise groups: horizontal, uphill (+7%) and downhill (-7% of inclination). At the optimal time-point of six hours after the exercise, serum uric acid, creatine kinase (CK) and lactate dehydrogenase (LDH) were determined by standard methods and HSP70 by the Western blot analysis. HSP70 responds differently to different types of running. For kidney, heart, soleus and gastrocnemius, the HSP70 expression increased, 230, 180, 150 and 120% respectively of the reference (horizontal). When the contraction was concentric (uphill) and compared to downhill the increase in response of HSP70 was greater in 80% for kidney, 75% for gastrocnemius, 60% for soleus and 280% for the heart. Uric acid was about 50% higher (0.64 ± 0.03 mg·dL(-1)) in the uphill group as compared to the horizontal or downhill groups. Similarly, the activities of serum CK and LDH were both 100% greater for both the uphill and downhill groups as compared to the horizontal group (2383 ± 253 and 647.00 ± 73 U/L, respectively). The responsiveness of HSP70 appeared to be quite different depending on the type of tissue, suggesting that the impact of exercise was not restricted to the muscles, but extended to the kidney tissue. The uphill exercise increases HSP70 beyond the eccentric type and the horizontal running was a lower HSP70 responsive stimulus. Key PointsExercise can induce increases in HSP70 in the lung, kidney and heart, and in the soleus and gastrocnemius muscles, probably due to systemic alterations such as hypoxia, increase in temperature and the production of free radicals.Predominantly concentric contractions (running uphill), seem to be the most efficient way of increasing the HSP70 concentrations in the different tissues, followed by eccentric contraction (downhill) and lastly the concentric-eccentric cycle (horizontal).The energy demand, already known to influence HSP70, appears not to be the only factor responsible for the response of these proteins, considering that for the kidney and the soleus muscle, downhill running was more efficient in raising the HSP70 response than horizontal running.Future research should explore the mechanisms by which the eccentric, concentric and eccentric-concentric contractions are capable of influencing the responses of the heat shock proteins, opening possibilities for increasing the levels of these proteins in desirable situations, such as to protect against excess free radicals or injuries.
在水平面上跑步已知会增加应激生物标志物热休克蛋白（HSP）的浓度，但尚未建立上坡（主要是向心收缩）和下坡（主要是离心收缩）肌肉收缩运动之间 HSP70 表达的比较。本研究的目的是研究离心和向心收缩对肺、肾、比目鱼肌、跖肌和心脏 HSP70 反应的关系。将 24 只雄性 Wistar 断奶大鼠分为四组：非运动组和三种不同坡度的跑步机运动组：水平、上坡（+7%坡度）和下坡（-7%坡度）。在运动后六小时的最佳时间点，通过标准方法测定血清尿酸、肌酸激酶（CK）和乳酸脱氢酶（LDH），并通过 Western blot 分析测定 HSP70。HSP70 对不同类型的跑步反应不同。对于肾脏、心脏、跖肌和比目鱼肌，HSP70 的表达分别增加了 230%、180%、150%和 120%（参考值为水平）。当收缩为向心（上坡）时，与下坡相比，HSP70 反应的增加幅度在肾脏中为 80%，在比目鱼肌中为 75%，在跖肌中为 60%，在心脏中为 280%。与水平或下坡组相比，上坡组的尿酸水平高约 50%（0.64±0.03mg·dL(-1)）。同样，上坡和下坡组的血清 CK 和 LDH 活性均比水平组高 100%（分别为 2383±253 和 647.00±73 U/L）。HSP70 的反应性似乎因组织类型而异，这表明运动的影响不仅限于肌肉，还扩展到肾脏组织。上坡运动使 HSP70 增加超过离心类型，而水平跑步则是一种 HSP70 反应性较低的刺激。关键点运动可引起肺、肾和心脏以及比目鱼肌和跖肌中 HSP70 的增加，可能是由于全身改变，如缺氧、温度升高和自由基产生。主要的向心收缩（上坡跑步）似乎是增加不同组织中 HSP70 浓度的最有效方法，其次是离心收缩（下坡），最后是向心-离心循环（水平）。能量需求，已知会影响 HSP70，似乎不是这些蛋白质反应的唯一因素，因为对于肾脏和跖肌，下坡跑步比水平跑步更能提高 HSP70 反应。未来的研究应探索离心、向心和离心-向心收缩能够影响热休克蛋白反应的机制，为在理想情况下增加这些蛋白质的水平开辟可能性，例如保护免受过量自由基或损伤。
